Racecar Engineering - Formula 1, All change for 2022

A digital supplement from the publisher of

Formula 1

All change for 2022 >> Porpoising explained >> Cost cap racing >> Sauber technologies

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FROM THE EDITOR

Divided opinions

F

ormula 1 rarely sees a paddock united. It happens, sometimes, but more commonly it lives up to its nickname; the Piranha Club. This is a place of no compromise, just competitive people with an insatiable hunger to win. The issue of racism has brought the paddock together. People have different ways of expressing their views and although some refused to take the knee, now accepted as a public symbol against judging a person by their skin colour, that does not mean that they don’t sign up to the basic message.

In other respects the paddock remains as divided as ever, and here we can talk about porpoising, and the FIA’s decision to step in to help address the issue. There have been rumours of favouritism, of course, as a former adviser to Mercedes’ Toto Wolff now works for the FIA, which mandated a change, which Mercedes already had ready, and which helped the Mercedes cars. It’s not hard to draw the line between the dots, whether that’s the right thing to do or not.

Personally I don’t think these dots should be connected. It would be extremely ill-advised for a governing body to show any favouritism to a competing team, and in Formula 1 where the Piranhas are always hungry, to do so would be called out immediately.

The point is that all manufacturers were party to the same rules at the start of their design process, all teams had equal opportunity, and all teams took the decision to design the cars as they did. The fact that some designs produce this problem is not down to the governing body. Others didn’t experience porpoising, or did so to manageable levels, so it was possible to cope with the phenomenon. The question follows that, if a car should suffer from such a characteristic, and that it affects a driver’s health to the point that some are complaining of long-term damage, is it the responsibility for a team, or a governing body, to fix it? This seems to be the crux of the argument; rivals say it’s team related, teams say that it’s governing body, as their rules permitted cars to be designed with such an attitude.

With the battle lines drawn in this matter, the FIA decided to step in, take responsibility for the long-term health of drivers, and offer a solution. It’s not an easy one as the measurements needed to provide the absolute oscillation figures that are deemed acceptable have yet

to be calculated and for sure there will be column inches filled as engineers and team bosses argue over the formula. However, there is a line in the FIA’s ruling that is probably more important than what it intends to do about addressing the porpoising issue: ‘…it is considered that all of a driver’s concentration needs to be focused on [the] task and that excessive fatigue or pain experienced by a driver could have significant consequences should it result in a loss of concentration.’

Countries all over the world are banning the use of mobile phones at the wheel as they cause distraction from the process of keeping the car on the road and not hitting inert objects. Will the FIA consider that the complex arrangement of buttons and switches on a steering wheel are a distraction? Will they consider talking to the team on the radio be a distraction?

For some drivers it clearly is. Some teams have to carefully time when they speak to their driver as they know that it could cost tenths of a second in lap time or cause risk to the car if communication is poorly timed.

Will the FIA consider driver comfort more fully in future, and mandate such things as controlling driver temperature, or cooled helmets to help maintain concentration?

Velvet-lined gloves? Where is the line?

Personally I doubt that they will go this far, but they have opened up a potential cause for argument. If a governing body steps in to address a design fault by a particular team, or set of designers in different teams, it has stepped beyond what might be considered to be normal for a governing body.

In the print edition of Racecar Engineering, Lotus engineer Peter Wright explains how excessive porpoising led to ‘flutter’ in the Lotus T80, an aerodynamic phenomenon that brings down aircraft if left unchecked. In the racing car it could not be fixed, and so the T80 was withdrawn from competition in favour of the older T79, compromising the team’s competitiveness but allowing its drivers to compete safely. That’s not an option this year, due to regulation changes, and the budget cap prevents real-world testing that might also offer a solution to porpoising. The solution, of course, is not clear cut and neither is the way to reach it. Welcome to the Piranha Club.

All manufacturers were party to the same rules at the start of the design process

Andrew Cotton, Editor

CONTENTS 04 AERO Understanding the changes for 2022 12 TRUE COST OF WINNING What is the effect of the cost cap on a team?

20 ADRIAN NEWEY One of the greats on F1 and the environment 26 SAUBER TECHNOLOGIES Behind the scenes at Hinwil’s engineering centre

38 CHASSISSIM AND PORPOISING 2 How to calculate your way out of aero trouble

XPB

32 CHASSISSIM AND PORPOISING How to identify bouncing, mathematical style

Racecar Engineering • Formula 1 2022 3

F1 2022 AERO REGULATIONS

Shape Shifters The shape of Formula 1 has changed for 2022 in a bid to improve the action on track by altering how cars interact in close proximity

By Stewart Mitchell

F

ormula 1 has made a revolutionary change for the 2022 season with one of the most extensive chassis regulation edits ever seen in the sport.

