Le Mans 2014

Leading-Edge Motorsport Technology Since 1990

Le Mans 2014

Sports car racing’s ultimate technology test

CONTENTS/COMMENT

CONTENTS 5

NEWS The latest on Porsche’s rear bodywork, plus Strakka’s withdrawal

8

RACE ANALYSIS An analysis of the opening races of the WEC

12

AUDI R18 2014 The latest on Audi’s Le Mans challenger

18

TOYOTA TS040 Could this be Toyota’s year?

24

PORSCHE 919 HYBRID WThe return of a legend, but will it be

33

PORSCHE 991 RSR Porsche heavily updated its GT challenger at Bahrain in 2013

36

CORVETTE C7R American muscle car makes Le Mans debut

42

FERRARI 458 Revisiting the moment Ferraris new car was first unveiled

51

ASTON MARTIN VANTAGE Aston’s update kit was introduced at Sebring, 2013

52

EQUIVALENCE OF TECHNOLOGY EXPLAINED Ricardo Divila takes us through the complexities of EoT

56

I

The manufacturer LMP1 cars have stolen the limelight at Le Mans this year, and rightly so as the technology, the budget and the risk that each is taking is unprecedented at the endurance classic. While the power unit technology is the over-riding focus, teams have also been playing around with aerodynamics (see Porsche’s rear bodywork, Audi’s front splitter and Toyota’s rear wing) and with braking systems.

While this supplement brings you up to date with the latest developments in this fast-changing world, the undercurrent of privateer racing is also positive. The Rebellion Racing team was 8.6s off the fastest times at the test day, and the ACO and FIA responded with a weight break and a change to the fuel limits, which it ran at the test day already.

In LMP2, alongside the new Ligier featured in the latest edition of Racecar Engineering, there are new cars coming, including the Dome, the Wirth (HPD), Pilbeam, Adess, Tiga and Welter. The ACO has taken a great deal of care to get the LMP1 regulations correct, and has spent two years on the GT convergence talks, which abruptly stopped in May. Now, however, it will turn its attention to the privateer LMP2 category and again, must take care. Porsche and Toyota are both known to be carefully considering programmes that will allow them to compete in the US against these new designs.

The WEC and the TUSCC are both struggling for entries in the class this year. The LMP2 class, and the LMGT-Am are both crucial categories to the success of endurance racing. There will be changes, but for teams, and drivers, value of racing needs to be maintained.

ANDREW COTTON Editor

NISSAN ZEOD Peter Wright’s analysis of this revolutionary carv

60

40KG POWERPLANT RML developed a lightweight engine to produce 400bhp

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DATABYTES Cosworth on dealing with the data at Le Mans, 2014 EDITED BY: Andrew Cotton, Sam Collins and Kevin Younger DESIGN: Dave Oswald

LE MANS 2014 3

LE MANS – NEWSDESK

Flexible bodywork sees Porsche legality questioned

Flexing body panels or movable aero? All the LMP1 teams may be in breach of regs, but the Porsches are the most noticeable

Legality of the new Porsche 919 has been questioned following the Le Mans test day.

Rival teams noticed that at high speed the engine cover of the car was visibly deflecting, probably causing a reduction in drag. This could be in breach of article 3.4 of the technical regs which states that ‘Movable bodywork parts/elements are forbidden when the car is in motion’ and also that ‘the rear bodywork viewed from above’ should have ‘a continuous unbroken surface without cut-outs.’

4 LE MANS 2014

Additionally the rear bodywork extends a few millimetres beyond the rear of the diffuser, something that may contravene article 3.5.2 of the technical regulations which states that ‘No part of the diffuser must be more than 200mm above the reference surface and its rear end must be plumb (Flush) with the perimeter of the bodywork (rear wing removed)’.

Shortly before the teams arrived at Le Mans for the start of testing, the FIA warned that it was aware that all three teams were experimenting

FOR FULL ANALYSIS CLICK HERE

with flexible bodywork and that at Spa, Audi, Porsche and Toyota were all strictly speaking illegal. ‘We have observed during scrutineering that each of your cars had some flexibility in order to prevent any damaging of the underside of cockpit in case of unwanted passage out of track or on kerbs,’ a message sent to all teams by the governing body stated. ‘Formally speaking, this contravenes article 3.4 of the LMP1 regulations.

However as it seems indispensable and used by all of you, we agree not to apply strictly this article for this specific part. In order to be fair to everybody, we will accept a flexibility in that point of: 10mm under 500 daN. To be absolutely clear, we make it mandatory to have a stop effect and that this deflection cannot under no circumstances be more than 15mm. Moreover we remind you that the FIA reserves the right to introduce load/deflection tests on any part of the bodywork which appears to be (or is suspected of), moving whilst the car is in motion.’

Porsche claimed that when the bodywork was attached to the cover in the centre of the car, the continuous line was maintained and therefore was legal. No protest was lodged.

TESTING CRASH FORCES STRAKKA TO PULL OUT

The race debut of the brand new Strakka-DOME S103 has again been delayed, this time due to a heavy crash. In the week leading up to the Le Mans test day the Strakka team was conducting performance tests to validate its low drag aerodynamic configuration when a crash at the notorious Eau Rouge corner curtailed running. The resulting damage was too severe for the team to prepare for the Le Mans 24 Hours this year. The car will make its WEC debut later in the season.

The car has been designed by Japanese firm DOME and is thought to be one of the most aerodynamically advanced LMP2 spec cars ever built. Construction of the car is handled by the English Strakka team at their Silverstone base.

Deltawing promotes road car concept DeltaWing Technologies has revealed how its concept could look as a street-legal, fourpassenger car. Using Ben Bowlby’s general concept of half the weight, half the power, half the drag the Deltawing road car has many of the benefits of the competition version used at Le Mans and in the TUSCC. Intended as a solution for manufacturers facing more stringent fuel economy and emissions standards, the platform offers efficiency benefits whether using new generation smaller and lighter high efficiency petrol or diesel powertrains, alternative fuels such as compressed natural gas (CNG), or hybrid and allelectric powerplants. DeltaWing has released the concept in order to promote its intention to partner with mass-market auto companies that share its vision rather than manufacture independently, thus offering cars with the DeltaWing’s lightweight architecture to a broad global audience and significantly expanding the design’s efficiency and environmental benefits.

Company executives have been meeting with car makers that support the goal of bringing the DeltaWing® vehicle architecture and its lightweight and efficiency technologies to road cars to help meet the CAFE (Corporate Average Fuel Economy) standard of 54.5 mpg by model year 2025.

‘Many of the aerodynamic, lightweight and handling benefits of the race car can translate to the street,’ said Don Panoz, chairman of

DeltaWing Technologies Inc. ‘We are competing at the highest levels of road racing with half the weight, half the horsepower, and nearly half of the fuel consumption. We believe we can deliver similar results on the street without compromising safety, comfort and performance.

We have a formula that’s highly efficient and still fun to drive.’

One fly in the ointment may be increasing pedestrian safety regulations that could be tricky to adopt to the front of the vehicle. Meanwhile some people will perhaps struggle with the aesthetics of such an unconventional looking car.

LE MANS 2014 5

LE MANS – NEWSDESK

Toyota brake legality challenged at Le Mans The legality of Toyota’s braking system has been challenged at Le Mans. Whilst there is no suggestion of cheating or underhand behaviour there has been some debate about the way its brakes are managed. ‘A clarification from the FIA was issued and that shows the others that our system is fully legal’ argues Pascal Vasselon.

The brake by wire layout on the TS040 has an automatic ‘brake migration’ system that sends

The technology is not unique to Toyota and features on most, if not all, Formula 1 cars. Toyota did not feel that the concept was especially confidential or indeed illegal as its implementation seems rather obvious on a hybrid competition car. However once rival manufacturers became aware of the system they complained to the FIA about its use, claiming that it breaches two parts of the 2014 LMP1 technical regulations.

Article 14.1 states that: The only connection allowed between the two circuits is a mechanical system for adjusting brake force balance between the front and rear axles.

Article 14.7 states that For vehicles with a Kinetic ERS, a specific braking system is allowed.

Its function is to ensure the braking of the car strictly in conformity with the order given by the driver.

Its function cannot be, in any circumstances, to provide the driver with any additional support.

The system may be active, but must: Ensure balanced and stable braking, whatever the amount of energy recovered. It must ensure a constant front / rear braking load distribution (sum of the electrical and hydraulic efforts) which can be adjusted only manually by the driver.

Following the requests for clarification from Toyota’s rivals the governing body issued a technical directive regarding brake bias control: ‘Following some questions about the ERS specific brake system, we feel important to clarify that in reference to articles 14.7.1 and 14.7.2: 1) A system that complies with LMP1 regulations cannot:

•

the bias forwards or rearwards as the car travels deeper into the corner. In essence it is a form of active brake bias, as the electronic management system on the car manages it automatically.

If a driver hits the pedal and feels significant rear locking, the next time he arrives at that corner he would adjust the brake bias forwards to prevent it on a standard racing car. But sometimes as he starts to turn into the corner front locking can result as the wheels are unloaded. The Toyota system, which is in essence identical to those used in F1, mitigates this by using a brake migration tool to automatically send the bias rearwards again as the braking event continues. The drivers have control of how extreme this effect is by using rotary thumb switches on the steering wheel.

• •

Frazer Nash Prototype project stalls The Frazer Nash brand has evaluated a 2015 Le Mans return as the Garage 56 entry. Designs were at an advanced stage for the Le Mans Prototype before the project apparently stalled. It had been hoped that the programme could have been announced at the ACO press conference ahead of the 2014 Le Mans 24 Hours, but for reasons that are not clear the announcement appears to have been cancelled.

Racecar Engineering understands that the project had been granted the Garage 56 ‘innovative technology’ entry into the 2015 Le Mans 24 Hours ahead of a full 2016 LMP1 programme. Sergio Rinland’s Astauto design consultancy had been commissioned by Frazer Nash to

6 LE MANS 2014

develop the early designs of the car which featured a highly innovative powertrain.

Frazer-Nash first contested the Le Mans 24 Hours in 1935 when it failed to finish but in 1949 it finished third overall. The last time the brand contested the race was in 1957 when the company ceased car production, it was later absorbed by Porsche Cars GB. Today the Frazer-Nash Group, which also incorporates Bristol Cars, is owned by technology entrepreneur Kamal Siddiqi. It is currently focussed on developing powertrain technology, with range extended hybrids a particular speciality.

In 2009 Frazer Nash built and tested a concept supercar called the Namir (pictured), which was set to lend its technology to a new Bristol Sportscar. This gives some hints to what the LMP1 power train may have been. The car was to be fitted with four separate electric motors, each driving one of the cars wheels, whilst an 800cc rotary engine would act as a generator powering a bank of Lithium ion battery cells. It was to feature a significant amount of torque vectoring via a bespoke ‘digital differential.’

•

Have any sort of balance adjustment to compensate automatically disc/pad wear or wheel locking.

2) A system that complies with LMP1 regulations can: Have a possibility of selection by the driver of the value of a nominal brake balance (by an HMI like a button/potentiometer, for example) Have a brake balance related to the brake pressure applied by the driver through a pre-definite law (which avoids any possibility of electronic anti-lock system), provided the relation pedal-pressure / brake balance is monotone and without any inflexion point (curvature always the same sign), like could be got from mechanical devices.

Have a possibility of selection by the driver of the law defined above (relation pedal pressure/brake balance. Selection made by another HMI like a button, for example)’ This guarantees that brake balance is under the direct control of the driver through its selection and the pedal pressure he applies. For a definite set-up chosen by the driver, and a definite pedal pressure, the brake balance remains at a constant value, independently of the level of energy recovered or lock of the wheel.

Toyota has been very open about the use of the system on its cars and does not believe it to be illegal, indeed the layout has even been detailed in Racecar Engineering in the past!

Indeed the Toyota team seemed surprised that its rivals were not doing the same as they were!

Toyota technical boss Pascal Vasselon insists that the system is fully compliant with the regulations and that it has not changed its operation.

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LOTUS T129 LMP1 REVEALED AT LE MANS The much-delayed Lotus T129 LMP1 car has been revealed at Le Mans. Originally designed to accept the NBE built Audi DTM V8, the rear of the car has had to be extensively reworked to accept the new AER P60 twin turbo V6 engine. The car could be seen as part of the HRT family line with the Holzer Group in Germany playing a key role. A solitary example of the T129 will contest some of the remaining World Endurance Championship races in 2014.

RACE ANALYSIS

The plot thickens In the build up to Le Mans, a place that has a knack for delivering unexpected twists, we examine the contenders

By PAUL TRUSWELL

W

ith two rounds of the 2014 World Endurance Championship gone, there have been plenty of clues as to what this year’s Le Mans 24-hour race might have in store.

However, such has been the impact of the changes to the regulations this year, that the indications of the first races might turn out to be as misleading as the red herrings in the best Agatha Christie novel.

Like the opening chapters of all the best whodunnits, the opening round at Silverstone served to introduce the characters, and gave us some fascinating glimpses of what we might expect, but without giving very much away. The weather saw to that.

Motive and opportunity… Toyota TS040 and Porsche 919 go head to head in the rain at Silverstone

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It is worth looking at the first 20 laps though, which were as breathtaking a period of motor-racing as seasoned campaigners have seen for many a year. Bearing in mind that not only was this the first time that a works Porsche prototype had raced in anger for 15 years, and that Audi and Toyota had started the season with completely new designs, this was no gentle rolling out and building up to speed: these were the opening salvoes of what looks like being a brutal war of a season ahead.

In the circumstances, it is hardly surprising that the Porsches were left behind a little, but nevertheless, the following table is interesting, showing the best and average lap times for those first twenty laps.

The astonishing thing is that, if one compares this to the opening 20 laps of last year’s Silverstone 6-hours, which was of course the opening round in the 2013 World Endurance Championship, the times are not that different. Such a small change in lap times – an improvement for Toyota, and a small deterioration for Audi – does not do justice to the fundamental changes of the regulations.

In those same 20 laps, in 2013, the Toyotas would have used approximately 62 litres of petrol, the Audis 51 litres of diesel. This year, the regulations dictated that the cars used a maximum of 45 litres diesel and in Toyota’s case 54 litres of petrol. Maybe not the 30% reduction that has been mentioned in some quarters, but

nevertheless a substantial reduction (12-15%), and, in Toyota’s case, an improvement of lap times as well.

When the rain came down at Silverstone on Easter Sunday this year, Toyota hedged its bets, putting one car (the no 7) on to intermediate tyres and the other on to a full wet, while Audi left both cars out on slicks, hoping to bring them in at the end of the fuel window, by which time, they hoped, the intentions of the weather might be clearer. It was a bad call, both cars proving undriveable in the conditions, and falling further and further back (or off the circuit) as the race progressed.

Developments at Spa

When the heavens opened with less than an hour of the race remaining, the decision was taken to halt the race, but as an exercise in establishing the pecking order in terms of Audi, Toyota and Porsche, changing weather conditions made it all rather fruitless. To return to the theatrical, whodunnit theme: the audience was left, as the interval curtain fell, knowing the characters but in a state of mild confusion about who had done what.

So we settled into our seats for a spellbinding six hours in the Ardennes; run without interruption, not from rain, the safety car, or even any significant retirements. And as the chequered flag fell, it was fairly clear to the

TABLE HEADLINE No. 1 2 7 8 14 20

Car Audi R18 e-tron Quattro Audi R18 e-tron Quattro Toyota TS040 Hybrid Toyota TS040 Hybrid Porsche 919 Hybrid Porsche 919 Hybrid

Driver Di Grassi Lotterer Wurz Buemi Jani Bernhard

Best 1m 44.656s 1m 44.217s 1m 44.326s 1m 44.708s 1m 45.452s 1m 45.245s

Average 1m 46.104s 1m 45.903s 1m 45.933s 1m 46.304s 1m 47.223s 1m 46.733s

TABLE HEADLINE No.

Car

Driver

Best

Average

1

Audi R18 e-tron quattro

Tréluyer

1m 43.995s

1m 45.691s

2

Audi R18 e-tron quattro

McNish

1m 43.710s

1m 45.326s

7

Toyota TS040 Hybrid

Wurz

1m 44.296s

1m 47.711s

8

Toyota TS040 Hybrid

Davidson

1m 44.047s

1m 46.681s

AVERAGE OF BEST 100 LAPS COMPLETED: Toyota Porsche Toyota Audi

8 14 / 20 7 1

Spa 2m 03.289s 2m 03.602s 2m 03.774s 2m 04.153s

Silverstone 1m 46.981s 1m 48.414s 1m 46.733s

TABLE HEADLINE Manufacturer Audi Toyota Porsche

Tyre change (average) 21.9s 21.6s 25.5s

Fuelling time (average) 33.0s 33.5s 33.2s

“Such a small change in lap times – an improvement for Toyota, and a small deterioration for Audi – does not do justice to the fundamental nature of change in the regulations”

LE MANS 2014 9

TEST REPORT SPA FIRST-SECOND HALF AVERAGES Spa Audi

Toyota Porsche

1 2 3 7 8 14 20

Best 50 laps in first half 2m 04.181s 2m 04.702s 2m 04.859s 2m 03.621s 2m 03.282s 2m 03.338s 2m 04.360s

Best 50 laps in second half 2m 04.111s 2m 04.588s 2m 04.865s 2m 03.930s 2m 03.329s 2m 03.928s 2m 04.622s

SPA 100 LAP AVERAGES Spa Audi

Toyota Porsche

1 2 3 7 8 14 20

100 lap straight average 2m 04.153.s 2m 04.644s 2m 04.861s 2m 03.774s 2m 03.289s 2m 03.602s 2m 04.490s

0.70% 1.10% 1.28% 0.39% 0.00% 0.25% 0.97%

SPA SECTORT TIMES Spa

50 lap averages Sector 1 SF to Les Combes Audi 1 35.180s 2 35.373s 3 34.616s Toyota 7 34.309s 8 34.165s Porsche 14 34.148s 20 34.163s

audience that Toyota had done the best job over the winter (and before that), of building a car to extract the maximum from the 2014 regulations. Putting on my Miss Marple hat, let’s look at the evidence.

First of all, Porsche. The 919 Hybrid has certainly not disappointed in its first two races.

One pole position (by more than half a second), one podium and only one retirement out of four starts is a good solid start of which the whole team can be proud, particularly bearing in mind that the team has focussed solely on its Le Mans aero-configuration car.

It is interesting to note that the team made a positive step forward between Silverstone and Spa Francorchamps, a testament to the company’s rate of development with the new car. At Spa, the no 14 car was just 0.25 per cent slower than the winning Toyota, taking the average of the fastest 100 laps of both cars.

Sector 2 Les Combes to Stavelot 56.271s 56.360s 57.913s 57.398s 57.180s 57.751s 58.249s

Sector 3 Stavelot to SF 31.846s 32.017s 31.491s 31.105s 31.016s 30.749s 31.013s

The car is undeniably quick though. At Spa, taking the average of the best 50 times in each sector, Porsche no 14 was fastest in both sector 1 and sector 3. This is the clearest indication that its hybrid power is usable wherever it wants it.

Toyota is likely very envious.

Porsche has to address two issues before Le Mans. The first is reliability. Although, as I have already stated, the cars have performed well in both races up to now, they have yet to manage a six hour race without an unscheduled pit stop.

Second, the team is losing time in the pits.

Using the data from Spa, I have calculated the average time spent in the pits changing wheels.

The pit lane is a known length, (386.6m) so the time spent driving the length of it at 60kph can easily be worked out. Similarly, the time spent refuelling can also be subtracted from the total time spent in the pits. The results (said Miss Marple) are clear to see:

“Had it not been for the two slow laps that Romain Dumas was forced to complete at Spa, Porsche would certainly have improved on its third place at Silverstone” This compares with a whopping 1.6 per cent difference at Silverstone. Had it not been for the two slow laps that Romain Dumas was forced to complete at Spa, then Porsche would certainly have improved on its third place at Silverstone.

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At Le Mans, I expect Porsche to change the wheels on each car around fifteen times.

That means they will have to catch up nearly a minute, unless they can sharpen up the pit stop procedures!

In the Spa sunshine the Porsche 919’s power was evident, but reliability is still a problem

Now, what about Audi (sitting innocently in the drawing-room armchair)? There is no question that two broken chassis at Silverstone was a disappointment. And the second place at Spa was somewhat fortuitous, the other two cars finishing lap(s) behind in the final two LMP1-H class positions.

Sometimes though, it is the seemingly innocent that have something to hide. Remember that Audi only ran its Le Mans-spec car at Spa in the hands of Bonanomi and Albuquerque, the two least experienced LMP1 hands in the field. And don’t forget that the 2014 Le Mans configuration is much more different to its high-downforce cousin than last year’s two configurations of car.

It is worth mentioning that two of the Audis (nos.

1 and 3) were the only two cars to complete the race at Spa without an unscheduled stop. Also, the no. 3 completed the race with just six stops – the only LMP1 car to do so. Interestingly, the no. 3 car was not able to – or at least chose not to – double stint its tyres. By contrast, the no. 1 high-downforce car changed tyres only three times during the race.

I may be reading more into this that I should, but it does occur to me that Audi will have been gathering data on fuel consumption, tyre wear and lap times. The fact that the no 1 Audi was quickest in sector 2, along with Lotterer’s performance in the early laps at Silverstone shows that there isn’t much wrong with the power being developed from the

(less fuel-efficient) low-power hybrid option.

It is also interesting to note that if you split the race into two halves, and compare the average fastest 50 lap times in the first half of the race with the average 50 lap times in the second half of the race, Audi is the only manufacturer whose lap times improve.

Audi may not go to Le Mans as favourites, but they have made a speciality of winning with the slower car in the past. The difference is manageable, and it would be a brave man who bet against them doing so again.

Toyota on target

Toyota? Well, they’re holding the smoking gun, aren’t they? Two wins out of two races and four podium finishes from four starts is about as good as it can get. And at the third time of asking, surely a win at Le Mans is on the cards this year?

Well, yes it is, but those with long memories in Tokyo will look back at 1998 and 1999 when GT-Ones led the race having started on the front row in both those years. A Toyota victory looked likely in 1994, too, until gearbox trouble stranded Jeff Krosnoff with around an hour and a half remaining.

If Toyota is to win Le Mans this year, they will have to be perfect. The cars have been plainly faster at both Silverstone and Spa. The pit stop

times from Spa demonstrate that they are quicker than Audi in the pits. The win is theirs for the taking. The super-capacitor may deliver the power less uniformly than the Porsche, but the car can negotiate traffic with astonishing agility.

Hidden clues

There is something that doesn’t quite fit, though.

And just before the curtain falls on this particular piece of drama, let me say this. The difference in lap times between the two Toyotas, both at Silverstone and Spa is substantial. I can’t believe that there is that much differential in the drivers, and the team has stated that the cars were in the same configuration – high downforce at Silverstone and low downforce at Spa. So it must be down to car set up. And if car set up can make that much of a difference, then it must be an

There is no point in running the engine lean to get better range, unless you are right on the edge of being able to do another lap or you can go faster, leaner

incredibly sensitive thing to set up.

Technically, just getting the hybrid to work efficiently is complex, so I wonder if there is a danger that the car might just drop off a performance line somewhere. It is something that the team needs to understand, to maintain its position as favourite.

In some ways, this year’s regulations have removed a good deal of the opportunities for technical cleverness. The rules decree a maximum instantaneous fuel usage, as well as a limit on the amount of energy (i.e. fuel) used per lap (worked out over a three lap average).

Therefore, there is no point in running the engine lean to get a better range, unless you are right on the edge of being able to go another lap, or you can actually go faster, leaner. For Porsche, it is possible that they will be able to achieve 14 laps at Le Mans, but calculations show that Audi and Toyota will need poor weather or ‘slow-zones’ to be able to achieve that distance between refuelling.

Thereafter it is all about the driver’s ability to adapt to the driving technique required to optimise performance within the fuel consumption constraints, his ability to conserve tyres, and the team’s ability to turn the car around in the pits. Although Toyota has to start the race as favourite to win on previous form, it is by no means certain that it will do so..

LE MANS 2014 11

2014 AUDI R18

Generation H Audi has launched its brand new R18, which couples the firm’s tried-and-tested diesel engine with an electro-magnetic flywheel.

By ANDREW COTTON

“The biggest challenge is that the diesel will always be heavier than gasoline, so we made the biggest effort to use the rules in a proper way” 12 LE MANS 2014

A

udi’s all-new R18 TDI was given its first public appearance shortly before Christmas in 2013, but pre-season testing highlighted problems with the technology in the car coupled with the weight of the diesel engine. During the opening races of 2014 it has shown that, despite running tried and tested Kinetic Energy Recovery systems, it lags behind the opposition in both pace and, by regulation, in fuel economy. The German company did not manage to make use of its MGU-H, dropping the technology which would have used the exhaust gasses to power a small electric motor, as the technology was unproven, and the weight up high meant that it compromised weight distribution. Audi chose to run in the 2MJ category using KERS only (the MGU-H was never going to be included in this total but was only designed to reduce turbo lag), but a change in the regulations, the now-famous Appendix B, means that the Audi will start Le Mans at a disadvantage to the Toyota and Porsche (see

Peter Wright’s feature in Racecar Engineering V24N7 for full details). Yet, the German manufacturer races well, and given the unreliability of the Porsche 919 Hybrid in the opening two races, can realistically challenge for the podium at least at Le Mans, and for overall honours if it can push Toyota into making a mistake. Those who write off Audi do so at their peril – the team always races well at Le Mans.

Drama in KERS

The kinetic energy recovery system is completely new, but will continue to drive the front axles, with the result that the car will still retain its four-wheel drive characteristics. Audi expects the new car to use 30 per cent less fuel than the 2013 version, although in the first two races, fuel savings were significantly less than those targeted by the ACO in its innovative regulations.

The chassis is completely new, to meet with new regulations that require a higher cockpit, raised

LE MANS 2014 13

2014 AUDI R18 Audi expects the new car to use 30 per cent less fuel, returning to economy over power in the 2014 car

20mm compared to the 2013 car, while the car is narrower by 100mm. The front wheels are narrower, meaning that the bodywork can be too, helping to improve aerodynamic efficiency. The weight has also been reduced by regulation, from 915kg in 2013 to 850kg for a non-hybrid car, and 870kg for a hybrid car.

Aerodynamic development has been a feature of this year’s Le Mans 24 hours, but common to all manufacturer cars was flexibility built into the floor to protect the monocoque in the event of hitting a kerb. While this was strictly against the regulations, due to a potential performance advantage that could be gained by the teams using such systems, the FIA Endurance Committee elected to allow teams to continue using such floors.

14 LE MANS 2014

‘Regarding the front part skid-block, we have observed during scrutineering that each of your cars had some flexibility in order to prevent any damaging of the underside of cockpit in case of unwanted passage out of track or on kerbs,’ read the document issued by the Enduranc Committee on May 20, 2014.

‘Formally speaking this contravenes article 3.4 of the LMP1 regulations. However as it seems indispensable and used by all of you, we agree not to apply strictly this article for this specific part. In order to be fair to everybody, we will accept a flexibility in that point of: 10 mm under 500 daN. To be absolutely clear, we make it mandatory to have a stop effect and that this deflection cannot under no circumstances be more than 15 mm.’

Weighty issues

New cockpit regulations, narrower chassis and an all-new set of side-intrusion safety elements required all manufacturers to build new cars, but the reduction in base weight, coupled with the extra weight of the safety structures, caused Audi to have to revisit every part of the car in a bid to get the package down below the minimum total weight and still have ballast to play with.

The switch from Dallara as the chassis maker to another Italian firm – Ycom –was just part of an overall review of the complete car. ‘We reviewed the possibilities and kept the core technology of layout and packaging with the chassis, and the consortium of how to manufacture has always been a puzzle

“The most important thing about the engine is that it has to last. Car people hate me for that”

organised by Dallara,’ says Christopher Reinke, head of LMP1 at Audi. ‘We look at who is best, because we guide the process – and we felt that there was a more optimum possibility for us. For sure the new weight regulation is very challenging, as we try to put more technology in the car, with a dual hybrid system. It goes in hand with what the road car tries to achieve, trying to lower the weight spiral while increasing the hybrid performance.

‘The car is 100mm narrower and we have smaller wheels. After that it starts to get tricky. We had to apply the same theory when we created the ultra and e-tron. You have to look at everything, and to question every single thing. What might make sense from a technical point of view we always have

to question for the weight.’

Audi engineers went through the chassis, the engine, gearbox, and all structures in a bid to save weight, and achieved it, although the MGU-H was sacrificed before the season started.

‘We had to fit another system in, and we had to get the weight out of the car,’ said Audi’s leader of electric technology, Thomas Laudenbach. ‘The biggest challenge is that the diesel will always be heavier than gasoline, so we made the biggest effort to use the rules in a proper way. Last year we had to gain weight, but before I came here they worked on every little bit. Last year’s car there wasn’t enough ballast to just take it out of the car, we had to look at everything – the engine, the gearbox, the structured parts, the

monocoque, everywhere.’

At the Geneva Show in March, Audi announced that it would not run the MGU-H on the grounds of weight distribution.

Engineers estimate that the diesel engine is up to 50kg heavier than petrol and, while this is compensated in the regulations, it still prevented them from debuting the MGU-H. ‘It is the right way to go, but it is a tough way to go,’ said Laudenbach of the technology.

‘If you have an MGU in the exhaust system, you will always be in the situation to use it as energy recovery as a boost, but it costs you energy. You can use it for an anti-lag if you have a problem with it, because it is not the most efficient way of using it. As a first step, you would be happy if you don’t need it.’

LE MANS 2014 15

2014 AUDI R18

Power Unit

Each of the manufacturers has arrived with a completely different engine concept. Porsche has a 2-litre V4 engine, Toyota a 3.7-litre V8 gasoline, while Audi has increased capacity to a 4-litre V6 diesel engine, which is all new to cope with the new fuel flow regulations that force manufacturers to run their engines lean on fuel while still delivering high power.

‘It is a brand new engine,’ says head of engine technology Ulrich Baretzky. ‘It is a brand new rulebook – the conception is completely new. We could never do for next year what we did from 2012-2013 – that would be the wrong way to go.’ The engine has a 120 degree V-angle, has four valves per cylinder and has retained the Garrett VTG turbo. It is a direct injection TDI with a fully stressed aluminium crank case. The now dropped MGU-H was to work with the turbo to reduce lag. ‘The MGU-H is less of an influence in the design of the engine – it is more complex in terms of overall

Larger crash structures are needed in the new regulations, and in the case of the new R18, this extends beyond the end of the rear bodywork

HYBRID DEVELOPMENT

T

homas Laudenbach left his position at Porsche’s head of powertrain and took up the job of heading up a new department within Audi to develop the hybrid system and its efficiency.

His arrival was welcomed by the head of Audi’s engine programme, Ulrich Baretzky.

Laudenbach was appointed to his post early in 2013, and believes that the regulations have been formed in such a way that the development of the new generation R18 will benefit the production car team. It is understood that one area in which the team has learned valuable lessons is writing its own software codes.

‘In general, we are always looking at the road cars,’ says Laudenbach. ‘That is where it starts, so the road cars we have the issue with CO2, that is not a new story and manufacturers are working on all sorts of solutions, and a very big area is electricity in a road car.

‘We’re coming from a plug-in hybrid to an electric range, and racing has taken that challenge on, promoting technology. A racecar is used in a different way to a road car, but you still have a conjunction between the two. Then you look at the rules, and there is a clear tendency towards everything becoming too expensive, so we have to restrict. Not in the new technologies, but we restrict a lot of other things that we’ve had in the cars for many years, because the steps are not that big, and in general they leave it open for all sorts of hybrid systems. This is an area that is growing, and the opportunities are great.

‘If you look at the R18, it is integrated. For nearly 100 years, the driver was used to one source of power – the internal combustion engine. Now they have two or even more, but you still have one pedal

so someone else has to take over the coordination of the power sources in an efficient way. The driver can’t do it, or they would need two or three pedals. Since we have more than one power source in the car, you have to use it in the most intelligent and efficient way. Before it was more intelligent in power density and from 2014 on it is intelligent in efficiency – and there you need a lot of electronic control systems.

‘Now the work powertrain becomes a complete new definition because it is extremely complex system of various components, ICE, gearbox and some power sources, and obviously the units where the energy that they recuperate is stored. That makes it complex. It needs to be efficient and lightweight, and it’s more complex than we had. Compared to other technologies, this is relatively new. The electric

and the hybrid is more. The efficiency of a hybrid system doesn’t matter because you cannot release more energy than the regulations allow.

‘With the energy release, there are certain megajoule classes and you choose which one you want to be in, because that influences the amount of fuel that you can put in. You can harvest as much as you want, but you cannot release it.

‘Software is a main area of development because the various electric motors in the car cannot be controlled by a single pedal. You have so many different situations, like when it is raining for example.

It will have to be a very intelligent system onboard. You have a certain amount of energy per lap, and we want to use that amount of energy spot on. We don’t want to be five per cent down, because then you will lose a lot of lap time. To make sure that on every lap you use the right amount of fuel, a difference of one or two per cent will cost you tenths of a second in lap time.’

As the fleet production car CO2 emissions fall towards 2020, when the average needs to be less than 95g/km, efficiency is key. Why, then, does the new R18 continue to feature a flywheel rather than the batteries that are sold in the production hybrids?

‘Something that relates to the road car, you have the intelligent handling of energy,’ says Laudenbach.

‘First of all the car has be good at the races.

We chose the best possibility for the race, and not that much in terms of components that can be transferred to the road car. Software, strategy, and certain efficiencies, they can be transferred to the road car. The storage system is different, but there is still a lot of synergy.’

“For nearly 100 years, the driver was used to one source of power – the internal combustion engine.

Now they have two, or even more”

16 LE MANS 2014

motor is new in the automotive application, so hopefully the steps will be great and that is the whole story. That is where you have to make efficiency.’

An efficient race powertrain is going to be a complex feature, as not only will it have to deliver precisely the correct amount of fuel per lap under normal racing conditions, it will also have to cope with such variables as weather and safety car periods.

‘You have got a playground of strategy and you have to use the fuel in the most efficient way, says Laudenbach. ‘We all know that the ICE has losses – the efficiency is below 50 per cent,

Different manufacturers have different solutions to the shape of the cockpit, as per the new regulations – here’s Audi’s

energy management in the car,’ says Baretzky.

You have an amount of energy then you have to use it, and if you waste it you are lost. You have to have the management to do this, part of it by the driver, and some by the electronics.

‘The engine design methodology has not changed at all because it was always part of our job to run the engine efficiently. The only thing that has changed is the proportion – only economy or only power – and it has moved more towards economy. You have less quantities of pure performance in the lap than before to take the efficiency and to use the energy, because the energy is still used by the combustion engine, and nothing else.’

Each of the engines runs with the Gill Fuel Flow meter. Audi has three sensors per car – one to measure the flow, another as a back up as with every LMP1 on the grid.

Uniquely, the diesel carries a third to measure the return flow. While Audi, along with every other manufacturer, has encountered problems achieving the accuracy level of 0.5 per cent set by the FIA, it is not necessarily down to the meter. Drift can occur for many reasons, including the sensor coping in a harsh environment, and all manufacturers have been careful not to be overly critical of the young technology. What Audi will say, categorically, is that the sensor should have been delivered much earlier, although commercial issues within Gill Sensors prevented this from happening.

Energy recovery

Audi continues with the flywheel system that was built for them by Williams Hybrid Power, but WHP was sold in February to British company GKN, which plans to use the technology for commercial transport solutions, including buses and trains. Audi’s problem is that, should GKN elect not to continue its racing programme beyond 2014, the company will be unable to change the flywheel storage system and will be unable to compete in a much higher class than the 2MJ already chosen this year. Building a flywheel capable of more storage with another company is not a viable option, according to Audi, nor is switching technology altogether and using batteries, although this option is under constant review. There is no doubt that Audi must try for a larger storage system, although how it achieves it has yet to be established.

‘If you go to battery, you have far more energy there,’ says Laudenbach. ‘A flywheel is very good at power, but the amount of energy is less, and in terms of the solution for what we need, this is the lightest one. I am not saying that the flywheel is the best solution, but for what we need and what we know so far, it is the lightest. Nobody would build one into a road car – it has different demands. We are looking at it, and at other solutions, but for what we need now it is the best solution, from a technical point of view.’

LASER LIGHTS

A

udi has had another stab at improving its light system on the new generation R18 and has introduced a laser light system in addition to the LEDs that have come to be an iconic feature of the car.

A blue laser beam backlights a yellow phosphorous crystal lens through which the light beam is then emitted. This new light source then provides even more homogenous lighting of the road.

The last time Audi introduced its super-bright lighting system, it blinded the GTE drivers and could have been a contributory factor in Mike Rockenfeller’s accident in 2011.

‘By using this new lighting technology, Audi is setting yet another milestone at Le Mans,’ said Dr Ulrich Hackenberg, member of the management Board for technical development of Audi AG. ‘Laser light will also open up completely new possibilities for our production models in the future.

‘The new laser light is just one of numerous technical innovations featured by our new R18,’ said head of Audi Motorsport Dr Wolfgang Ullrich. ‘We’re not going to reveal any more than that at this early stage, as in 2014 we’re facing an extremely tough competition and a year full of challenges for Audi Sport.’

LE MANS 2014 17

TOYOTA TSO40 HYBRID

Agent K

Toyota is the only manufacturer to race with a double KERS in its Le Mans prototype, which boasts almost 1000bhp

By ANDREW COTTON

“The most efficient way to use energy is the fastest.

Our system is 6MJ, but our motor power is huge – it is more efficient and more strong than Porsche’s” 18 LE MANS 2014

T

he battle for supremacy at Le Mans began at the end of March as all the major LMP1 manufacturers announced which hybrid category they would run in. It was in France, at the World Endurance Championship pre-season test held at the Paul Ricard circuit, that the final pieces of the jigsaw came together and Toyota announced that it would run in the 6 megajoule (6MJ) category with a double KERS, front and rear. Immediately, Porsche scaled back its ambition and also entered the 6MJ category in its first year, while Audi made the decision back in November 2012 that it would run in the 2MJ category, and has stuck rigidly to that plan despite apparent flaws and the disadvantages imposed by the technical regulations.

It was something of a shock to realise that Toyota will not race with the maximum hybrid performance this season, although there are competitive advantages to running a larger system and there are aspects that could be upgraded next season. Using super-capacitors, a fast charge/recharge characteristic means it is more than capable of meeting the demands needed to run in the 8MJ class, and with front and rear KERS already built and tested in 2012 and refined in 2013, it seemed obvious.

However, the size of the battery and the weight distribution compromise that would need to be reached meant that Toyota dropped to 6MJ to cope with the decreased weight limit imposed on LMP1s this year.

‘The minimum weight was decreased from 915 to 870kg, so that impacted a lot,’ says team president Yoshiaki Kinoshita. ‘We designed our car to the same minimum weight. From 6MJ to 8MJ is a huge benefit because of the fuel allocation, but you cannot do the race with an overweighted car. Last year’s hybrid assistance was already 100kg, and this year we added a front motor. With the philosophy behind the regulations, a big hybrid system should have an incentive. It is a bit sad for us.’

For Hisatake Murata, Toyota’s hybrid project leader, the decision not to go for the full 8MJ category is not a disaster, and he considers that Audi’s system could also pose problems in race conditions this year. ‘It is an amateur point of view that 8MJ volume is huge,’ he says. ‘The 8MJ system is very good, but the 2MJ is also a good system.

‘We have already calculated that the most efficient way to use energy is the fastest. Our system is 6MJ, but our motor power is huge.

We have a lot of options to use the energy, so

that means we can use the energy in the most efficient way. The final conclusion is this year’s Le Mans, but I think our system is more efficient, more strong than Porsche’s system.

‘2MJ is the lightest way, and 8MJ of kinetic is a huge weight. But there are so many factors to consider, from the point of view of assisting the result, a system weight point of view, car weight point of view, from engine system weight point of view, engine thermal efficiency point of view, hybrid system point of view, hybrid assist performance point of view… there are many different systems, and the system design is very complicated. How to use the hybrid system is very complicated. It is a very complicated car, but from an engineer’s point of view it is very interesting.’

Although the super-capacitors could charge and discharge fast enough, the battery weight and overall system weight prevented Toyota from running in the 8MJ class.

The company did look at alternative plans, and even considered a turbocharged engine, but essentially carried over the normally aspirated engine from 2013 with increased capacity. Given that the rumoured budgets between Toyota and Porsche are four-to-one in Porsche’s favour, this was a predictable decision.

LE MANS 2014 19

TOYOTA TSO40 HYBRID

“Compared to last year, we are burning 25-30% less fuel, so to achieve this we’ve had to have a big step forward in efficiency”

The Toyota hybrid system features a Nisshinbo capacitator, and delivers 354kW/480PS

The floor of the Toyota TS040 does not offer up too many secrets.