The new cars flipped the rules on their head by introducing previously banned design and aerodynamic techniques such as ground effect and cutting back on once heavy development elements such as the sidepods.

The 2022 design relies less on a surfacetype aerodynamic regime, whereby much of the generated downforce is by elements seen above the car, compared to 2021. The car’s downforce predominantly comes from tunnels under the car’s floor that interact with the track surface. This technique is known as the ground effect and is a far less sensitive aerodynamic regime than a surface-type one, producing less turbulence and a smaller wake.

The philosophy behind these regulations is to allow closer racing, with the potential for more overtakes by reducing the ‘dirty air’ rejected by a leading car.

The previous design saw cars lose 35 per cent of their downforce when running just 20m behind a car in front, measured from the lead car’s nose to the following car’s nose. As the trailing car closed in, the loss raised to as much as 47 per cent at around 10m distance behind. The 2022 car, which puts a heavy onus on the ground effect, reduces those figures to four per cent at 20m, rising to 18 per cent at 10m.

The journey toward the 2022 aerodynamic regulations started in 2017 when Liberty Media took over Formula 1. The new owner’s primary focus was to up the entertainment spectacle of Formula 1, and this rhetoric eventually filtered down to the technical regulations, which govern much of the ontrack behaviour of the cars in competition.

4 Formula 1 2022 • Racecar Engineering

Following the Liberty Media takeover, Formula 1’s in-house technical team started to look at the then current state of the sport aerodynamically, notably in car-following scenarios, which it had not addressed before.

It was not a priority, nor was it in the scope for teams to investigate car-to-car interaction in this way as they were only ever searching for performance on their own cars.

Formula 1 has a small technical team, with just five personnel in the aerodynamics department, along with a few other engineers on other projects such as power units, vehicle simulation and the like.

Of those five in the aerodynamics group, there are three aerodynamicists and two designers, all with Formula 1 experience. All came from teams in the series. This is a tiny fraction of even the least well-funded Formula 1 team’s aerodynamics department, so they certainly had their work cut out.

Technical resource However, although the department is small, it has enormous computational resource, collaborating with Formula 1’s technical partners, such as AWS, and can far exceed what teams can use.

Formula 1’s technical department also has a wind tunnel at its disposal, although it should be noted that most of the work it undertook in this programme was computational. This is because the investigations were predominantly looking at two-car interactions, and there’s no wind tunnel big enough to run two F1 cars at a sensible distance from eachother.

In the F1 technical team’s investigations, it became clear early on that there were considerable numbers at play in terms of performance delta from nominal to that

Following the Liberty Media takeover [in 2017], Formula 1’s inhouse technical team started to look at the then current state of the sport aerodynamically, notably in car-following scenarios

associated with car-to-car interaction, and cars were losing as much as half of their downforce in a close following situation.

That was a consistent theme in driver feedback since the 2021 generation of F1 technical regulations were introduced.

Drivers have often commented on the challenging feel of the car’s handling and system management, particularly cooling, when running close behind another car.

Once Formula 1 understood the magnitude of the problem, it set about deconstructing the cars to understand the elements driving the performance loss. The investigations showed two main areas of influence. Firstly, wake – the aerodynamic losses from the leading car and how they present to the next car. Secondly, the sensitivity of the following car to that wake.

No matter what, following cars are always going to be driving through disturbed airflow.

So, the two strands of development became improving (reducing) the wake from the lead car and making the car less sensitive to driving through a disturbed fluid.

Over the years since then, Formula 1’s technical team has been evolving various geometries to address those problems.

‘We’ve been very open minded about where to look, and developed and simulated many different options,’ says Jason Somerville, head of aerodynamics at Formula 1. ‘We even went back through history, looking at how car-to-car interaction was in different eras of the sport.

‘We found that there’s no magic era where cars were aerodynamically very downforce laden and also followed each other very well.

‘We never really saw that, certainly not in our research, though we were able to capture some features that are proven to be particularly bad in those conditions.’

The differences between the 2021 and 2022 cars are readily apparent, as is the scope for development, due in part to the abolishment of Formula 1 features in elements such as the bargeboards.

When presented with undisturbed laminar flow, bargeboards are incredibly strong performance devices, but severely inferior when shown a heavily turbulent wake.

So, these were components that Formula 1’s technical team highlighted as an area where they could reduce the sensitivities.

Ground effect Central to the 2022 car’s aero package is the shaped underbody with two large tunnels, which relies on the ground effect phenomenon to produce the highest proportion of the car’s downforce.

Ground effect works though Bernoulli’s principle, which states that an increase in the Racecar Engineering • Formula 1 2022 5

XBP Images

The 2022 car was designed by F1’s in-house aerodynamics team to generate better racing, both by reducing the wake produced and also the sensitivity to running in dirty air

speed of a fluid occurs simultaneously with a decrease in static pressure, or a decrease in the fluid’s potential energy.