Regulations around the front wheel area are more free than in 2013

‘A turbocharged petrol engine is not so efficient,’ says Murata. ‘We have to separate the diesel engine and petrol engine, and a petrol turbo engine is not so good.

‘We don’t use an MGU-H because my opinion is that if the engine drives the motor, it means that due to the engine back-pressure from the

front system. The DI engine needed a starter motor, but if we installed the rear motor, we could drop off the starter motor, and from the car design point of view, the front bulkhead is a very sensitive area for the aero guys.’

Toyota announced that the complete system could produce 1000PS – almost 1000bhp – for up to five seconds per release. This is spread between the engine, at 520PS, and the MGUs produce 480PS. However, the delivery of this power is across all four wheels, which reduces the dependency of a specialist tyre to cope with the necessary forces and reduces rear tyre consumption for the TS040 despite the reduction in size this year.

‘Compared to last year, we are burning 25-30 per cent less fuel, so to achieve this there is a big step forward in efficiency,’ says technical director Pascal Vasselon. ‘At the moment we have smaller tyres, but we have no concern of consistency.

We are not going to do two stints at Le Mans – Le Mans will be three or four stints. We don’t expect issues. We don’t expect a big change in terms of consistency.’

“Intellectually it is nice to do a full carbon gearbox, but in the end the weight saving is not that big” exhaust, the engine efficiency is sometimes down. We started to analyse such a system, but our conclusion was that the system efficiency was not so good, so we concentrated on MGU-K front and back. Our final conclusion is this year’s system. Two years ago we had already completed this year’s system, but the regulations didn’t allow us to run it, so we dropped off the 20 LE MANS 2014

Watching the cars deliver power out of slow corners, Porsche appears to deliver its power progressively, while the Toyota waits until it is straight, and then delivers all the power. For drivers, this is all part of the new driving style – the coasting into the corners, late and deep braking areas, and the fast change from brake to throttle which still favours the left foot braker.

Mapping it out

First test sessions this year are going to be taken up with calibrating the driver systems which will enable the drivers to save fuel, and – in Toyota’s case – the adjustable balance of power delivery from rear to front could also help them to drive the car.

‘Power delivery depends on corner condition, weather conditions or whatever,’ says Murata.

‘The driver can choose a map, very similar to the way he can choose the brake balance. Currently we are searching for the solution circuit by circuit and by road condition, and we are analysing.’

One of the major problems that comes with KERS is that it is brake specific. In 2013 at Spa, a hybrid failure saw the car pit moments later with overheating rear brakes. The car has run brakeby-wire for two years now to help the drivers to modulate the brakes between recuperation and braking events, but the small brakes would still overheat massively should the hybrid system fail. At Le Mans, Toyota was forced to change its braking system (see news story).

‘Our hybrid system, and our motor power is very big, so it means that if our motor stops, the brake disc temperatures increase,’ says Murata.

‘If we have a motor stop, we cannot continue to run. We have very intelligent failsafe system and motor reliability is very tough. If we have a system failure, it depends on the driver’s driving style, but using the same driving style they cannot continue for half a lap. One hard braking they can stop, but two or three hard braking? It’s very difficult to continue.’

Setting up the hybrid system for each circuit is not a small task, and the team is going to

The TS040 with one of two aero configurations in testing at Paul Ricard at the start of the season

have to work hard during free practice one at every race to make sure it has the most efficient system possible. Testing alone on track produces one set of fuel consumption figures (although even these change dramatically between the driving styles), but running in traffic, at different temperatures and altitudes, is going to produce even more different results. The computer needs to be programmed specifically at every race.

‘We have many different types of actuator: engine, front motor, rear motor, front brake, rear brake – so a five part actuator,’ says Murata.

‘What is the best way? It is very difficult to tell.

We calculate many parameters through a lot of simulation and tuning. Five actuators, high middle and low – it means a huge number of buttons. It is very complicated, but if a car’s condition is oversteer, we can easily change that to more oversteer or more understeer… we can choose.’

Power Unit

The rest of the power unit was also developed from the 2013 TS030, with the stroke increased slightly to give the normally aspirated engine a capacity of 3.7-litres. This was done to reduce revs and increase efficiency, although Toyota also toyed with the idea of going further, and producing a four-litre engine.

Ultimately, the Brake Specific Fuel Consumption – the exact amount of fuel in grams to produce horsepower – led them to the smaller of the two solutions. ‘We mainly changed the stroke, because of the length of the engine,’ confirmed Kinoshita. ‘We needed to keep the space for the hybrid system.’

Luckily for Toyota, the systems had already been extensively tested. Back in 2012, when the team was planning a full test season before Peugeot withdrew from racing, Toyota evaluated a front and rear Kinetic Energy Recovery System to see which was best. It was only allowed one at the time, and thanks to more freedom for the aerodynamicists, coupled with the ability to be able to harvest all the energy from the rear only, that was the system that was adopted.

Now, with a greater amount of energy that can be stored, and with Porsche and Audi running effectively four-wheel drive systems (the regulation limiting four-wheel drive to above 120km/h is now rescinded), Toyota had all the necessary data. ‘This year we are forced to have one motor [on the front axle] – we can’t have two because the FIA doesn’t want torque vectoring,’ says technical director Pascal Vasselon.

‘It is nothing special. The control system to handle it is more sophisticated, but it is just a good lightweight design. It is very similar to the one that we tested – it is smaller, lighter, and is one integrated unit.’

Toyota elected not to go for a carbon gearbox, having experimented with the technology in Formula 1 in 2009 and found its value to be limited. ‘It doesn’t make any sense to do a carbon gearbox because you have so much local loading introduction that you need a lot of inserts,’ says Vasselon. ‘Intellectually it is a nice exercise to do a full carbon gearbox, but in the end the weight saving is not that big. We went through that in F1 in 2009, when 80 per cent of our gearbox casing was carbon. It was not a bad choice at the time because we had a long bell housing. Carbon is very good with well

distributed loads, but as soon as you have local introduction points – like pick-up points – then you have to put inserts, and you end up in a complex exercise and the weight saving is not that big. We have some carbon, but only where it makes sense to have carbon.’

In testing

Toyota’s test programme has been extensive and has covered more than 25,000km with the two cars before the start of the season, but much of the development work had already been completed in simulation before the car hit the track. Using TMG’s extensive facilities in Cologne, the car was then extensively wind tunnel tested.

This year, the cars are narrower and lighter as teams battle to save 30 per cent of fuel compared to 2013, while still maintaining the fastest lap times. Porsche’s simulation has shown that the new cars should be capable of producing sub-3m20s laps, although Toyota believes that it will be comfortably in the 3m20s.

The narrow layout creates engineering issues, although much of the width reduction comes from the tyres, leaving the aerodynamic principles much the same as in 2013. ‘It is a clean sheet of paper design,’ says chief aerodynamicist John Litjens. ‘With the new powertrain data that you have, you still have to establish the track efficiency that you need to achieve, so with the simulations we had to start from scratch. The good thing is that the narrowing of the car is taken from the tyre width, so the flow through the monocoque doesn’t change that much.

The cockpit at the rear stays high for longer but there is not much more than that.’

LE MANS 2014 21

TOYOTA TSO40 HYBRID

The front motor has long since been developed – the original plan was to run it during the 2012 season

TOYOTA’S HYBRID HISTORY Back in 2006, Toyota first embarked on the development of a racing hybrid system. Production hybrid cars run most efficiently in the city, where the cars stop and go repeatedly, but the fuel efficiency drops during the high speed running. During a race, cars constantly undergo hard braking, which would create a large amount of energy for hybrid cars. So, gaining expertise in racing would eventually lead to developing a mass production hybrid system which is highly efficient at any speed range.

In 2006, Toyota participated in the Tokachi 24 Hours using a new hybrid road car, the Lexus GS450h,

which featured experimental capacitor technology.

That was an early test for this potentially useful energy storage system, which can quickly recover and release energy. During the race, in the northern part of Japan, the team collected various data, focusing on understanding how a hybrid system behaves in race conditions. They tried different driving modes and confirmed a 5-10 per cent improvement on fuel efficiency.

The development team was back in the Tokachi 24 Hours again in 2007. The previous year’s car had a system that was based on a mass production hybrid

system, but this year’s hybrid system was specially made for the event.

The base car was a Supra that was competing in SUPER GT GT500. A Motor Generator Unit (MGU) and a capacitor were installed to assist the Supra’s naturally-aspirated V8 4.5-litre engine.

The predominant feature of the car was a fourwheel regenerative system, with additional high power MGU at the rear and in-wheel motors at the front. The extra MGU on the rear was to regenerate the energy efficiently under braking. The Supra HV-R proved a 10 per cent energy efficiency improvement, compared to the car without the hybrid system, during the 3136km 24-hour race in which it achieved overall victory.

The victory confirmed that development of the racing hybrid system was moving in the right direction. But at Le Mans, Audi was winning with a diesel engine. To beat the champion at Le Mans, Toyota had to fill the energy efficiency gap between diesel engine and petrol engine first. And then it was necessary to reduce the weight of the hybrid system to improve the performance of the car. According to Toyota’s initial calculations, a hybrid system capable of delivering the performance to win Le Mans would be likely to weigh around 600kg, but to actually have a realistic chance, the system needed to weigh less than 100kg.

THS-R DEVELOPMENT Toyota’s racing hybrid programme stepped up in 2007 with the Supra HVR GT. Yoshiaki Kinoshita started the project, development was handled by Hisatake Murata 22 LE MANS 2014

When Toyota introduced the TS030 HYBRID in WEC, the team had developed a hybrid system called THS-R (Toyota Hybrid System - Racing), which had

“At the front, if you compare the new regulations around the wheel area it is more open than before” The big changes come at the front, where the front system requires driveshafts to the wheels, the bulkhead needs to be changed to accommodate the single MGU, and the regulations around the front wheels at the floor have also changed. Where the air attaches to the front of the car, there have been some big areas of development, although Litjens was coy about the detail.

‘If you look back to 2012, you would have only one system, and one reason why we went for the rear only system was the aerodynamic decision,’ he says. ‘Now, we have different rules, we can use more MJ, and you have to adapt the kinematics slightly. If you start at the front, the air starts to flow on the car and is disturbed as little as possible by the driveshafts, and we try to condition the flow. There was quite a lot of work from aero to minimise the losses. The air continues further and around the wheel wake.

In that time, the floors were quite restricted, so we could do the front diffuser, a Le Mans splitter, and the high downforce splitter which

extends into the chassis. Now you have a lot more freedom, so there are changes there. In the front, if you compare the new regulations around the wheel area it is more open.’

The introduction of a winglet, similar to that used by Audi on the R15 and which was successfully appealed by Peugeot – leading to the R15 Plus – is back on all three manufacturers. The target for each is to maintain downforce while shedding drag, particularly with the new driving style that requires drivers to coast down the second half of the straights, and into corners. ‘It is more to do with efficiency than downforce,’ adds Litjens. ‘You cannot work on one area of the car because you might make a change and what happens behind it is important. You have to look from front to back – the complete package. You cannot work on one area, because you don’t know what happens behind it.’

Toyota will therefore go to Le Mans with an already tested package. From the moment that the car hit the track for the first time – in

January 2014 – it was reliable enough to begin meaningful testing immediately. More than 100 laps were completed with the car on day one, and since then the company has tested for more than 18,000km even before the first race at Silverstone. ‘You are always in between – this year it was difficult to carry over parts, because the regulations changed, and we had to change the weight,’ says Vasselon. ‘So carry over was not so much, but then you never throw away what you have done – it is always carry over and white sheet of paper. The engine is a base of last year. The way to do it, Porsche has a 4-cylinder which is the 8-cylinder of the Spyder cut in two.’

This is actually year two of Toyota’s planned racing programme. It stepped up from a test programme in 2012 after Peugeot withdrew.

The 2013 season was supposed to be a one-car entry, although the team ran two for much of the season. This year, a full two-car team was planned, and on previous form, this is Toyota’s best chance of beating Audi at Le Mans.

TECH SPEC 220kW Denso MGU in between the engine and gearbox. The electric energy regenerated during braking by the MGU was stored in a Nisshinbo super-capacitor installed on the passenger-side of the car. The capacitor was kept at operating temperature by a water-cooling system and controlled by a Denso inverter system mounted on top of the capacitor.

The weight of the hybrid system was less than Toyota had targeted. They were able to reduce the size and weight of the rear MGU without compromising on power, thanks to a reworking of the rotor magnet arrangement. This technology is expected to also downsize massproduction hybrid system without losing power.

At the start of development, Toyota was building a four-wheel regeneration system with an Aisin AW MGU installed at the front.

But a regulation change meant that four-wheel regeneration was no longer permitted and the power released in between two braking points was limited to 0.5MJ, down from the original 1MJ. Therefore, Toyota decided to focus on the rear MGU, which delivered the biggest performance gain.

A hybrid system is not all about electrical parts, as the engine is an integral part that can contribute to system downsizing and energy efficiency improvement. For example, of the energy required for driving a lap in the Le Mans 24 Hours, 95 per cent of the 13.629km at Circuit de la Sarthe is powered by the engine, with the MGU responsible for the remaining 5 per cent.

LIGHTER WEIGHT

Toyota TS040

The normally-aspirated 3.4-litre V8 petrol engine developed specially for the TS030 Hybrid weighed less than 100kg, like an F1 engine.

WEC prototypes use various materials to complete the installation of a powertrain. To reduce the weight of these items, the TS030 Hybrid adopted a full stress-mount structure, which received the input from rear suspension directly. The increased stress means more strain on the parts, but Toyota was able to add 10,000km to the system’s durability through careful tests and development.

Regenerative cooperation brake technology is essential to a hybrid system, which efficiently retrieves kinetic energy by managing conventional pneumatic braking and regenerative braking, depending on the driving situation. In a racing environment, high precision is required from the system. Improving the precision to match 0.01-second gear changes, Toyota was able to achieve both efficiency and drivability.

THS-R for the 2013 TS030 Hybrid was basically the same as the 2012 system – the concept remained the same. The energy regenerated by the hybrid system is transformed into power performance. The concept of the development was to increase the power for a long period without interruption. Compared to the 2012 specification, precision of control – as well as efficiency – was improved to achieve better vehicle dynamics.

Category: Le Mans Prototype (LMP1) Gearbox: transverse with seven gears sequential Gearbox casing: aluminium Clutch: ZF-supplied Multidisc differential viscous mechanical locking differential Suspension: independent front and rear double wishbone, pushrod-system Springs torsion bars Anti-roll bars front and rear Brakes: dual circuit hydraulic braking system, mono-block light-alloy brake calipers front and rear Discs: ventilated front and rear in carbon Wheel rims: magnesium forged wheels Tyres: Michelin radial Front Tyre: size 31/71-18 Rear Tyre: size 31/71-18 Dimensions: Length: 4650mm Width: 1900mm Height: 1050mm Powertrain: Toyota Hybrid System: racing (THS-R) Engine: 90-deg V8 normally aspirated engine Valves: 4 Engine capacity: 3.7 litre Fuel: petrol Max power: 382kW/520ps, Lubricants: Total Hybrid power: front and rear 354kW/480ps Capacitor: Nisshinbo Front hybrid motor: Aisin AW Rear hybrid motor: Denso Front Inverter: Aisin AWRear Inverter: Denso Overall

LE MANS 2014 23

PORSCHE 919 HYBRID

Porsche back to the big time Stuttgart manufacturer unveils the technical details behind its ambitious 919 Hybrid, and explains what went wrong in testing

By ANDREW COTTON

24 LE MANS 2014

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orsche’s 919 Hybrid started testing in June 2013, but from the moment the car hit the track, it was hindered by an engine vibration problem that, due to the long lead-time of the replacement parts, delayed performance and endurance testing until the new year.

It was a setback that has caused problems for a team that hasn’t raced in the top class since 1998. From the moment that Porsche first decided that it would return to Le Mans with its own team, excitement has been growing.

More than 145 engineers are now installed at the Weissach facility near Stuttgart, work on a brand new wind tunnel is almost complete, and the learning process surrounding performance hybrids, started with the 918 hybrid road car and continued in the 919 racecar, is well under way. In fact, the team say, the hybrid element is the least troublesome bit of the new car.

The drive system of the new LMP1 racecar is based on a four-cylinder petrol engine that is as compact as it is lightweight. It is a 2.0-litre, V4 configuration with direct injection and a single turbo. Powering the battery is an electric motor, which is powered by the exhaust gas stream, and a kinetic energy recovery system that is linked to a similar system used on the 918 road car. Energy is stored in water-cooled lithium-ion battery packs.

First steps

The monocoque was finalised at the end of 2012 to meet with the company’s schedule of rolling out the car in June, announced just before the Le Mans 24 hours. This meant that the front suspension concept was designed early, and although the team initially claimed to have opted for coil springs, it has now admitted misinformation was responsible for that. Instead, it has an hydraulic interlinked suspension front and rear, which it tried to patent in Korea but the patent was rejected. Porsche’s Technical Director Alex Hitzinger says now that this was probably an old design, although this could be further misinformation.

The suspension linkage is not a major piece of news other than it was the link between front and back that was susceptible to the vibration caused by the engine difficulties in the early part of testing.

The car has been designed to be as efficient as possible, with a low frontal area, but still meeting the new visibility requirements of the regulations. The huge blind spots in the 2013 cars have been reduced significantly this year, just as teams are seeking to reduce drag. The Porsche therefore features a raised section in the roof, designed to give the drivers more height in the cockpit. ‘The bubble in the roof was not an afterthought, that was the result of being very aggressive in terms of frontal area,’ says Hitzinger. ‘You have clear templates which you have to respect in terms of cockpit internal LE MANS 2014 25

PORSCHE 919 HYBRID

Top: highlighting the MGU-K (front) and MGU-H (rear) on the 919 Hybrid, and how they connect to the li-ion battery. The front generator is operated as a single electric motor and drives the front wheels via a differential. This gives the car a temporary all-wheel drive system Above: the aggressive aerodynamic solutions at the front led to a bulge in the roof to meet with new cockpit regulations

volume and visibility templates, and you want to wrap around these templates. It is purely aerodynamic driven.’

In testing, the car ran an interim aero package and contests the World Endurance Championship in a completely different configuration. At the Le Mans test, the team ran flexible rear bodywork, but the team claimed that this was resolved for the race. ‘The changes are in aerodynamics and a little bit of the suspension, and after this it is finished,’ says project leader Fritz Enzinger. ‘It is important that we have more kilometres and more mileage.

It is a normal step-by-step change, targeting more downforce. We then have a freeze in specification for Le Mans. At Le Mans, where 26 LE MANS 2014

efficiency is the key to success, the kit is low dowforce, and at the opening races of the WEC at Silverstone and Spa races, Porsche paid for having a single kit.

Bad vibes

Almost from the first shakedown test at the Weissach facility, Porsche realised that there was a significant vibration problem with the V4 layout, and Hitzinger immediately demanded an extensive revision, which took almost six months to put into place and deliver. The new engine was installed into the car in time for a test late in December, at Portimão in Portugal, and new driver Mark Webber put 600km on to the car first time out. The team

later moved to Bahrain, and started putting race distances on to the engine.

‘We had vibration issue caused by the engine configuration,’ says Hitzinger. ‘We changed the engine configuration and reduced the vibration level a lot by changing the firing order.

Changing the firing order means a new crankshaft and camshafts, and new calibration because of the gas exchange changes. It was a big thing. We discovered the problem at the rollout. For me it was quite clear at the beginning that this was going to be a problem that would otherwise be very difficult to solve. I decided very quickly because it is such a big change that it takes a long time to implement it, but if you let it drag on before

Above: Porsche targeted the full 8MJ of energy recovery through its batteries, provided by A123 and delivered through the KERS on the front axle, but will race in 2014 with 6MJ Left: vibration problems with the V4 engine were identified early, but a long lead time for replacement parts – including an all-new crankshaft – meant a six month delay before performance testing could begin

you try to solve it, you could be in trouble later on. We saw the problem, and we acted decisively.’

The vibration issue caused major problems, not only for the interlinked suspension, but for components that were shaken off, and it led to drivers registering false readings too! ‘The driver uses certain inputs from the car in terms of feeling, through the steering for example, and through that gets the feeling for the car,’ says Hitzinger. ‘The vibrations clearly masked a lot of the input into the body. The feeling for the drivers was very different than what it would normally be.

We felt that there were issues on the suspension side in terms of yaw behaviour and so on.

The driver feels a lot, and if he doesn’t have that, and relies on the steering, the car feels totally different.’

While Audi and Toyota have increased capacity for their engines, Porsche has opted for a small two-litre, four cylinder engine which helps with structural rigidity and offers the packaging and capacity that Porsche needs to fit around the large batteries. ‘From a thermodynamic point of view, you want a certain ratio between air and volume in the combustion chamber and that leads you towards a smaller number of cylinders at a given capacity,’ adds Hitzinger. ‘With a four cylinder V configuration, you can nicely install it in the car as a structural component.’

Such a short engine has left the team with a transmission casing on which the rear suspension hangs that is almost a third of the car’s length. Although this is not ideal, the team says that it is almost as stiff as a longer engine.

Economy drive

‘Fuel is like gold dust now, and you need to showcase the best way to conserve it,’ said Porsche driver Mark Webber at the launch of the 919 Hybrid in March. The 30 per cent reduction in fuel consumption while retaining the speeds and distances covered last year, can only be achieved by re-using the energy otherwise wasted through exhaust gases, or kinetic energy expended under braking.

LE MANS 2014 27

PORSCHE 919 HYBRID

Porsche targeted the full 8MJ of energy recovery through its batteries, provided by A123 Systems and delivered through the KERS on the front axle, and the electric motor that is linked to the exhaust gas stream. However, cooling issues meant that achieving the full capacity was a tall order, and once Toyota decided on 6MJ, Porsche followed suit.

‘We have a lot of simulation and we have decided on this, but maybe in one month it will be different,’ he says. ‘Everything is new, we have

a lot of information, but technical decisions regarding what we can do, are due to be evaluated at the Sebring test [in March], and then we will have more information to work with.’

The decision to go for batteries as a storage system was a relatively simple one, says Hitzinger. While the Nissan ZEOD will require its batteries to power the car throughout the lap on a single charge, Porsche’s requirements are very different. ‘I think it was the smallest compromise to go with batteries,’ says Hitzinger.

‘It is the best compromise between energy and power density. It gives you more flexibility in terms of strategy and A123 technology is, in my opinion the best out there, and we are lucky to have them. We are exclusive in LMP1 and it is a very good thing for us. I think it is a lighter solution than the others. You size it according to how much power and energy you need, and how safe you want to be. You cannot compare like for like [with Audi and Toyota] because you don’t know what the others have done. Our investigations concluded that this would be the lightest solution for our application and our assumptions.’

For the rear ERS, the electric energy is not used as an anti-turbo-lag as, says Hitzinger, that is not as efficient as using it totally for charging the battery between braking phases.

‘It’s another turbine which drives an electric generator, so as soon as there is more exhaust energy than required for the turbocharger, then that surplus exhaust gas flows through the additional turbine. It’s nothing to do with anti-lag. Flowing electric energy from the exhaust energy recovery system to the front is possible, or direct it to the battery.’

With a tightly-packaged engine sitting low in the chassis, and with the exhaust, turbo and ERS above it, cooling is an issue. ‘It is clearly a big challenge to cool everything down, but you just have to sort it out,’ says Hitzinger.

Brake system

Porsche was coy about its braking system, refusing to confirm or deny that it was a brake-by-wire system, although this seems

“The braking system eliminated the effects of energy recuperation so the driver doesn’t get disturbed through the influence of the front KERS” DRIVER’S VIEW

P

orsche asked Mark Webber to join the testing programme in 2013, but the Australian felt that he wanted one more year in Formula 1 before making the switch back to sportscar racing.

When he did, at the end of the 2013 season, he brought with him 14 years of Formula 1 experience, and a return to the type of racing in which he effectively made his name with Mercedes. ‘First of all it is a massive programme, a serious effort from Porsche,’ said Webber at the launch of the car at the Geneva Show in March. ‘The car is massively complex. It is very advanced in lots of areas, but we need to gain experience.

It is early days for us.

28 LE MANS 2014

‘I particularly enjoy being back in the endurance element, I always enjoyed that when I was with Mercedes. I like driving at night, and the driver changes. The fourwheel drive is quite cool, so that’s a nice feeling.’

The development of energy recovery systems is a new way of going racing, one that will require a new style of driving, and for drivers to actually accept orders from the pit wall to manage the amount of energy that they have available to them.

‘We are on the curve at the moment where manufacturers are learning,’ says Webber. ‘They know that there is lots of fruit on the trees in the distance, but you can’t get

there in a couple of months. You have to go through the superadvanced technology, the packaging, and it is how big your balls are, how big do you want to go with certain things, knowing that it will benefit you in the future.

‘These guys we know are worldclass in the way that they will tackle things, but we have to get the balancing act right in terms of how much ambition you have, what we will learn in the future and how much we run learn now.

‘In terms of driving style, it is good that it is so far away from what I had. I haven’t used my right foot for braking for 14 years, and I am using it again. The car is a bit heavier,

has less downforce than an F1 car, but there are sections where the power is very good.

‘With the development pace, what I get used to in February is not what we are going to have at Le Mans. The stuff is coming through quite quickly.

We know that it is in our best interests to stick to the regs in terms of the fuel burn. That is the way all motorsport is going at the top end. This category and Formula 1 is in the slot for new automotive technology. Fuel is like gold dust now, and you need to showcase the best way to conserve it and the driver has to be in the loop for that. You can’t have the driver out of the loop in terms of understanding that philosophy.’

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PORSCHE 919 HYBRID TECH SPEC Porsche 919 Hybrid Class: Le Mans Prototype (LMP) 1 Monocoque: composite fibre construction made of carbon fibres with a honeycomb aluminium core Engine: V4 engine with turbocharging Engine management: Bosch MS5.6 Engine lubrication: dry-sump lubrication Displacement: 2.0 litre Power: >370 kW (>500hp) Hybrid system Accumulator type: lithium-ion battery, EGU on front axle EGU power: >250hp On-board system battery: Lithium-ion Drive and power transmission Drive type: rear-wheel drive, all-wheel drive via KERS on the front axle Clutch: CFR Transmission: sequential, hydraulically activated seven-speed racing transmission Differential: rear differential lock Transmission housing: hybrid construction in CFRP with titanium inserts and cast aluminium housing Drive shafts: constant velocity sliding tripod universal joints

Porsche’s new LMP1 entry marks a welcome return to the class after a 16-year absence, following victory in 1998

likely as Formula 1 teams are deploying similar technology due to the heat rejection in critical areas around the wheels.

The front brake system is a basic Kinetic Energy Recovery system and was a logical choice for energy recovery due to the amount of force on the front axle under braking. ‘The front axle has the most potential for recouping kinetic energy and it has traction advantages

“The car is massively complex. It is very advanced in lots of areas, but we need to gain experience.

It is early days for us” too,’ says Hitzinger. ‘If you have the choice, you will always go for the front axle. Basically, you have an MGU, and the energy has to go through a differential to the front axle to drive the two wheels. It is an MGU and a gearbox, which changes the speeds and split it through a diff. They are fixed ratios in the gearbox.

‘The braking system basically eliminates the effects of the recuperation so that the driver 30 LE MANS 2014

doesn’t get disturbed through the influence of the front KERS. It is a development with the drivers because some influences are more disturbing than others.’

To deliver 8MJ over the course of a lap sounds relatively simple, but this is more than double what was permitted in 2013, and management systems needed to make both work together are complicated enough, without the need to strictly regulate the amount of fuel a car may be able to use over each lap. At Le Mans, the engine is driven at full load for 75 per cent of the 13.65km lap.

The amount of fuel that a car may use over an average of three laps is closely governed, and monitored by a fuel flow sensor that is now accurate to 0.2 per cent, although the recent problems highlighted

by Red Bull and Renault have cast doubts on the system. Porsche has practised changing the sensors in the pit stop as required, as in sports car racing the sensors are mounted externally to the fuel tank. Teams have experienced ‘drift’ in the readings, although these are not necessarily the fault of the sensor.

‘At this stage, no one has run a car for 24 hours,’ said the ACO general manager Vincent Beaumesnil ahead of the first race of the season, and months before the Le Mans 24 hours. ‘You can change it in a short time in a pit stop, and there are two fuel flow meters on the car, and three on the diesel. If one is starting

Chassis, steering and brakes Chassis: front and rear multi-link pushrod independent wheel suspension with adjustable shock absorbers Steering: hydraulically-assisted rack-and-pinion steering system Brakes: hydraulic dual-circuit brake system, light-alloy monobloc brake calipers, internally ventilated carbon fibre rear and front brake discs Rims: forged magnesium wheels Tyres: Michelin radial, front and rear: 360/710-18 Dimensions and weight Height: 1050mm Width: 1900mm Length: 4650mm Minimum weight: 870kg Tank capacity: 66.9 litres

to go, we have another one, and we can ask them to change at the next pit stop. If the sensor doesn’t work, we discussed the possibility some months ago, but now I have no more issue with that. Even if the telemetry doesn’t work, you can collect the data through the transponders.’

However, Porsche does not believe that the system will work properly. ‘It hasn’t held us back because we did not make our development dependent on it, but there is still no robust solution in place,’ says Hitzinger. ‘The FIA is still very hopeful that the latest spec will work and will be reliable, but that is not proven yet. We optimise how they are mounted to give them the easiest possible life, but right now we don’t know if it is all going to be robust. We should know at the end of March.’

The management of fuel allowance over an average of three laps is difficult enough when a car is running alone on the test track, but in race traffic, behind a safety car, and in different weather conditions, temperatures and altitudes, it will all be a completely different set of calculations.

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PORSCHE 991 UPDATE

Old dog, new tricks Porsche turned a swan into an ugly duckling with its 991 in 2013. But, for their 2014 programme, it now boasts a comprehensive update kit

By ANDREW COTTON

P

orsche’s 991 may have won at Le Mans in 2013, but it struggled everywhere else. So, for 2014, the manufacturer introduced an upgrade kit with a difference. The story of Porsche’s GTE has been an interesting one. From the first test at Sebring in March, 2013, to the first race, at Silverstone in April, it turned from a swan into an ugly duckling.

Fuelled by optimism following that test in Florida, Silverstone was something of a shock for the team and drivers. At Spa, it got even worse as high rear tyre wear compared unfavourably to the Aston Martin, which double stinted its tyres and was still fast.

Something happened to the car, and team members were coy about discussing it. ‘That was our test car, and for the racecar there were some minor changes for homologation. We think that was the problem,’ says lead driver, and engineer Marc Lieb. ‘There were some small issues, changes from departments that we thought wouldn’t be a big influence on the car, but obviously they were.

‘It was a surprise for us because we were optimistic in the winter. At the end of last year we had some good tests, we were happy with the consistency of the car, we had one really good test at Sebring where we thought this was the way to go, but it wasn’t.’

Amid rumours of sandbagging and short-filling the tanks during the Silverstone 6-hours and at Spa, Porsche was given a larger air restrictor for Le Mans, and was able to keep pace with, although not beat on speed alone, the Aston Martin Vantage.

Rivals claimed that this highlighted the sandbagging, but for the rest of the year, the Porsches struggled, up to the point of the introduction of the new car at the final round in Bahrain.

There, the update kit was introduced, and it caught Porsche’s rivals by surprise. It was not the speed that caught them off-guard – the two 991s qualified first and second – more the pace of development.

Questions asked

Under the regulations, a manufacturer may update a new car once within the first two years, but has to race that update during the car’s first season. The final round of the World Endurance Championship in Bahrain saw Porsche turn up with a host of changes that led some to question whether or not this was a completely new car.

‘We changed the aerodynamics for next year’s car, with the aero balance more to the rear, and that hopefully helps the drivers

to be not always just on the edge and have good lap times for one hour or one-and-a-half hours,’ said Marco Ujhasi, project leader for the 991 RSR. ‘For the low speed stuff there are also some changes. We increased the chassis stiffness and changed the kinematics, so the car is more driveable than the 2013 cars.’

Porsche has made the car stiffer from front to back, and has made changes to the roll cage, reducing the diameter of the tubes, and the fixing to the chassis. Porsche has also changed the fuelling system, the aero balance including a wider rear wing and a wider rear wheel – both of which were on extra waivers agreed by all other GTE competitors – and a slight modification to the engine cooling system.

‘The chassis was changed for the stiffness,’ says Ujhasi. ‘We wanted to have a more consistent stiffness from front to rear and also we wanted to improve the durability.

For the aero balance, we have a shape on the front bumper that can compare to the Le Mans aero, so there’s less downforce at the front, more at the rear due to the wider wing.’

The aero package is more aligned with that raced at Le Mans, but the balance suits the car much better, and takes the handling and tyre degradation back to levels previously seen on the test car.

LE MANS 2014 33

PORSCHE 991 UPDATE

‘We increased the chassis stiffness and changed the kinematics, so the car is more driveable’

The front bumper more closely resembles the aero kit that the manufacturer raced at Le Mans last June, as Porsche sought better aero balance

The car’s new aero balance meant a change to the front and rear suspension kinematics, although Porsche has denied that the 2014 model has a new rear axle

New air intakes for the engine may have slightly increased power, but certainly not enough for engineers to start boasting

Wider wing and wider rims were crucial to managing the rear tyre wear with the 991.

Porsche required waivers in both cases

‘It wasn’t working with the aerodynamics,’ says Porsche’s motorsport director Hartmut Kristen of the ‘old’ 991. ‘You have to get everything properly in balance, not just in theory but in reality to make it work. These are the main points that we had to address to run the weight balance as it was supposed to be.

‘We slightly changed the aero balance in a way that didn’t work properly for the early 2013 car as it was raced. We got one more waiver for the width of the rear wing because we had the smallest rear wing compared to the other cars and the still existing technical regulations – the rear wing is linked to a percentage of the standard car. This is crazy when you compare that to the racecar that is within a few centimetres, so we got an additional waiver there.

34 LE MANS 2014

‘We made a change to the fuel cell, because there we had some problems with the refuelling from time to time, so that had to be homologated. But that is mainly it.

The more parts you homologate, the more parts you have to change. There are a few suspension parts with modifications, but nothing completely new, a new concept or anything like that – just adjustments.

‘We still use the 997 engine, but in the engine there are a few details optimised, a small change to the air intake and the filters.’ The engine, taken from the 997, lacks the direct injection option enjoyed

by Ferrari, and even by the 991 road car.

As detailed in RCE V23N7, there is no appetite to develop a new engine with new regulations that were supposed

to come into force in 2016, although a breakdown in the convergence talks late in May have negated the need to wait. Chassis convergence is still an option, but engines are likely to run as they are today in 2016.

The 991 has a new, stiffer chassis, a new roll cage, a wider rear wing and wider rear rims (although not wider rear tyres), modifications to the suspension and a change to the fuel cell.

This was a huge effort by the company, which was able to sell the cars to customers in time to compete in the 2014 season.

This year, for the first time, Porsche is fielding two factory teams in the same championship. This is an exciting time for the company’s racing department, and clearly there is huge commitment to on-track success.

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CORVETTE C7R

Stingray’s

big brother Corvette Racing used the 2014 Daytona 24 hours to debut the lighter and stiffer follow-up to the award-winning C6R

By ANDREW COTTON

“They started with an aluminium chassis. It is 90lbs lighter, and 40 per cent stiffer.”

36 LE MANS 2014

J

ust about every new car that is launched emerges with fanfares boasting the words ‘lighter’, ‘stiffer’ or ‘more efficient’, but in the case of Corvette’s new C7R – which debuted at the Daytona 24 hours at the end of January – the new chassis design has led to renewed optimism in the camp.

Designed and built by Pratt & Miller Racing, with close links to the production C7 Stingray, the car is the latest in a line that has delivered nine Manufacturers’ and Teams’ titles, seven wins at Le Mans from 10 starts, and eight drivers’ championships in the categories in which it has run. The drivers say that the car is even better than the C6R, and were able

to monitor the difference as soon as they jumped behind the wheel.

‘What they have done is incorporate high pressure castings in the critical bends rather than hydroform rail,’ says programme manager Doug Fehan. ‘Then they bond the hydroform rail to the high-pressure casting. It is lighter and way stronger. They started with an aluminium chassis.’

In fact, it is 90lbs lighter, and 40 per cent stiffer, as Fehan explains. ‘The beauty of hydroforming is that you take a tube, you bend it into a shape, insert it into a dye, plug the end of it and then load it with water pressure that expands the tube into the shape of the dye. That is how the frame rail

was made. At the time, the chassis was the largest hydroform rail in the world. Rather than forming a bend, it maintained uniform thickness because you were blowing it up. You didn’t have thin spots, thick spots, heavy spots or weak spots, and the strength is incredible.

‘When you want to address the high stress areas, the bends, the team said that there was new technology in this high pressure casting which is a super-thin wall that can be webbed.

And it is amazing stuff. Each one of those bends is a high pressure casting. Then the rocker rail is still the hydroform rail – it is just welded to that upright. Each of these critical areas has the high pressure casting in it. That is where the weight is saved, and the increase in strength occurred. When the drivers got in they recognised it straight away.’

Drivers reported that the ride over the kerbs was markedly improved over the C6R following back-to-back testing. There were problems in qualifying at Daytona associated with a new car, but race pace was much better.

The team targeted a 1-1.5 per cent increase in overall performance compared to the C6R.

LE MANS 2014 37

CORVETTE C7R

The aluminum frame structure of the Stingray, with ‘greater torsional rigidity to improve ride and handling’

The production Stingray features a 6.2-litre V8 engine, while the C7R has the 5.5-litre which ran in the C6R

The C7R features a new cradle at the front and the rear for the engine and the gearbox. They are more robust 38 LE MANS 2014

The production Stingray has a 6.2-litre V8 engine and features variable valve timing (VVT) and direct injection. Working to reduce the capacity and take away the VVT technology was deemed to be too time consuming, too expensive and something that would raise the cost of the customer engine beyond acceptable limits, and so the team successfully sought to have the 5.5-litre engine of the C6R accepted into the new car, although it is upgraded to have direct injection.

‘The new technology on the production engine – aside from direct injection – is the variable valve timing, which is an amazing performance advantage,’ says Fehan. ‘It is not allowed in our series, so when you equated the cost of taking a brand new engine, developing it in a 5.5-litre configuration, and the elimination of VVT, you had a huge escalation in costs for no increase in performance. You’re spending money and wasting time for essentially what we have here.

‘And, by the way, the sanctioning body is fully familiar and comfortable with this powerplant, and should any additional competitors want to come along and use it, we have this engine extended to almost 60 hours of running at about $120,000 initial cost, including DI, which is something that they implored the manufacturers to do, but no one paid any attention to it but us. There was no sense in rebuilding and retuning this thing, and that was the philosophy on both sides of the pond. This is an identical C6 engine, with the exception of the added DI.’ The team already had experience running direct injection on its GT1 in 2009. The production engine already had a DI port and so it was an easy introduction into the race unit.

Clear correlation

There is a time-worn mantra at GM racing that a better racecar leads to a better road car, and that a better road car in turn leads to a better racecar. In the case of the C7R, the correlation between production and race models is clear.

The front splitter, the side skirts and the air intakes are clearly taken from the road car and developed for racing, while the racecar influence on airflow through the production car has led to a tilted front radiator and air extracted through the engine cover.

‘When you look at the cooling ahead of the rear wheels, it is the same on both cars,’ says Fehan. The intake in the racecar splits the air and directs half towards cooling the rear brakes, and half towards the cooling of the differential.

‘The rules control the bottom of the car so there is nothing different there. The production car is two inches wider at the front and three inches wider at the rear than the standard production Stingray, but in doing so, it gives them a wider area to take the air out. That is something that we learned in the wind tunnel and CFD and that works with the side skirts.’

The rear wing is wider than the C6R, and the team found that airflow to the wing is disturbed by the intakes behind the doors that feed air to the diff on the production car. The racecar therefore has lost the intakes, and has a new lip on the rear deck, replacing the full wing on the production car.

‘When we add the rear wing, the air intake disturbs the air over it,’ says Fehan. ‘We run a different spoiler because it is a drag issue, so we have a waiver for it.’

Packaging under the skin has been improved following the change to the chassis

and the weight saving that came with it. The team was able to design a new cradle for the engine and at the rear of the car that is stronger, and slightly heavier than its predecessor.

‘The philosophy of the suspension is carried over from the C6R, the mounting points are from the C6R, and they all have a little bit of a different construction and configuration, both in weight and in terms of performance,’ says Fehan. ‘There are changes in geometry at both the front and rear. The gearbox is essentially a carry over gearbox, although we have worked with Xtrac in developing pneumatically

controlled adjustments to reduce the amount of time necessary to make changes in the way the drive operates, so that will be good.

‘It is the same paddle shift as we ran last year, but aside from the engine and gearbox there is not really a common part with the old car. We have new uprights that are lighter, run cooler and are stronger.’

The team added paddle shifting to the C6R, and carried over the same system to the C7R, so from the 90lbs saving brought on the chassis, the overall weight of the car is only 25lbs lighter than its predecessor.

DRIVER’S VIEW

A

t the Sebring 12 hours in 2013, the Corvette team revealed a new device that is capable of informing the drivers of a car that is closing, at what rate it is closing, and which side the faster car will pass.

The system runs on a custom Linux machine with an Intel Core i3 CPU and uses a rear-facing radar sensor that is capable of tracking up to 32 objects while working in tandem with the camera. Different colours and symbols are displayed on the rear view screen, which allows the driver to easily see racecars that are behind, how close they are, their closing speeds, and even the approaching vehicle’s racing class.

It was developed in conjunction with the drivers, and the team admits that it still needs refinement. Driver Oliver Gavin admitted that there are so many flashing lights it the cockpit that the driver learns to tune out many of them, but that this system is one of the most useful.

Blind spot ‘There have been times that we have been very close to an LMP car and not been sure exactly where it is,’ says Gavin. ‘This system allows us to look very quickly at a screen and see exactly where it has gone, as it will be in our blind spot. You can tell on the screen people gaining on you. In the rain and at night, you have lights behind you and you don’t know how far back they are, so this can give you an idea, and help you to work out if they are going to get you before the next corner.

‘There are lots of different systems, and it does get to be an overload, but it is good. It needs refining, but it works for us, and I think you will see a lot of teams going in this direction. It keeps us safer on the track particularly at a place like Le Mans which is so big that you cannot get enough spotters,

The new Corvette system features a Bosch radar sensor that can track up to 32 objects while working in tandem with a camera

cameras and so on. For that reason I think it allows the driver to be a little more self-sufficient.

‘It works on the screen but we are talking about how it will communicate with us. We’re talking about having a buzzer in the helmet to work with the lights, and we will keep developing it.’

The system was inspired by the accidents that hit the Audi team at Le Mans in 2011, which were clearly directly caused by a lack of visibility.

Allan McNish came from two cars behind and was hit by a Ferrari, which was unaware that he was there, while Mike Rockenfeller flashed another Ferrari at night. One of the criticisms of the Audi light system was that it was so bright, there was no depth of field, and so the driver did not know how far back, or how close, the Audi R18 was.

‘When we watched the Audi incidents that occurred we just thought there might be a better way,’ said programme manager

Doug Fehan. ‘We were fascinated by developments in the industry that lent themselves to developing something that has not been developed before.

The aviation industry has used this technology forever, and if you look at the advancements in GPS and things like that, we said, “wouldn’t it be great if we had a screen and the guy could see what was going on around him?”

Radar and camera ‘What was really important was identifying the speed of the cars around him. We did a couple of runs at that several years ago, and it was something of a success. So three years ago we dedicated ourselves to finding something that could track multiple cars, allow you to determine speed differential, would allow you to determine positioning right or left, and closing distance so that the drivers at a glance can see exactly what is going on. It can discriminate cars that are

closing on you, that you are pulling away from and those that are travelling at the same speed.

‘It was designed by Pratt & Miller. It uses a Bosch base radar and we write all the algorithms around that sensor that the driver sees. We did some testing with it, and the first application was at Sebring.

‘We worked with the drivers to accomplish what we needed to accomplish without the drivers getting distracted. It is another set of eyes.

With the rear view camera you can see what is coming up and they were accustomed to using that, and this just gives more data with that same glance. You programme your brain to see that. If you see something green, you don’t need to worry. If it is yellow you see where you are on the racetrack and if it is red, you know you are going to get passed, and which side. You can adjust to it very quickly, and become dependent on it.’

LE MANS 2014 39

CORVETTE C7R

“The philosphy of the suspension is carried over from the C6R, but aside from the engine and gearbox, there aren’t any common parts” ‘There are always things that you want to do things that are going to add weight, so you are easily able to absorb that,’ says Fehan. ‘They were the production numbers. You do all your FEA on it, and are tempted to put in that extra bar in the roll cage that will increase stiffness just a little bit, but you hate to add the weight because it is high up. Here we didn’t have to do that.’

By regulation the GT cars have to run an air conditioning system, and the Pratt & Miller

team have taken the compressor from the Chevrolet Volt, which takes less than 1bhp to drive it, and mounted the whole system at the rear of the car. ‘We have developed a system that has a tremendous amount of absorption in it,’ says Fehan. ‘We are working to improve the condenser unit – that is the biggest struggle. If you look at the compressor as the heart of an AC unit, it is the condensing coil that is where the temperature drop occurs – that is where you have to make the transfer.

The team has used production parts to build the air con system at the rear, largely taken from the Chevrolet Volt

The C7R has a new side impact protection system, made from carbon Kevlar with an expanded honeycomb interior 40 LE MANS 2014

‘We have a new system coming that uses something a little bit different to this, and I am hoping that we have it tested and ready before Le Mans.’ The team also runs the latest Ole Buhl powerbox in the car.

The team has taken a pragmatic approach to safety in the C7R, refusing to run the narrow seat belts, or the adjustable seat that some of their competitors feature, but the biggest step in safety is the side impact protection system that was developed in conjunction with the Wayne State University, a premier research institution in Detroit, Michigan.

The system is basically a box made out of carbon Kevlar with an expanded honeycomb interior that absorbs impact from foreign objects. ‘We built a roll cage, and the honeycomb aluminium is a purchasable material and has different crush rates,’ says Fehan. ‘We went through a major programme of crush testing to determine which would provide protection and absorption, without being rigid like a NASCAR bar, or just nothing.

‘We had an incident last year with Johnny O’Connell in the Cadillac, where something punctured the door. We don’t know what, but it went into the box. The Kevlar stopped it from penetrating. That is an added advantage. I have been through some tragedies with drivers and couldn’t do without it.’

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FERRARI F458 GT2

Fewer horses

more prancing Ferrari introduced the F458 for the 2011 season and it has proven to be phenomenally successful against established opposition. First run in REV21N6, Racecar Engineering talked to Michelotto about the development

By MARSHALL PRUETT

42 LE MANS 2014

“The 458 is a very good road car, so our job was easy”

W

ith two class wins at Le Mans and numerous championships in Europe and North America, Ferrari’s F430 racer took the fight for supremacy in the hotly contested GT2 category to its nemesis, Porsche.

Except for the brief period during the 1990s when Ferrari’s F40 GT-LM was considered a worthy contender on the GT racing scene, Porsche’s various production-based racecars owned the lower tiers of GT competition. That changed when the F430 moved to the forefront in 2008 and 2009.

The brief taste of glory was parried back

by Weissach in 2010, with 997 RSRs winning their class at Le Mans, while championships in

the ALMS and LMS drove the final nails into the F430’s coffin.

Ferrari had its nose bloodied, and had to respond with something special. Luigi Dindo, chief engineer for the F458 GTC programme at the factory racecar engineering concern Michelotto, says that with the F430 at the end of its development cycle, sweeping changes were saved for the new-for-2011 F458. Rather than carry over proven elements of the F430, every section of the F458 was treated with a brand new approach.

‘First of all, the 458 is a very good road car, so our job was easy,’ says Dindo. ‘The target was to improve each aspect of the 430. First, the V8 engine, which, because it is productionbased, uses direct injection to improve fuel consumption. And we tried to improve power and torque, because the new motor is 4.5-litres instead of the 4.0-litres of the 430. Also, at the end the target was to make everything lighter.

LE MANS 2014 43

FERRARI F458 So we tried as much as possible on the engine to reduce weight without making crazy things, because it is a GT class for customers, not a works team.’

Less power

The ACO’s move to slow the GT2 class for 2011 resulted in the F458’s bigger engine producing almost 100bhp less than its roadgoing counterpart – approximately 470bhp at 6250rpm, thanks to dual 28.3mm air

A heavier engine meant weight had to be saved in other areas to redress the balance. Hewland came up with a lighter six-speed sequential ’box with the added bonus of a lower centre of mass

44 LE MANS 2014

restrictors. Utilising four chain-driven cams and four valves per cylinder, the engine, code named F142, generates roughly 520Nm of torque at 5750rpm. Cast from aluminium, the dry-sumped F142 uses the lightweight metal almost exclusively, except for its steel connecting rods and forged steel crankshaft.

Dindo says the 4.5-litre motor has seen as much as a two per cent improvement in fuel economy with the use of direct injection, and that the 90-degree V8, fed from a 90-litre

fuel cell, was designed with the capability to swap between a variety of fuels, including E85 ethanol and E10, depending on the series the F458 competes in. ‘[Direct-injection] is not a big step because the primary goal at higher revs with the high-pressure pumps is to give some extra power, so it is between a 1.5 and two per cent improvement in race conditions,’ says Dindo.

‘Where you have open throttle, when you have a partial load, the difference is higher but also it depends on the circuit and how much the driver is on or off the throttle.’

While the F458 produces more power than the F430 it replaces, it carries extra weight compared to early versions of its predecessor, tipping the scales at the ACO’s 2011-mandated 1245kg which allows it to run larger tyres.

The need to shed weight and to optimise weight distribution led to the F458’s six-speed sequential Hewland gearbox receiving a lot of attention, as Dindo explains:

‘For the gearbox, we wanted a quicker shift mechanism, and Hewland was able to give us a lighter gearbox case and gear cluster. We also wanted a lower centre of mass on the gearbox, and we have been able to get it. It was also made stronger because of the increased torque of the engine.’

Looks familiar

The F458 looks similar in some ways to the F430 but, barring the cabin’s interior, the majority of the chassis, major systems and placement of the ancillaries have been re-worked. It would be a stretch to call the midengined two seater a completely new design, but the majority of the underpinnings and the body panels are different enough to stand out in a direct comparison.

‘We wanted to improve the suspension design with the same philosophy. Now there is a race suspension on the car with fabricated uprights and control arms, we no longer use

the production control arms of the road car. For the rest of the car, we did not try to change the major concepts, only to put the weight as far at the bottom and to make the car very light.’

Beyond the change in construction methods, the F458’s multi-link suspension underwent possibly the most radical re-design of any aspect on the car, with revised geometry and optimised c of g and polar moment of inertia. The move to wider 12.5 x 18in front wheels, adopted by most contenders in the category, also helped alter the F458’s balance, while the rear wheels are slightly wider too, at 13 x 18in. Both Michelin and Dunlop offer tyre options for the car and, while tyre sizes vary slightly between the French and British rubber up front, with Michelin’s 300/650-18 units offering a shorter sidewall than Dunlop’s 300/660-18 provide, both make a 310/710-18 for the rear. Controlling the wider fronts is aided by the F458’s electro-hydraulic power steering system.

Brembo brakes are used, with six-piston calipers and 380 x 35mm steel front discs, with four-piston, 332 x 32mm units at the rear leading to very different handling characteristics for the new car compared to its predecessor.

Aero changes

Aerodynamically, the F458 is considerably different to the F430. The latter manifested a number of aerodynamic add ons over the years, with a variety of flicks, dive planes and floor revisions used to keep pace with class development, but the car’s overall downforce levels was always a question mark. With the F458, many of the F430’s sleek and flowing lines have been replaced with more abrupt, rakish transitions, designed to produce more downforce from nose to tail. ‘We concentrated very much on the aerodynamics, trying to improve the already very good parameters of efficiency of the 430,’ says Dindo. ‘At the moment it’s a little bit more resistant than the 430 and so is slower on the straight, but we’re working on that side to match the speed of the

The whole suspension and chassis has been re-engineered, and attention has been paid to keeping weight as low as possible in the chassis

Gone are the production suspension components of the 430, in their place a purpose -designed race set up, with fabricated uprights and control arms LE MANS 2014 45

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Dynamic Engineering

FERRARI F458

The 458’s multi-link suspension underwent the most radical re-design of all, with revised geometry and optimised c of g and polar moment of inertia, making the new car an entirely different handling racecar to the 430 it replaces

430 at least. However, it has a little bit more downforce, which should make the car quicker in the slow and medium-speed circuits.

[The reason] why, at the moment, we are suffering in the high-speed circuits is being investigated, but we are working to get a new kit for Le Mans.’

Asked if Michelotto had quantified top speed issues as being more downforce or drag-related, Dindo confirmed his team will be looking for ways to carve as many excess pounds of drag off the F458 as possible: ‘I think the downforce is a little bit more than the 430, but it’s not the problem. The car is wider because of the bigger tyres, so we needed to get back some drag to compensate the wider front surface. So we work not to reduce the downforce but reducing the Cd.’ Engine cooling philosophies also changed radically between the F430 and F458, with the new car utilising much larger openings in the nose and an articulated radiator venting system designed into the bonnet. The F430’s wide, boxy front chassis section prevented the use of a large, central radiator, so two smaller units were adopted at the outer edges of the nose in front of the wheels, while an even smaller oil cooler was somewhat clumsily plumbed through the limited space under the bonnet.

With the F458, the front of the chassis was designed from the outset to reverse this trend, and makes use of a large, steeply inclined water radiator, while there are two smaller coolers in front of the wheels.

As well as presenting possibly the least appealing visual aspect of the F458, these

various openings also likely contribute to the excessive aerodynamic drag the car currently suffers from.

While most manufacturers go to great lengths to ensure bonnet venting directs as much air as possible around the cabin sides, the F458 sends a large volume of hot air from the water radiator straight over the greenhouse, adding to its drag issues.

The F458 follows the trend for 2011 of exposing as much of the outer portions of the front and rear wheels as the rules allow. After pushing the boundaries in this area last year the new car exploits the flow-through benefits as much as possible, helping to extract air from the diffuser.

Sebring for Risi Competizione, but in the race, mechanical and electrical gremlins plagued both the Risi team and the Extreme Speed Motorsports entries. Gianmaria Bruni set pole at the European LMS race at Paul Ricard, but the development has a long way to go.

Electronic switch

‘The problem is the car arrived very late. If it arrived two months earlier, we would be in better shape,’ said Dindo, who oversaw the first test of the car at the end of November. ‘In this condition, we are producing the car, we are racing and we are testing to improve reliability at the same time. For sure, the car is young and should be looked at like a young driver or young man starting his first days on the job.’

After years of patronising Italy’s famed racing electronics firm, Magnetti Marelli, the F458 has made the move to Bosch. ‘We made the biggest step forward compared to the 430, aside from the suspension, when we changed the electronics from Magnetti Marelli to Bosch Motorsport, because they had better software and better electronics. And also the electrical wiring has a power box, so it is a multiplexing system, which is common on racecars now. We wanted that on the 458.’

The Bosch MS5.1 system also provides a robust traction control system. Based on Corvette Racing’s similar switch for 2011, it has become the package of choice in GT racing.

The one limiting factor in the F458’s performances at the 12 Hours of Sebring stemmed from the late delivery of the initial batch of cars. Jaime Melo qualified fifth at

“The car should be looked at like a young driver starting his first days on the job”

Driving impressions

With all of the work that has been put into the F458 and the 20 cars Michelotto will build this year, and despite the car being at the very beginning of its development curve, British driver Rob Bell says the differences he’s found from a driving standpoint are night and day.

‘The first time I drove the 458 was the test car at Vallelunga in early March. My first impression was that the car is definitely a more stable platform to work with. At times the 430 was LE MANS 2014 47

quite edgy. And that was because they made a suspension change in 2008 based around the American scene because they didn’t use tyre warmers there. The 430 then changed suspension to work the tyres harder to get heat into them because they were losing out over the first three or four laps in the ALMS. So when they did that it made the 430 a lively car at the rear. But then what it also meant was halfway through the stint the tyres would be reacting and working harder and not necessarily being able to keep up with the suspension.

‘So you had a situation where a lot of the time when cornering the 430, the front would work into the corner but the rear would be coming round. But straight away, driving the 458, that issue seems to have disappeared altogether. It felt very, very stable on brakes and turning at the rear, which was our biggest concern when we finished with the 430. The car is a flatter car to drive, which is great in the high-speed stuff, really nice. The 458 is a case of, “wow, you can really attack the corner now and get turned in and be aggressive and not worry about the rear losing grip”. It’s a big step forward, for sure.’

Comparing the cornering attributes of the F430s and F458s at the 12 Hours of Sebring revealed how much Michelotto has accomplished by altering the ride quality of the new car. Where the F430s always used a bit of extra roll and dive to load the tyres and transfer

weight, the F458 moves visibly less while cornering and under hard braking. Simply put, the normally demonstrative moves of the Prancing Horse have been muted.

After listening in to a number of conversations in the pit lane amongst F458 drivers, perhaps too much anti-dive geometry has been used, leading to the rather numb handling sensation some drivers reported, so it is believed the first batch of updates for the F458 will include geometry revisions to mitigate this.

Bell, who took the F458’s first major international win at the Paul Ricard in April,

TYRE CHOICE The Italian AF Corse team ran Ferrari’s new bodykit at the Le Mans test day following the balance of performance testing at Ladoux, France

says his JMW team worked through a number of changes at the French circuit to try and improve the car’s straight-line limitations. ‘First, we’ve all got a new, taller Gurney on the rear now, and it’s quite obvious when you get up to a certain speed that it’s doing its job. It’s been put there to slow us down, and it does. You definitely feel like you get into top gear and not a lot really happens. So I would say that’s been true with most of the cars. Having said that, in the past with the Ferrari, when you’ve taken aero out of it, it’s responded very well.

But I think the truth will be known at Le Mans, when we start taking aero off. We took a little bit off at Paul Ricard and played with bits and bobs, and didn’t really find a huge amount, to be honest. It’s little stuff we’re looking to improve, and Michelotto will get it sorted quickly, like they always do.’

Bell also reported that the change to the Bosch MS5.1 system has been seamless so far: ‘For a completely new system it’s been a very smooth transition. And certainly everything that we’ve had so far has worked perfectly.

You’d expect electronic glitches for the first six months, but we haven’t really had any on the cars I’ve driven. And I think it’s a step forward because, for example, the traction control system is more advanced. It’s a nicer system to work with as a driver, and that can only be good – we don’t necessarily rely on traction control but, if it’s there and you don’t feel it’s working, it’s going to be looking after the tyres better than we humanly can. I think that will be seen in long durations, as it does seem to be doing its job. The Marelli system was fine, but for example its traction control felt a bit basic.’

There’s no doubt the F458 has a long way to go to catch and surpass the F430’s record in competition but, if it’s early potential is anything to go by, it looks like Munich and Detroit might have another five years of hellish fighting ahead.

TECH SPEC Length: 4518mm Width: 2036mm Height: 1160mm

F

or Le Mans 2014, Ferrari prepared a new aerodynamic kit that would allow it to compete with the Corvette C7R, the Aston Martin Vantage and the Porsche 991 RSR on a more equal footing. The Italian company had its figures verified by the FIA following the 2013 race, that it was slower by up to a second per lap around the Le Mans circuit.

A new front splitter and rear diffuser were designed to change the aero balance and give an estimated 6-8 per cent more downforce, allowing the teams running the car to run a less extreme rear wing angle. Lead driver Gianmaria Bruni explained that the car ran with a -7% rear wing in 2013, which made the car difficult to drive, particularly in the Porsche Curves.

48 LE MANS 2014

T

he aero kit was tested at Michelin’s Ladoux test facility in France at the end of May before teams were allowed to run it at the Le Mans test day, and in Le Mans. ‘We are very happy that the Ladoux test is going ahead,’ said Bruni at Spa in May. ‘Others are coming with big rear wings, and splitters, and say that they have less downforce than us. The Ladoux test will tell us all the truth.’ Following the test, at which the Corvette C7R was measured for the first time, the only change was to the Aston Martin Vantage, which received an extra five litres for its fuel allocation. Subsequent to that, following the Le Mans test, all cars were given an extra five litres (increasing Aston Martin’s allowance by 10 litres overall).

Wheelbase: 2650mm Front track: 1720mm Rear track: 1688mm Dry weight: 1245kg Tyres: front – 325/650-18 Pirelli or 300/650-18 Michelin or 300/660-18 Dunlop; rear – 325/705-18 Pirelli or 310/710-18 Michelin or 310/710-18 Dunlop Engine: naturally aspirated, 90-degree V8; 4498cc; direct injection Block: aluminium Bore: 94mm Stroke: 81mm Maximum power: 346.75Kw (465bhp) at 6250rpm Maximum torque: 520Nm at 5750rpm Transmission: Hewland six- speed sequential

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ASTON MARTIN VANTAGE V8

Ad-Vantage Aston Aston Martin introduced an impressive update to its GTE entry in 2013

The new GTE model features brand new side sills, added to counter the problem of having the exhaust running down the side of the car

T

he upgraded GTE challenger from Aston Martin launched in London in February, 2013, and the car raced for the first time in the opening round of the American Le Mans Series at Sebring in March that year and was impressive.

Under managing director and team principal at Aston Martin Racing, John Gaw, the team changed upwards of 30 per cent of the car to make it more driveable, and faster, and it was cited by the Porsche drivers as the car they most fear.

One of the main issues with the car in 2012 was the speed at which it reached its V-max on the long straights of Le Mans, Shanghai and Fuji. It was allowed to run at Le Mans without a Gurney flap, had a larger fuel tank and less weight than its rivals, all measures that the new car has been allowed to keep. For 2014, the ride height had to be raised in keeping with the other cars in the class, leading the team to be concerned about tyre wear.

Yet it still is a draggy car, despite a new rear wing that was introduced throughout the GTE field. in 2013. The Aston runs at Le Mans in 2014 with a minimum weight of 1195kg, 50kg lighter than the Corvette and 40kg lighter than Ferrari and Porsche. It has a larger air restrictor, at 29.4mm, smaller than in 2013, runs without a Gurney at Le Mans, and carries 10 litres more fuel than the Ferrari, five more than the rest of the contenders in the GTE field, with a 95-litre tank.

Fast and reliable

The Prodrive team has modified the suspension, and taken weight out of the car, making the car more driveable in the corners.

‘It is not a good aero car, which is why the air restrictor is bigger, and then we use more fuel,’ says Gaw. ‘It is a torquey engine so we are good out of the corners.’

The side sills are new, due to the problems of running the exhaust down the side of the

car and having a body made from aluminium, a metal that is very good at conducting heat. A consequence of this is that the car has a large floor area, which is an advantage. ‘[In 2012] we proved how fast and reliable the car was, and our two GTE Am entries will pick up where the Pro car finished with victory in Shanghai last year,’ added Gaw. ‘Overall, around 30 per cent of all components on the 2013-spec Pro cars are new, which makes for a significant improvement.

‘We looked at specific areas where we could take weight out of the car and redistribute it to a better location. We revised the suspension, which has not only improved the handling but, when combined with the new fly-by-wire throttle allowed under these regulations, makes the car easier to drive.

‘Our aim is to win at Le Mans and in the WEC, and we are particularly pleased to welcome such a professional driver lineup to Aston Martin Racing this year.’

LE MANS 2014 51

EQUIVALENCE OF TECHNOLOGY

E. Fuel Technology Factor (FTF) EQUIVALENCE OF TECHNOLOGY 1. Definition

revolution Fuelling

Fuelling the revolution

FTF balances gasoline and fuel engine efficiencies. FTF is computed in 2 different wa allocated energy computation (FTF average) or maximum flow computation (FTF max):

Among the new regulation changes this year, FIA-ACO Among thehuge hugeraft raftofof new regulation changes this the year, the FIA-ACO has come interesting method of regulating fuel consumption has comeup upanan interesting method of regulating fuel consumption

By RICARDO DIVILA

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( )

intentiondoes of the FIA-ACO was tocar. And in alternate plus making the whole The racestated (it ultimately the road this is a bigpropulsion systems, technologies, directly relevant to the limiting amount of fuel for the whole being factor.

FIA Torque Meter maintain spectacle, safety, considering this), but rather the by litres usedperformance, each challenge, thein gain their production in the C days efficiency fuel consumption essential. models; and two: Previousrace attempts at Group reducing fuel were Control Process V03 FIA Torque Meter lap, andrelevance also using the F1 method over thelast 20 years was a being able to showcase it in a very not satisfactory.

Going flat out at to road use, sustainable development This has two related effects: one, encouraging consumption by giving a fixed amount of fuel P Corr(t) is the corrected power [kW] Control Process V03per cent reduction. of limiting flow. teams 20 environment. the start of Group the race would bring andmaximum also to keepfuel privateer competitive. manufacturers to have apublic pertinent reason for the whole race in the C days were not

 C(t) is the instantaneous Fuel Consumption given by the fuel flow meter [g/s] chnology (FTF)  Both integrals will be computed when P Corr(t) is positive and outside braking zon THEFactor FUEL TECHNOLOGY FACTOR (FTF) nology Factor (FTF)  LT is lap time [s]

on

1 Definition

2 Measurement

line and FTF fuelbalances enginegasoline efficiencies. is computed in herand it compare is used average for and fuelFTF engine efficiencies.

FTF2isdifferent computed ways whet To check power and average consumption 2. Measurement eomputation and fuelinengine efficiencies.

FTF isit iscomputed in 2 different ways whetduring her it is used foruses: (FTFdifferent average) or maximum flow (FTF max): two ways, whether usedcomputation for allocated energy events, the FIA To check and compare average Power and average Consumption during events, FIA uses: computation or maximum flow computation (FTF max): • Fuel flow meter delivering the “C(t)” signal (instantaneous putation (FTF average)(FTF or average) maximum flow computation (FTF max):

fuel the flow)“C(t)” signal (instantaneous fuel flow)  Fuel flow meter delivering • Torque meter delivering the T(t) signal (instantaneous ICE torque)  Torque meter delivering the T(t) signal (instantaneous ICE torque) • Engine rotational speed w(t)  Engine rotational speed w(t) torque Tcorr(t). Torque meter signal is corrected by the • Corrected effect of EGERS ( ) : Torque meter signal corrected by the effect of EGERS (  Corrected torque Instantaneous corrected power is computed this way: Instantaneous corrected Power is computed this way: () () ()

With:

'Best-in-Class' brake specific fuel BSFC age i s t h•e Best-in-Class” “ Average is theAverage Brakeaverage Specific Fuel Consumption on one single lap [g/kWh]. consumption on one single lap [g/kWh]. i s t hAverage e Best-in-Class” “ Specific on one lap [g/kWh]. ass” BSFC is Average the bestBrake average BSFCFuel on Consumption one lap whatever thesingle appendix B column 'Best-in-Class' average BSFC is the best average BSFC on one lap ” Average BSFC is the best average BSFC on one lap whatever the appendix B column d. whatever the appendix B column considered. ax is the Brake Specific Consumption atconsumption maximum power [g/kwh] • BSFC the brake-specific fuel at maximum Effect of exhaust gas recovery system @Pmax isFuel 3.

Effect of Exhaust3Measurement Gas Recovery System: power [g/kwh] of average true BSFC can be altered by exhaust snergy the Brake Specific Fuel Consumption at maximum power [g/kwh] Density [MJ/kg] be which altered by counter Exhaust Gas atRecovery Systems ED is the energy density [MJ/kg] Measurement of average true gas BSFC recoverycan systems increase pressure gy Density• [MJ/kg] exhaust and therefore decrease the efficiency of the engine. pressure at exhaust and thus decrease the efficiency of the engine. This phenomenon is tak mputed this way: BSFC This phenomenon is taken into account by FIA by computing an Average is computed this way: computing torque (see paragraph b.) uted this way: • P Corr(t) is the corrected power [kW] instantaneous corrected torque. ( ) an instantaneous corrected ∫

∫

∫∫

( ) ( ) ( )

()

()

()

the corrected power [kW] • C(t) is the instantaneous fuel consumption With : With : given by the enstantaneous corrected power [kW] Fuel Consumption fuel flow meter [g/s] given by the fuel flow meter [g/s] • Tcorr(t ) = corrected instantaneous torque ( )  = Corrected instantaneous torque • Both integrals will be computed when P Corr(t) is positive and • T(t ) = torque meter signal antaneous Fuel Consumption given by the fuel flow meter [g/s] rals will be computed when P Corr(t) is positive and outside braking zones outside braking zones • T (t ) = estimated torque loss from recovery. loss ( ) =braking  outside Torque meter signal will[s]be computed when P Corr(t) is positive and zones me • LT is lap time(s) Torque loss model to be defined ( ) = estimated torque loss from recovery. Torque loss model to be defined.  s]

ement

• April 2014 72 www.racecar-engineering.com entaverage pare Power 52 LE MANS 2014and average Consumption during events, FIA uses: e average Power the and“C(t)” average Consumption during FIA uses: meter delivering signal (instantaneous F.fuelevents, Kflow) Technology

Factor (KTF)

The aim is to maintain the spectacle, the safety, relevance to road use and sustainable development

strategists to their knees when Torque sensors on the lay the teams realised that the fuel shaft – a known and validated satisfactory. flatmid-race out at thewould start of the enforce, both in the design and the –race monitored by the FIA-ACO, giving them an left in theirGoing budget technology will measure race would bring strategists to their knees when strategies to use, but it does allow enginedelivered to equally interesting challenge. not bring the car to the end at the horsepower the teams thatthe thespectacle. fuel left in their designers to concentrate energy efficiency I have spoken before about the unintended that pace,realised hobbling theongearbox.

Secondly is the budget mid-race would not bring the car to the rather than the continual and expensive consequences of regulations for road cars, One can not carp as that gave measurement of the engine RPM, endmy at that evolutionary war between theobtained regulationfrom the ECU, including the bizarre old French equation that me firstpace, win –hobbling albeit inthe C2spectacle. easily I can’t that gave me my firstincentives win engineers. both together then giving the specified final drive ratioafor taxation purposes. to introduce or use class – at complain, Le Mans inas1985, when speed at 1000rpmmakers at eachand ratio – albeit in C2 class – atprogram Le Mans in 1985, when now bein designed for the fuel flow The French CV (in its fiscal power incarnation) large diversity of technologies, the paleo computer expressed in kph that As thethe carengines could can power kW; thirdly, paleo computer program the So configuration preferred byineach originally specified inan1956 astheoretically a tax to top achieve. but at thewas same time maintain Ithe was using doled out a strictI was using doled if you meter g/s. All of these factors out a strict consumption/lap timethat strategy that manufacturer up in thethe retirees and was by equilibrium casefund, of faster or calculated consumption/lap time strategy ever wondered why the ratios ofin line with aretheir the production parameters entered to left us behind during the opening hours, but priorities, this will bring in a widethe variety using the bore, stroke, number of cylinders, RPM slower development cycles. left us behind during the opening French cars of that period were a calculate Brake Specific Fuel when reality struck, the competing teams let us of methods that will depend on additional and a coefficient V (respectively for diesel and The challenge for the teams hours, but when reality struck, the bit strange, it did have a reason.

Consumption (BSFC). romp away to a five-lap by away the end. is to develop instrumentation that is now enforced on the petrol).

It could defined competing teams let uslead romp their carsbe inside theby the cubic Bycapacity 1998, sanity (of sorts) The fuel flow meter is a new cars to normalise bybe themonitored fuel type, acknowledging to a five-lap lead by the end. rules. Andmultiplied this must prevailed and the calculation was the performance. system in endurance racing and Torque the sensors on the lay shaft – a demands known on the differentgiving energetic capacities.

Interestingly, the V Use whatever air intake method by the FIA-ACO, them an simply expressed by taking poses several measure the the coefficient atchallenge. the time was 5.7294maximum for petrol and equally interesting and engine layout you want. You power ofand thevalidated engine technology in race– will teams, one being Use whatever air intake and engine I have4.0106 to the gearbox.

Seconda receptacle forbefore diesel, about giving a ratio of 1.4285643. spoken only get so much fuel method per lap, and kW divided by 40, horsepower then havingdelivered this necessity of having layout youexceed want. You only get much fuelthe unintended the measurement of in thethe engine RPM,to lodge the two Theconsequences input of gear ratios drive of and final it cannot a given ratesofor value raised to theispower of 1.6 chassis per lap, and it cannot exceed a given rate for came in 1977, when using the cubic capacity, easily obtained from the ECU, both together regulations for road cars, including both petrol and diesel respectively and adding the emission of CO2 sensors in the case of no return both–petrol diesel respectively the bizarre old French equation and more and interestingly – by theand – more in g/km divided by 45, giving the to the tank, and three if there is interestingly by theused. hybrid power level used. that specified final drive ratio for hybrid power– level fiscal power, rounded off to the a return line there.

Such a long Suchintricacies intricaciesmay maybebe a way taxation purposes. The French CV nearest integer.

They are configured much from way the reasons thereasons fans follow long from the theracing – (in its fiscal power incarnation) was This approach seems to have as the F1 fuel flow sensors and Measurement of average true BSFC can be altered by Exhaust Gas Recovery Systemsinwhich increase counter beingfollow there to see drivers competing fans racing – being there – but originally specified in 1956 as a inspired the equations that will fact use the same suppliers the good thing about the way it is being to see drivers competingand – butthus the decrease tax to topthe up the retirees fund, control the cars this year, and will (which measures ultrasonically at pressure at exhaust efficiency of and the engine.

This phenomenon is taken into account

by FIA by with the petrol at 1be and diesel presented the public is by itthe then to giving the power in kW; nominally thirdly, thewith fuel an accuracy was calculated bycoefficient using thefor bore, good thingtoabout the way is clear a bit of a headache enforce, 2kHz computing an instantaneous corrected torque (see paragraph b.)

0.7, andofthe factor K derived the averaged presentation of thetogoals, in the is statement stroke, that number in g/s. All ofof these are per the cent error, cylinders, RPM fromboth being presented the public in the designflow and meter the race maxfactors +/- 0.25 mean speed at 1000rpm at each ratio expressed thethe carsclear will be 30 per cent more parameters calculate the Brake and a coefficient V (respectively by presentation of thefuel efficient strategies to use, but it does entered allow to theoretically well within the kphpetrol). that theIt car achieve. with the performance, and Specific Fuel Consumption (BSFC).2 per cent margin of error and could goals, insame the statement that thethat this for dieselin designers concentrate specified ( could ) be theoretically ( ) engine ( ) to Sothe if you evercapacity wondered why theon ratios of efficiency rather goalpost will30 be per moved year.

The fuelthan flow meterdemanded is a new system in regulations). defined by cubic cars will be centeach more energy by the oftype, that period were a the bit strange, it and expensive other championships endurance racing and poses several demands by thecars fuel fuelUnlike efficient with the same where the multipliedFrench continual The EOT is defined as an did have a reason.energetic Balance on the race teams, one equivalence being the necessity of controlled With : of Performance different performance, and that (BoP) this is used to acknowledging evolutionary war between the of BSFC, By 1998, sanity (ofVsorts) prevailed and themakers having equalise disparate production to provide a receptacle in the chassisfactors. to lodgeThese the are: the capacities. Interestingly, the goalpost will be moved eachcars year. regulation and engineers. by three ) = Corrected  field in the( interest instantaneous torque calculation waswas simply expressed by As taking a level of competition, the whenTechnology there is no return coefficient at the time 5.7294 Differently from other thethe engines sensors: can nowyou beneed two Fuel Factor (FTF), ( )have  rules =where Torque meter signal power of the engine indesigned kW divided FIA-ACO introduced the concept of petrolmaximum line to the tank, three when there is. Factor (KTF) and for and 4.0106 for diesel, championships the Balance forbythe configuration K Technology then having this value raised to the power Equivalence of Technology (EoT) to that provides They are configured much the F1 giving a ratio of 1.4285643. of is used preferred by each manufacturer in the ERSasIncentive. ( (BoP) ) = estimated torque loss40,from recovery. Torque loss model to be defined. Performance fuel flowpriorities, sensors and in factSouse the same BSFC is the of 1.6ofand adding emission ofline CO2with in g/km incentivesdisparate to introduce or use a large diversity The input gear ratiosthe and equalise production their production the average suppliers.

They measureratio ultrasonically at by1977, 45, giving the fiscal power, rounded of technologies, at the same final drivedivided came in when cars to provide but a level field in time maintain this will bring in a wide variety of two integrals.

These will 2kHz nominally accuracy of max to the nearestwith integer. an equilibrium the case of faster using theoff cubic capacity, the interest ofincompetition, the or slower of methods that will depend on with anbe computed when P Corr (t) is +/- 0.25 per cent error, theoretically Thisfor approach inspired instrumentation development the coefficient petrol atseems 1 to have additional FIA-ACO rulescycles. have introduced that positive andwell outside braking zones, equations willKcontrol theiscars theto specified 2 per margin of error zones challenge for the teamsofis to develop theThe concept of Equivalence and dieselthe 0.7, and thethat factor now enforced onwithin the cars notcent otherwise.

Braking this year, and will bemean a bit of a headache to the performance. demanded by the regulations. their cars inside the that rules.provides And this must bederived from the averaged Technology (EoT) normalise are defined as the longitudinal

Clear goals

The aim is to maintain the spectacle, the safety, relevance to road use and sustainable development

3. Effect of Exhaust Gas Recovery System:

F. K Technology Factor (KTF) 1. Definition

KTFTHE balances fuel and gasoline engine K TECHNOLOGY FACTOR (KTF) weights. The heaviest technology is handicapped because it does not allow embedding the same amount of ERS as the lightest technology.

KTF balances fuel and gasoline engine weights. The heaviest technology is handicapped because it does not allow embedding the same amount of ERS as the lightest technology

• • With • • • • • •

 

(

)

if

(

)

if

EGasoline is the allocated gasoline energy in Appendix B [MJ] FTF the fuel technology factor defined in paragraph 1 EAdditional is the additional allocated Diesel Energy due to technology differences. It can be negative [MJ] isweight the allocated Gasoline Energy in Appendix B [MJ]the appendix B column considered [kg] WBest Diesel is the of the Diesel ICE with the best average BSFC whatever WBest the Technology weight of the Gasoline with theinbest average BSFC whatever the appendix B column considered [kg] FTFGasoline the isfuel FactorICE defined paragraph 1 [-] ρERS-Diesel is the best-in-class ERS density among diesel cars only [s/kg] the additional allocated Diesel Energy ρERS-Gasoline is theis best-in-class ERS density among gasoline cars only due [s/kg]to technology differences. It can be negative [MJ] XFuel on lap time is the effect of additional Fuel on lap time [s/MJ]

is the weight of the Diesel ICE with the best average BSFC whatever the appendix B column 73 April 2014 • www.racecar-engineering.com 73 considered [kg] LE MANS 2014 53 is the weight of the Gasoline ICE with the best average BSFC whatever the appendix B column

. ERS incentive

EQUIVALENCE OFOF TECHNOLOGY 1. Definition EQUIVALENCE TECHNOLOGY

dix B has been computed based on the Committee recommendations, in order to conserve an incentive for S system. Simulated theoretical incentive in Appendix B is: An additional 20kg (and reduction in car mass is The values of BSFC THE ERS INCENTIVE ~-0.5s/lap/MJ hybrid given to necessary a no-ERS car, ERSERS) car weight is weights for while KTF and

now 870kg, 45kg but less disclosed than the previous rules. were confidential to the manufacturers, Theother energy values of theand ERSais detailed in dix B is between columnsis to be applied dissuasive two tables,penalty one for Le Mans, and a correction at Le Mans in case of thethe amount be wrong in case of discrepancies between 2012 and 2014 data (e.g. significant increase of chassis weight factor for the otherone circuits, manufacturers has declared data by the is currently based on Manufacturers data given in 2012, theoretical hierarchy between will decide of releasable energy ut ICE). InAppendix 2014, Bafter having weighed every car, system andbutcomponent, Commission or not to being limited too far from reality. columns could be wrong in case of discrepancies between 2012 and 2014 data (eg significant increase of proportion of the length of the circuit e the Appendix B in order to conserve the hierarchy.

The temptation to run a higher chassis weight without ICE). In 2014, after having weighed every car, system and component, Commission relative to the length of the Le Mans circuit power for a qualifying lap is now will decide or not to change the Appendix B in order to conserve the hierarchy. multiplied by a factor of 1.55, and the amount deterred by the penalties defined ommittee decision will be based on comparison of the optimum Hybrid LMP1 car weight and in the of fuelminimum likewise, butand multiplied the regulations, likewiseby a factor The Committee decision will be based on comparison of the optimum Hybrid LMP1 car weight and the of 1.11,race, as detailed in the Annexe in the as cross-checking of B of the tory LMP1-H weight (870kg). minimum regulatory LMP1-H weight (870kg).

LMP1 Technical Regulations. the FIA's data against that of The optimum Hybrid car will weight be estimated FIAthis this way: ptimum Hybrid LMP1 car LMP1 weight bewill estimated bybyFIA way: will be an will increase in lap time, the There manufacturers be carried out events and during the carsthe willfirst stilltwo be fast, but now the and official sessions engines willtesting not be run on a maximum Where: before Le Mans 2014.of developing engines power mode.

Instead • WOptimum is the optimum Hybrid LMP1 car weight e: theinresults are considered to they • WBest Chassis is the weight of the lightest chassis whatever the column or the technology (Diesel or thatIfrun a maximum power state, be correct, they will be maintained is the considered[kg] optimum Hybrid LMP1 car weight Gasoline) will be run in a state that has much more until Le Mans. In the event of • WBest ICE is the weight of the lightest ICE whatever the column or the technology (Diesel or Gasoline) relevance for our daily driving. Reducing is the weight of the lightest chassis whatever the column or the technology (Diesel or Gasoline) abnormal results from data considered [kg] drag will still be important, but the narrower measurement or expertise of FIA, considered[kg] • W8 Best MJ ERS is the weight of 8MJ system computed with the best ERS density [MJ/kg] whatever body width will reduce frontal area, despite emergency meeting can be held the or the technology (Diesel or Gasoline) consideredthe [kg] column or the technology (Dieselanor is column the weight of the lightest ICE whatever Gasoline) having to raise the driver for the new with the manufacturers concerned. visibility template. emphasis will shift The good pointThe in this considered [kg] from aerowill development fuelwill efficiency, approach be that thetoEoT is the weight of 8MJ system computed with the best ERS density [MJ/kg] whatever the column be transparent process.

This is that hasofmuch more relevance for or 142.1MJ/lap of diesel acceleration being lower The EOT than is defined as anenergy equivalence of butadownforce will be affected.

We should altering the measure the true average BSFC, or the-1.0g technology (Diesel orby Gasoline) considered described by the daily driving.

Reducing drag at a max petrol flow[kg] of 95.6kg/h, and lastBSFC, until the acceleration controlled three factors.

These are: expect to see L/Dsrules: touching 5, compared and then the our FIA corrects the computation of for diesels, and for will still be important, butformula the becomes positive andTechnology greater thanFactor83.4kg/h the Fuel (FTF), K Technology to the 4.2 to 4.3 today in LM trim. thethe instantaneous torque by using the 'Models used [are] described body width manufacturers, who must run +0.1g (these Factor factors(KTF) being bythe ERS Incentive. and shown in the narrower FTF calculations box. will reduce with disclosed formulas. frontal area, despite having two all the way to vehicle speed calibrated on GPS So, the average BSFC is hybrids the ratiofrom of two Furthermore, KTF balances fuel and gasoline Accelerations sectors information to raise the driver for the new 8MJ/lap with accordingly reduced system). Pcorr uses the approved integrals. These will be computed when Pcorr engine weights. The heaviest technology is [willway: be] made officially available visibilityFIA/ACO template. The emphasis petrol (134.9MJ/lap) orconserve diesel torque meter, and decide is considered e Commission would to change Appendix B to incentive, will proceed this There will be an increased interest in (t) is positive and outside braking zones, not handicapped because it does not allow the for competitors. will shift from aero development energy (127.1MJ/lap) and flow. negative as soon as it becomes howA this willengine, be usedERS in the otherwise.

Braking zones are the same offuel ERSeffi as the lightest Theoretical Gap between columns would beascomputed thanks totosimulation. list of andrace strategy ciency, but technology. downforce Andefined additional 20kg reduction in amount lower than 0kW. It lasts until and qualifying tactics, and raises longitudinal acceleration being lower than -1.0g The balance equation is also inWe theshould FTF box. chassis parameters are asked to several will be affected. expect car mass is given to a no ERS Pcorr becomes positive and greater This gap defined by the commission would be defined for Le Mans only. interesting scenarios.

This positive The use oftoenergy recuperation systems manufacturers in order to:is also controlled car,becomes down from the 870kg for ERS, see L/Ds touching 5, compared than +10kW. and last until the acceleration ColumnsThe could be greater adjusted with: Allowed Fossil Energy and/or Maximum Fuel Flow and/or •by Fuel Capacity will be essential in extending range of trim. the rules, andand specifically by the fuel and than factors being Compute FTF KTF to the 4.2 to 4.3the today in LM frequency of all of the+0.1g (these 30kg less than the previous rules.

•flow Rescale torque Sandbagging meter acquisition channels used for thisspeed on the GPS system). the fuel allotted, and the amount harvested monitoring. in the initial calibrated by vehicle carried on board.

•data Post-process race data' the two races computation Pcorr is 100Hz. can be used in various options. These range supplied or in running uses the approved torque meter, and Page 5 /7 The Exhaust Gas Recovery from none – the probable case for privateers before Le Mans was pre-empted for the is considered negative as soon as it becomes are, however, aoflot of LMP1 Systems can lower increase as it would reduce development costs but allow firstThere year of application new thancounter 0kW. It lasts until Pcorr becomes clever people out there juggling the plus pressure at the exhaust, 150.8MJ/lap of petrol energy or 142.1MJ/lap of regulations (ie two first races of 2014 positive and greater than +10kW. what-ifs, and to close the loopholes decreasing the efficiency of diesel at a max petrol flow of 95.6kg/h, 83.4kg/h Le Mans 2014), for the EoT was defined as based The frequency of all of the acquisition there will be 'dissuasive penalties': the engine, so altering the for diesels – to the manufacturers, who must run on data delivered to FIA by manufacturers channels used for this computation is 100Hz. measure of the true average BSFC, hybrids from 2MJThere all thewill way to 8MJ/lap with last'IfDecember, reviewed in January, and The Exhaust Gas Recovery The Systems can the FIA notices during the energy values of the ERS be an increased and then the FIA corrects the accordingly reduced petrol (134.9MJ/lap) or then the final set data was sent by increase counter pressure at the exhaust, race that a car hasofan average interest in how this will be is detailed in two tables, one for Le computation of the instantaneous diesel energy (127.1MJ/lap) and flow. manufacturers to FIA in February. decreasing the efficiency of the engine, so or instantaneous (P max) BSFC used in the race strategy and torque by using the formula Mans, and a correction factor for The values ofwas BSFCannounced (and weights exceeding what the other circuits, the amount of qualifying tactics, and raises shown on p72. necessary andthan ERS)2were in Februaryfor byKTF more per confidential several interesting scenarios. This Furthermore, KTF balances releasable energy being limited THE ACO PERSPECTIVE cent (estimation of the maximum is also controlled by the rules, fuel and gasoline engine weights. by the proportion of the length of but disclosed to the other manufacturers, error the sensors), andistotothe The heaviest technology the circuit relative to thethat length of and specifi cally by the ‘If we see at Le Mans been the BSFC. If we havefuel to flow e don’t care if youishave and aofdissuasive penalty be applied at advantage of this car, the Le Mans circuit multiplied by monitoring.

Sandbagging in the handicapped because it does not adjust we will do so. turbo, or normally their BSFC is not the one that Le Mans in case one ofthe thetechnical manufacturers has delegate shall too inform the stewards, athey factor ofdeclared, 1.55, andthey the will amount initial suppliedtoor in arunning allow the same of’ says ERS ‘Youdata are allowed use certain aspirated, KERS,amount whatever, have declared data far from reality. after which there will be an open as the lightest technology. The of fuel likewise, but multiplied the two races before Le Mans amount of fuel per lap. If you the ACO’s sporting director, have a sanction. If they lie they will The temptation to run a higher power debate with the competitor in by a factor of 1.11, as detailed was pre-empted for the first balance equation is also on p72. exceed this amount, there are two Vincent Beaumesnil. ‘We just have no chance to win the race for a qualifying lap is now deterred by the order to propose to him a minimum year of application of new LMP1 in the Annexe B of the LMP1 The use of energy recuperation possibilities. If the excess is within want to make sure that fuel and because we will stop them. penalties defined in the regulations, and stop and go penalty of 60 regulations (ie two first races of systems will be essential in Technical Regulations.

2 per cent, then you have the two diesel have the same chance to ‘We have a first set of figures likewise in the race, as cross-checking of the seconds (which can be extended There will be an increase in lap 2014 plus Le Mans 2014), for the extending the range of the fuel following make an average. win. Forand that,the theamount figure we are received thecars endwill of January, FIA’s againstofthat the manufacturers will at thedata discretion theofstewards EoT waslaps defito ned as based on data time, andatthe still be fast, allotted, harvested As long as you make average on considering the Brake Specific andnow a second set of figures be carriedto out during the of first two events and according the duration the delivered to FIA byan manufacturers can be used inisvarious options. but the engines will not be three laps that is OK, you willinhave Fuel Consumption, the ratio adjusted just beforepower the firstmode. race, official testingnoted, sessions before infringement ie the timeLe Mans 2014.

These range from none, the run on a maximum last December, reviewed during which theare competitor ranto be correct, January, and the finalthis setlive. of Instead developing probable privateers and as it no stop and go.then We monitor betweencase fuelfor consumption and thatofwill be the finalengines figure.

If the results considered while exceeding the authorised data was issent by manufacturers would reduce development costs that run in a of maximum power ‘There no way for a performance.

The manufacturers Equivalence Technology is they will be maintained until Le Mans. In values).

The duration will be from data but allow 150.8their MJ/lap of petrol state, they will run infuel a state to FIA in February. manufacturer to hide anything. No have declared figures, and only this year tobe balance the event of abnormal results Appendix B has been computed based on the Endurance Committee recommendations, in order to conserve an incentive for big ERS Simulated theoretical incentive Appendix B is: currently based onsystem.

Manufacturers data given inin2012, but theoretical hierarchy ~-0.5s/lap/MJ hybrid

2. Process

Checks and balances

The use of energy recuperation systems will be essential to extend the range of the fuel allotted

‘W

from there we define how much fuel they will have.

and diesel. After Le Mans, every year, we will look at what has

74 www.racecar-engineering.com • April 2014

54 LE MANS 2014

EOT-SGAC.indd 74

sandbagging, we will just have the truth and balance it correctly.’

measurement or expertise of FIA, an emergency meeting can be held with the manufacturers concerned.

24/02/2014 09:39

EQUIVALENCE OF TECHNOLOGY ARCHITECTURE OF WEC 2014 Analog sensors: FIA Flow Meter 1

▼

▼ Data Logger FIA/ACO

▼

HV Intensity and Voltage (if FIA recommended sensor)

Analog sensors for EGERS System:

▼

▼

▼

CAN 1/Public

▼

ECU/Datalogger TEAM

• Bost pressure • Airbox pressure • Oil Tank level • Cockpit Temp • MGUs current • MGUs voltage • Torquemeter • Beacon • Fuel pressure censor

FIA Flow Meter 2

Manufacturers Spec with FIA approved (compatability with FIA logger)

Torquemeter (Also connected on analog input)

• Exhaust pressure censor • EGERS intensity • EGERS voltage (if not on the same DC bus as MGU)

FIA/ACO Leader light module

Analog sensors FFM backup: Manufacturer spec with FIA-approved (compatability with FIA logger)

• Engine revs • Intake manifold temp • Fuel temp

▼ CAN 2/FIA ACO Private

▼

▼

FIA Telemetry

GPS Module

▼ GPS antenna

▼ FIA/ACO Transponder

Marshalling Display

▼ FIA ADR

▼ FIA/ACO Compact Card Reader

▼ CAN Lambda Module (if backup FFM)

▼

▼ Telem antenna

▼

Lambda sensor

recorded on the basis of the onwill be no exclusion penalty; include an analysis of the other “streamline” our methods, but The good thing about this approach is that it If this hints at ‘we’ll make it up as we during which the competitor ran while exceeding board sensors (fuel flow meter and however, a fine could be imposed data at the disposal of the FIA without applying penalties will ensure that EoT will be a transparent process. go along’, as an engineer I at least applaud the authorised values). The duration will be torque meter), information which after the race on a manufacturer (reverse engineering).' (except in the case of a significant This is described by the rules: the facing up to the reality of continuously recorded on the basis of the on-board sensors will be available to the competitor. who has intentionally provided breach of the values established The models used are described with changing technical knowledge and that it (fuel flow meter and torque meter), information 'If the competitor accepts the incorrect values in order to bias One interesting inclusion is beforehand). Our results will be disclosed formulas.

Acceleration sectors will attain the main objective of pushing which will be available to the competitor. penalty, official notification will the EoT process.' the following: communicated to the competitors information [will be] made officially available development in fuel efficiency without losing ‘If the competitor accepts the penalty, official be issued to the competitor and Furthermore, 'the detailed for joint recalibration.' for competitors. the spectacle.

The con, however, is that notification will be issued to the competitor penalty will be applied. If the post-race analysis could involve 'For the first two races of A list of engine, ERS and chassis parameters penalty will be applied. If the the competitor competitor then returns, until the tests andand inspections with season and the preliminary If this hints at 'We'll make it up are asked to manufacturers in order to: then returns, until the end of the race, the end of the race, to the BSFC/KTF the competitor or elsewhere teststoat Le Mans, we propose as we go along', as an engineer I BSFC/KTF he had there will bethe BSFC and to that he had announced, there (calibration sensorthat check), andannounced, will to monitor applaud the facing up to the reality • Compute FTF and KTF no exclusion penalty; however, a fine could be of continuously changing technical • Rescale torque meter imposed after the race on a manufacturer who knowledge and that it will attain ACO PERSPECTIVE • THE Post-process race data’ has intentionally provided incorrect values in the main objective of pushing order the EoT process.’ what has been the BSFC. If we development in fuel efficiency e don’t care if you ‘If we seeto atbias Le Mans There are, however, clever or people out therethat their BSFC Furthermore, ‘the detailed without losing the spectacle. The have turbo, is not the one post-race haveanalysis to adjust we will do so. juggling the what-ifs, and to close the loopholes could involve tests and inspections with'You theare allowed to use a con, however, is that spectators normally aspirated, that they have declared, they there will be ‘dissuasivesays penalties’: might beingend a bitupconfused competitor or elsewhere sensoramount check), of spectators being a bit confused KERS, whatever,’ the ‘If the FIA will have a sanction.

If they (calibration certain fuel per lap.

If end upmight notices during the race that a car has an average if not kept informed the breach of include an analysis of the other data at the if not kept informed as to the ACO’s sporting director, Vincent lieortheyand willwill have no chance you exceed this amount, there are as to instantaneous (P max) exceeding could also Good disposal the FIA (reverse ’ breach of limitations.

Beaumesnil.

‘We BSFC just want to what was to win the raceofbecause we engineering). two possibilities.

Iflimitations. the excessGood is communication announced in February by and morediesel than 2 per cent spice you up the perceived competition.

One interesting inclusion is the following: communication could also spice up make sure that fuel will stop them. within 2 per cent, then have (estimation of the maximum error of the sensors), The backup precision ‘For the first two races of the season and the the perceived competition. have the same chance to win.

‘We have a first set of the two following laps to make anplan of changing to 3 per cent on fuel metering for instantaneous andFor to the advantage of this car, the technical preliminary tests at Le Mans, we propose to The backup plan of changing that, the figure we are figures received at the end of average. As long as you make an BSFCthat computation a logical plan delegate shall inform theBrake stewards, aftercwhichJanuary,monitor the BSFCset andofto “streamline” our on three laps to 3 B, per cent on fuel considering is the Specifi and a second average is OK, givesprecision andand acknowledges the sensorfor might there willConsumption, be an open debate instantaneous BSFC Fuel thewith ratiothe competitor figures methods, adjusted but justwithout beforeapplying penalties you will have no stop go. We that metering in order to propose to him a minimum in the casewill of abe significantmonitor breach this live. not be up to speed yet. computation gives a logical plan B, between fuel consumption andstop andthe first(except race, and that values establishedofbeforehand).

Our is no way for Asaan executive brief,and we acknowledges can certainly saythat the sensor go performance. penalty of 60 seconds (which can be extended The manufacturers the finaloffithe gure.

Equivalence ‘There results bethis communicated competitorsto hide thatanything. exciting times are ahead the yet. at the discretion of the stewards according mightand notheading be up toinspeed have declared their figures, and to the Technology iswill only year to to the manufacturer for joint recalibration. ’ right direction. duration of the infringement noted, ie the time As an executive brief we can from there we define how much balance fuel and diesel. After Le No sandbagging, we will just have say exciting times are ahead and fuel they will have.

Mans, every year, we will look at the truth and balance it correctly.’

MANS 2014 55 heading in the rightLEdirection.

‘W

There are people out there juggling the ‘what-ifs’, so to close the loopholes there will be ‘dissuasive penalties’

NISSAN ZEOD

Ben Bowlby and the

Nissan

ZEOD With his latest project, the British-born engineer has landed his second Garage 56 slot in three years. And here’s why…

By PETER WRIGHT

56 LE MANS 2014

Bowlby is a racing car engineer who relishes conceiving and designing cars unconstrained by regulations

I

f there is a visionary engineer in motorsport today, it is surely Ben Bowlby who qualifies for the title. Having conceived the DeltaWing as a sustainable, 300hp solution for IRL, been rejected in favour of sticking with the 600hp dinosaurs of the ovals, he successfully wooed the ACO to consider the car in two-seater form for their forward-thinking Garage 56 slot in the 2012 Le Mans. The boldness of the concept not only attracted key partners Nissan and Michelin, but also caught the imagination of young people – potential fans that are missing from so much of motorsport. Why? The car was ‘cool’ and ticked many of the sustainability boxes that matter to this generation.

The DeltaWing went on to deliver most of what it promised and proved that current racing car design is twice as heavy, twice as powerful and twice as consuming of fuel and emitting of CO2 as it needs to be. Nissan, like the rest of the automotive industry, is right in the middle of trying to establish what configuration of cars consumers are going to buy in the future. You can talk about technology, create show cars and prototypes, customer-test limited numbers of new concepts, but until you offer consumers production versions with actual performance, actual range and actual costs, you don’t find out if you are right or wrong.

Nissan is at the forefront of EVs, with its pioneering Leaf.

However, as with other similar EVs, it is not achieving sales targets as consumers are put off by cost and range limitation.

The whole EV experiment is beginning to confirm that these vehicles have a real application in cities and in commuting from the suburbs, but really only for people who either use a car for nothing else, or are well-off enough to afford other vehicles for long distance and family motoring. The potential best compromise is the plug-in hybrid: battery power for city use, and efficient IC engine for intercity and rural journeys.

Motorsport is a great demonstrator of the status of new and emerging technologies, and it is for this that Nissan has taken Bowlby’s efficient racing vehicle technologies and is wedding

them to their hybrid technology in the Nissan ZEOD for Garage 56 at the 2014 Le Mans race.

EV racing cars have already demonstrated performance at the Nürburgring Nordschleife (Toyota), and Pikes Peak (Nobuhiro ‘Monster’ Tajima), as well as showing their outright speed potential (Drayson Lola), but they run out of puff after around 15-20km at racing speeds, and none of the venues have anything like the cachet of Le Mans. Achieving a lap of Le Mans at racing speed on battery/electric power alone is obviously feasible, but would be all over in under four minutes, leaving 23 hours and 56 minutes during which the achievement might be forgotten. Racing for the full 24-hours, with one lap in each 12 lap stint in ZE mode under electric power alone, and the other 11 laps in serieshybrid mode, using a tiny efficient IC engine, is feasible.

This cycle would emulate a potential cycle for such a hybrid road car and would be noticed – and that is what the ZEOD hopes to achieve.

Bowlby is a racing car engineer who relishes conceiving and designing cars unconstrained by regulations, a situation that is rare outside land speed record attempts, and leads to frustration in many in F1 design today. In the ACO’s Garage 56, he has found the freedom to exploit his vision – although the ACO does impose certain some constraints – and it is a partnership unique in motorsport. The car must of course meet the highest LMP1 and FIA standards of safety and – crucially – must not be faster than the Audis, Porsches, or Toyotas. One further condition the ACO has imposed on Nissan is that, to justify their second occupancy of Garage 56 in three years, the ZEOD must be a step to a full Nissan LMP1 challenge at Le Mans and in the WEC. The performance the ZEOD is targeting is: • •

In ZE, pure EV mode – faster than the GTs In hybrid IC engine mode – LMP2 performance

LE MANS 2014 57

NISSAN ZEOD

The ZEOD weighs 700kg with driver and 50 litres of fuel, considerably heavier than the DeltaWing

It is planned that the first 11 laps of the stint will be in the latter mode and then, with the fuel tank empty and battery fully charged, it will do one lap as an EV. The fact that this last lap of a stint will end up in the pits means that it will not be timed as a flying lap, but no doubt Nissan will arrange for a flying ZE lap for the record.

Bowlby is contracted as a consultant to Nismo – Nissan’s motorsports division. Nismo have contracted Ray Mallock’s RML Group to design and build the car, while Nissan

As with the DeltaWing, Bowlby tested the ZEOD’s stability by dropping a scale model down the side of a swimming pool with concave walls provides the full hybrid powertrain, IC engine, electric motors, batteries and all the associated controllers, and Michelin returning as the chosen tyre partner. RML then sub-contracted Bowlby to carry out the aerodynamic design over an intense three month period, and he supplied full body design and cooling data to RML. The aerodynamics are all-new, and the 58 LE MANS 2014

closed car is significantly different from the open DeltaWing. All downforce is generated by the underbody and Bowlby has taken great care once again with the aerodynamic stability of the car. Further developing his unique technique – as applied to the DeltaWing – of testing the stability of an 1/18th scale model (for equivalent Reynolds number in water) by dropping it down the side of a swimming pool both forwards, sideways, and backwards. He found a pool with concave walls and the model stuck to the wall under all conditions. These results, combined with FIA LMP1 standard crash tests adapted for the lower weight of the car, met the second item of Nissan’s brief to the RML designers: Design and build it: • • •

Fast enough Safe enough Reliable enough to finish the Le Mans 24hour race

Without the constraint of regulation, there might be a temptation to include all sorts of trick stuff on the car. However, it is novel enough in so many areas that the rest is really pretty conventional, giving it the best chance of achieving the third item on his list in the limited development time available.

The first item – faster – is a bit more complex and considerably more difficult. To accomplish its demonstration of ZEOD [Zero Emissions on Demand], it starts with a disadvantage. In ZE

mode, it has to carry around, unused, the IC engine and all its ancillaries and cooling system, and including the fuel tank, albeit empty for the demonstration lap. In hybrid mode it has the burden of the excess batteries over and above the energy storage needs of KERS operation.

Let’s look at the ZE mode first, as this sizes the batteries and motors. The ZEOD is fitted with two 110kW continuously-rated motors giving 291hp in total, mounted alongside the fivespeed transmission and driving the input shaft of the gearbox. The transmission is there by necessity for the IC engine. What is gained is that the motors can work within a narrow, optimised RPM range and as a result the batteries can be smaller and lighter. What is lost is the ability to drive each rear wheel individually, providing differential action and – subject to agreement with the ACO – torque vectoring. The batteries are the same chemistry as the Nissan Leaf’s cells, and provide 12kWh (43MJ) of usable energy storage, weighing in at 120kg.

There is no way the ZEOD – which tips the scales at 700kg with driver and 50 litres of fuel, with just under 300hp, equivalent to 2.33kg/hp – could ever be as light as the DeltaWing’s 570kg in the same condition. With just about the same electric power as the four-cylinder Nissan engine in the latter car (1.9kg/hp), the ZEOD must be slower under electric power alone.

On top of that, the extra weight requires more downforce, and hence inevitably more drag. Put

engine to operate between 6000–7200rpm. As mentioned earlier, the motor/generators and battery also benefit from this arrangement.

This motorcycle-sized IC engine is AVmounted behind the rearmost part of the monocoque, which forms the 50-litre fuel tank and also houses the batteries, accessible from beneath the car. AV mounting gives all the electronic accessories and other delicate parts the best possible reliability environment.

Cooling of the various systems is split into two, with a radiator behind each rear wheel fed by a small pitot intake above the wheel, and exhausting into the base region behind the car for excellent aerodynamic efficiency.

One circuit cools the IC engine and motor/ generators using glycol; the other cools the turbocharger’s intercooler and the batteries with a dielectric fluid. When the IC engine is working hard, the motor/generators are not on a continuous duty cycle, so can share their cooling system. When the batteries are working hard in the ZE mode, the turbocharged intake air is not needed and so these two can also share a cooling system. Neat!

Proving the technology

Top: The powertrain will not be load bearing so a tubular steel structure has to be fitted to the rear of the tub Above: Here we get a good look at the front suspension of the car, note the design of the upper wishbone.

in more electric power to compensate and the battery weight goes up: a vicious upward spiral.

Reversing the direction of the spiral, which is the Ben Bowlby doctrine, and reducing size, weight, downforce, drag, power, and energy storage is limited by the need to accommodate a driver plus the space for a passenger, and to provide safety protection for the former.

It is worth noting here that SuperKarts, with their 60-90hp and 200kg are just as fast around a circuit as a Radical SR3, with 220hp and 650kg, so this philosophy does work right on down to very low mass if you can race such a vehicle to the appropriate regulations.

The ZE range is one lap of Le Mans, the other 11 laps of a stint being in hybrid mode.

Power for this will come from a specially designed Nissan, three-cylinder, 1.5-litre, turbo GDI engine, producing 260kW (350hp). It will not be a true series-hybrid, with the engine running at constant speed to generate electrical energy stored in the batteries because that transmission path is just too inefficient. Like the Chevrolet Volt, the engine will transmit power directly and mechanically to the rear axle as well as driving the generators. While the Volt only does this in top gear, the ZEOD will use a five-speed conventional gearbox allowing the

There is no requirement to run a fuel flowmetering device, as Garage 56 does not have a fuel flow limit. Nissan may run one of the LMP devices to gain experience of it for future application in their LMP1 car. Nissan’s objectives for the ZEOD are no walk in the park.

To be able to race competitively at Le Mans for 11 laps then complete a 12th lap – albeit at slightly reduced speed – in ZE mode is quite a challenge. Nissan want to demonstrate the status of their technology for a road car cycle of, by way of example, driving from Birmingham to the M25 around London at high speeds on the motorway, switching to ZE, all-electric mode within the M25, then filling up the fuel tank and driving back to Birmingham. This is very likely to become one of the definitive road car cycles for which manufacturers develop mainstream cars. Simulation shows that Ben’s ZEOD car with Nissan’s powertrain technology can achieve this.

Bowlby’s proven philosophy of reducing the scale of everything to achieve efficiency – although not yet widely adopted in motorsport due to entrenched interests – is fascinating to play the numbers with. If one takes is a ZEOD, plug-in and fully charge the batteries in the garage, put – say – 15 litres of fuel in the tank, one would end up after a warm-up lap on the IC engine alone with a 670kg car and a potential 650hp. That’s 1kg/hp, for one lap…

‘Merde! Hé, Monsieur Bowlby, tiens, tiens!

Merde!’ away what you have done – it is always carry over and white sheet of paper. The engine is a base of last year. The way to do it, Porsche has a 4-cylinder which is the 8-cylinder of the Spyder cut in two. No one will start from something completely new.’

LE MANS 2014 59

NISSAN DIG-T R ENGINE

Good things come in

small packages The Nissan ZEOD is all about experimental technology, and the 1.5-litre, three-cylinder engine weighs just 40kg, produces 400bhp, and has pushed all the boundaries

By ANDREW COTTON

“We tried to define what best bore/stroke ratio would allow us to achieve our power”

60 LE MANS 2014

L

ate in January, Nissan unveiled the engine that will power the revolutionary Nissan ZEOD (Zero Emission on Demand) car at Le Mans this year. Built at Ray Mallock Limited (RML) in Wellingborough, UK, the engine’s design, weight and power have all been decided by extreme targets befitting of an experimental machine.

The engine is a 1.5-litre, three-cylinder direct injection turbo engine that weighs just 40kg, although with the turbo and exhaust it is 46kg, just over half the 90kg weight of the engine that powered the lightweight DeltaWing engine in 2012. Despite the light weight, the engine is

capable of producing 380Nm of torque at 7500rpm, or 400bhp, although its operating range will be closer to 360Nm of torque for efficiency.

The extreme weight saving extends to all areas of the engine, from the crankshaft, the block, the configuration and even the electronics. Electronic suppliers, for example, were selected by the weight of the product rather than their applications.

‘We were given a powertrain target weight,’ says RML’s director of powertrain, Arnaud Martin. ‘Considering that we are carrying two e-motors, a huge battery, and a gearbox which is capable of housing all those items, there

wasn’t much weight left for the engine. We needed to design the lightest possible engine. Secondly, we wanted some efficiency targets, so what would give us the most fuel efficiency? After that, packaging, because there is hardly any room, so we needed to fit it under the rear bodywork, and they were the three driving parameters to define what the engine needed to be, which was three cylinders, 1.5-litre displacement. We defined that using 1D simulation, trying to define what best bore/stroke ratio would allow us to achieve our power.’

RML’s team worked with precision engineering firm Capricorn to create the mono-

Extreme weight saving helped to bring the ZEOD engine down to an incredible 46kg fully dressed

LE MANS 2014 61

NISSAN DIG-T R ENGINE

The engine was designed with packaging in mind – the carbon plenum chamber fits around the bulkhead with a 4mm gap

block engine, which is mounted transversely and which uses 1.2 bar boost pressure. The ICE will have to run for 13 laps at Le Mans, using all the rear braking effect to charge up the batteries, which will then power the car for a 14th lap. This means that the internal combustion engine will therefore have to switch off for around four minutes, plus a minute in the pits.

‘The EV motors and the controllers are still linked to the cooling system of the engine,’ says Martin. ‘The target is to get 50 degrees water in EV mode, and 80 degrees in ICE mode. You basically keep your components warm. You have a cool down and warm up strategy while you are out on track and then you have switch over strategies between EV and ICE, which

allows you to go to EV while still cooling down the ICE until it is cool enough to be switched off. When you reach the end of the EV lap you restart it, warm it, and then at the end of the lap you switch over.’

The engine uses just 75 litres per minute of water for cooling all the systems, and the water is fed through two radiators. The right-side radiator cools the battery and the intercooler, while the left-side radiator is shared between the electrical motors, controllers, internal combustion engine, and gearbox.

RML has reached an agreement with French oil manufacturer Total to develop oils for all aspects of the car, from grease for the driveshafts to battery fluids and engine and gearbox oils, to reduce friction to improve overall efficiency.

LEAVING THE PIT LANE

I

f anyone ever wondered about the complexity of a hybrid car leaving the pit lane, they should be assured that it is a complicated enough issue.

Within the already tight engine bay is situated a clutch. As Arnaud Martin describes, this is no ordinary clutch application.

‘The clutch is there to disconnect the ICE from the EV and allow us to start things and stop things,’ says the Frenchman.

‘It is not a clutch connected to a pedal – it is connected

62 LE MANS 2014

to the ECU and it has its own pneumatic actuator. The way the car operates, it starts driving forward on electrical power. It reaches a calculated speed, and it releases the clutch to start the ICE. The clutch closes again, the ICE continues to run on idle, and you drive on EV. You let your ICE warm up, when you reach the end of the pit lane the ICE has warmed up, and then you start to switch from EV to ICE. That is the process on a normal track. We don’t use the ICE with cylinder cuts to control the

car speed, we just do it on EV. ‘Control for all that is done by our own software. The entire software to run this car has been written in-house. We had to find a platform because we don’t make our own ECUs and found a partner in MoTeC. We use their M1.

‘One lightweight ECU is controlling the whole car, so that means DRS, differential locking, we have a pneumatic locking differential so you can control a certain amount of slip, the ICE, and the brake balance.’

The packaging of the engine is dictated by the space available in the engine bay, and even the design has the same influences. The engine is tilted backwards by five degrees and the plenum chamber specially crafted to fit around the bulkhead of the car, and even then it leads to a 4mm gap between the two.

Weight savings

‘There is nothing from the DeltaWing engine because if you took the same concept, you would not be light enough,’ says Martin. ‘We worked at something new, something extreme to hit the 40kg of weight. As a result, everything has been re-engineered, and re-thought. The crank is totally different – there is no flange at the end to attach the flywheels. It is all done on the diameter of the pins, because as soon as you put on a flange, the weight increases.

‘There are a lot of things that we have never thought about using before, and as a result of this you could bore through the centre of the crank and remove all the material, and you are left with a hole, so at that point you do need to stop the oil coming out. But it can be done with aluminium or plastic bungs. If you remove those bungs you can see right through the engine.

‘The crank, with tungsten balance weight, is 5.8kg compared to the DeltaWing which was 8.3kg. It is shorter, but you could take any engine from four to three, if you cut a middle cylinder – that saves you 17 per cent of weight.

Even with the new crank concept we have saved 30 per cent, and it has been the same for the entire design.

nce

IT’S NOT JUST RADIO LE MANS

Radio Le Mans is one of the highlights of the Le Mans 24 hours. Featuring expert opinion, analysis, weather reports and pit lane reporting, thousands of British fans tune in to follow the action throughout one of the world’s greatest motor races. Behind the scenes, however, it is a mammoth effort to deliver a high-quality service, all year round. Even if it was just LePM Mans, Page Radio 1 12/11/03 2:44 Show Limited produces over 50 hours of live broadcasting that in 2013 attracted more than 11.5 million visits to the website: www.radiolemans.com The truth is; the Le Mans 24 hours is the jewel in the crown of the endurance racing year but, as far as RSL is concerned, it is complimented by smaller but no less sparkling gems throughout the season.

Many Le Mans fans don’t realise that the same team that put together their favourite radio station at La Sarthe are on duty at other events, all broadcast live and free at www.radiolemans.comand on FM at the tracks and often even on TV. Already in 2014, the same voices you fall asleep to have covered events in Dubai, Australia, USA, Italy, Belgium and the UK. Radio Show Limited has covered two 24 Hours races, two 12 hours races, two 6 hours races and two 4 hours races plus 22 two-hour weekly shows, adding up to over 150 hours of LIVE broadcasting from 6 countries on 4 continents – all BEFORE rolling in to Le Mans for the test weekend!

Sponsored by

So why is the Radio Show Limited team so much in demand? Clearly the passion, enthusiasm and knowledge of the presenters are very important.

But beyond that Radio Show Limited are the world experts in producing ‘integrated broadcast solutions’ suitable for use in multiple media outlets.

At the 24-Hour race in Dubai and at the 6 Hours of Silverstone the team were simultaneously; International live TV sound, local and global Internet radio and the track PA. Combined with significant cost savings over setting up several different operations, broadcasting this way provides a continuity of message for the event and sponsors that cannot be delivered any other way.

Underlining the relevance of this strategy, the FIA World Endurance Championship has appointed Radio Show Limited as their official English language broadcaster. The good news is everyone wins. The event and sponsors get access to a huge global audience on Radiolemans.com, TV companies get informed commentary originating trackside and the endurance racing fan – that’s you –get coverage from people who care and who are immersed in the sport.

For the thousands of fans that follow the Le Mans 24 hours, tune into 91.2 FM at the circuit, and for the millions online log on to the website, www.radiolemans.com. One of the highlights of the weekend is Racecar Engineering’s own deputy editor Sam Collins, who will be taking part in the race show on Saturday and Sunday.

NISSAN DIG-T R ENGINE

Top: the three-cylinder engine has undergone extensive testing and the team is confident that it will produce the magic 400bhp required Above: hollow centre crankshaft weighs in at 5.8kg – 2.5kg lighter than that used in the DeltaWing engine Right: a complete engine would fit into an overhead locker in an aircraft, such is its size. The team is confident of reliability

‘The detail in which we have examined ways to remove weight is mad. I had an engineer spend three days trying to remove a golf ball size of material from the cylinder head, just to be able to hit the target of 7kg.

‘We have implemented a way of removing

side and, with its light weight, the effect of the vibrating force is felt all the more. ‘It is quite violent, because the heavier the part, the less you feel the vibration as it is absorbed by the momentum of the powertrain,’ says Martin. ‘It is vibrating rather a lot. It doesn’t seem to be such an issue. So far, it seems to have withstood the test. The battery is vibration insulated, so it is not rigidly mounted in the chassis – it is able to isolate itself from the vibration.

The engine is mounted transversely due to the packaging issue. ‘In a confined space, we managed to fit the engine, gear cluster, differential, throttle body, clutch and two e-motors are housed,’ adds Martin. The turbo sits between the differential and the e-motors, creating an extremely hot environment. RML has created its own heat shielding which it believes works well.

The electronics for the entire car are serviced by a single ECU, provided by MoTeC but with software written in-house at RML by a codewriting specialist brought in for the project. This single ECU controls the DRS system, differential locking, the engine, and the automatic brake

“I had an engineer spend three days trying to remove a golf ball size of material to hit the target 7kg” lots of material from the side of the head and then we literally have 1mm of carbon covering it all and keeping the oil in. The plenum is as light as possible, so is mainly carbon. It is small in volume just to be able to fit it in the car, and it has a weird shape to be able to put it in the car.

There was no other place to put it, which is why the throttle body is above everything. You have to be uncompromising, and you finish up with nothing unnecessary!’

One of the key problems with the threecylinder engine is the vibration. By the nature of its design, the engine vibrates from side to 64 LE MANS 2014

balance as well as the EV systems (e-motor controller and battery).

While brake-by-wire systems, used in Formula 1 this year, are not allowed, there is an electronic element to the braking system.

By regulation, there has to be a hard link between the pedal and the brakes themselves, but with such a large amount of regeneration possible in the entire car, braking is proving to be a particular problem. ‘When you do regenerative braking, there is a point where you cannot recover any more energy,’ says Martin.

‘This is because the battery is full or you need to reduce the pressure because of a driver request in these conditions, you need to be able to shift the brake balance. We do that by a brake-by-wire system, which allows you to reduce the pressure on the rear brake without changing the pedal feel for the driver.’

There is also the issue of running the car on EV alone throughout the lap. The test car ran in EV mode alone for parts of the lap during the Le Mans test, while the race car, with more appropriate batteries, was being prepared for competition. Read about RML’s journey of discovery into electric racing in the next edition of Racecar Engineering.

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TECHNOLOGY – DATABYTES

How to deal with all the data Databytes provides engineerswith essential insights to help you to improve your data analysis skills, as Cosworth’s electronics experts share useful tips and tweaks learned from years of experience with data systems

S

The World Endurance Championship relies on a mountain of data being analysed quickly – and automated systems can help to decipher it

crutineering at the top level of motorsport can be an extremely challenging exercise – regulations for race series demand a lot, and with different manufacturers and engine suppliers to contend with, there’s a great deal to keep tabs on.

Looking at mechanical parts, aerodynamics and engines is difficult enough, but with advances in computer control and systems, it’s increasingly difficult to monitor the electronic side of things. In some series, this has become so impractical that a single-make electronic system is the only way to make sure everything is according to the regulations.

66 LE MANS 2014

The World Endurance Championship is a series where technical freedom is a big deal – fundamentally different technologies are allowed to compete on the same track at the same time, with excellent Equivalence of Technology. In order to monitor all competitors, each vehicle is fitted with a scrutineering data logging solution that consists of a main data logging and processing unit, data card reader and two distinct wireless telemetry solutions. Inputs to the main processor are from CAN devices and direct sensor inputs. The scrutineering system for each vehicle is checked before every race to make sure all the systems are working as expected. As well as having the

ability to send data wirelessly to the pits, the teams are expected to upload data from their systems throughout each race weekend. This applies to practice sessions, qualifying and race.

CAN-do attitude

The direct sensors are used to independently monitor drivetrain parameters as well as the conditions inside the cockpit. Strict regulations apply related to how hot it can be inside the cars, so teams must run efficient air conditioning systems, especially for races in warmer climates.

The sensors are all controlled, so that each team has an identical set of them. CAN buses are used extensively in the scrutineering

The data is not only looked at by individuals, but is also processed automatically to provide scrutineers with a quick overview

Figure 1: a simplified schematic of the scrutineering system CAN bus layout

Figure 2: example of how the main data logger calculates and then stores the maximum value of the cockpit temperature, which can then be sent to the timing system at the appropriate moment

system. There are two different buses, one is strictly for the race organiser to use and a second one connects the scrutineering solution to the vehicle control systems. A vast amount of channel data is passed on from the engine control unit on each car as well as other systems. Systems included on the CAN buses include torque sensor, fuel flow meters as well as GPS and the leader light controller.

The data gathered during each session is not only recorded in internal memory and on a removable card – there are also two wireless solutions for transmitting data.

One is a conventional telemetry system that continuously streams channel data back to the pits and there is also an innovative solution which provides small data packages through the track’s timing system.

In the latter case, each time the car passes a timing loop on the track, a short burst of data is triggered and data is sent back through the timing system transponder. This data is then presented on a live readout showing maximum and minimum values calculated by the main scrutineering logger.

Drowning in data

As you might have gathered, there is an awful lot of data presented by a system such as this, and it would take an army of people to trawl through all of it. However, the data here is not only looked at by individuals but also processed automatically to produce a traffic light system which allows the scrutineers a quick overview of all the cars in order to decide which ones need a closer look.

This scrutineering solution has been in use for several years now, and has proved its value throughout its course. The above is more an introduction of its main functions and does not open the lid on many of the other very clever bits that are used to detect any anomalies. The system has grown extensively since its incarnation, but is still nowhere near reaching its technical limits.

Produced in association with Cosworth Tel: +44 (0)1954 253600 Email: ceenquiries@cosworth.com Website: www.cosworth.com Figure 3: overview of a single class of cars – red, yellow and green indicate the status of each car. Green indicates that there is no issue or violation detected, yellow is when data is awaited, while red says a problem has been found LE MANS 2014 67

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