So, by using a curved profile to the underside of the car’s floor, a low-pressure zone will occur with the highest downforcegenerating section at the throat (the section with the lowest volume / closest to the ground). The cross-sectional area available for air passing between the car’s floor and the ground then shrinks from the entry to the throat and expands behind it.

This causes the air to accelerate and, as a result, the pressure under the floor drops, while the pressure on top of the car is unaffected. Combined, this results in a net downward force.

‘This is the first time Formula 1 has changed the primary physics of the floor since it brought in the stepped flat bottom regulations in the 1990s,’ notes Somerville.

‘With a shaped underbody for 2022, the floor [has] become much more powerful and [is] a way of compensating for the lack of barge boards, which are particularly sensitive to driving through a wake. The result [is] a car much more resilient to dirty air.

‘Provided you’re not feeding the underfloor with front-wheel wake, it will then remain a powerful downforce-generating device across a broader range of operating conditions.’

Performance philosophy

The 2021 cars were sensitive to dirty air and drivers commented on how difficult they were to manage in following scenarios

‘The cars will [run] much lower rake in 2022 to get the sealing effect of the floor to generate the ground effect and work the tunnels in the floor in the most efficient way.’

The new, shaped underfloor also affects how the aerodynamic balance shifts when the car is subjected to wake.

The largest aerodynamic load contribution in the 2022 car comes from the centre of pressure of the floor, which is likely to be close to the middle of the car.

In contrast, the highest contributing aerodynamic devices of the 2021 cars comes from the wings located at each end of the car.

The change under the 2022 regulations is reasonably positive for the drivers, as stability will be more consistent in the racing scenarios the cars see on track.

‘We have done a great deal of work to try and ensure that the regulations haven’t got anything intrinsically unbalanced about them,’ says Somerville. ‘It’s inherent that you

The cars are running much lower rake in 2022 to get the sealing effect of the floor to generate the ground effect and work the tunnels in the floor in the most efficient way will see a lot of performance gains from the teams as they develop their cars, and that will have an effect on how the cars operate in dirty air.

‘For now, though, they are a lot less sensitive than the 2021 generation of cars.

In theory, when a car follows another, the aerodynamic balance will remain quite stable.

XBP Images

Naturally, a major focus for the teams ahead of the season was to try and exploit the new conditions. In terms of the performance to be gained with the 2022 regulation philosophy, combining the new floor and the new diffuser is a good few percentage points more powerful than the 2021 floors, with scope to be more powerful still.

‘The regulations are our end game in terms of our research model,’ continues Somerville. ‘It hasn’t had all the development and extracting performance from it at a competitive team’s level yet.

XBP Images

F1 2022 AERO REGULATIONS

The 2022 car’s downforce predominantly comes from a curved underfloor with tunnels that take advantage of Bernoulli’s principle to interact with the track surface 6 Formula 1 2022 • Racecar Engineering

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Simscale

F1 2022 AERO REGULATIONS

Controlling the Y250 vortices shed from the front wing was very influential in the wing and underside’s downforce-generating capability on the 2021 cars.

These are a thing of the past in 2022

It’s not like we’re losing a lot on the front or at the rear. It’s a relatively balanced loss to both axles, according to the research we’ve done.’

8 Formula 1 2022 • Racecar Engineering

The 2022 rear wing enables flow to roll off the top of the wing tips and narrows the expansion of dirty air from the back of the car

XBP Images

Like the bargeboards, the front and rear wings on the 2021 cars were very wake sensitive so they became more simplified systems for 2022, less susceptible to dirty air.

The 2022 regulations place less value on the front and rear wings in reaching target overall downforce figures, but the effect of the regulation changes here is that they should produce lower drag cars.

This, too, will provide more aerodynamic resilience in car-to-car interaction, as a lower drag car does not generate as much disturbed wake for the following car to drive through.

The 2022 regulations abolish the element-less 250mm section across the centre of the front wing in favour of wing elements that connect directly to the nose.

As such, the 2022 cars lack the Y250 vortex and its controlling devices, which have been present on Formula 1 cars since 2009. This has a significant effect on the downforcegenerating capability of the front wing and underbody flow feed.

‘The element-less 250mm section across the centre of the front wing went quite early on in our research because it was something that didn’t stand up to scrutiny,’ explains Somerville of that decision. ‘It was one of the first things that we found was very sensitive.

For the 2022 prescribed nose area, the way it interacts with the front wing gives room for interpretation and there will likely be different philosophies in this area across the grid.’

In the 2021 generation of the Formula 1 rules, an enormous development avenue for teams was to outwash the front wheel wake with front wing end plates, front brake duct furniture and bargeboards.

XBP Images

Lower drag wings

Rear wing tip vortices, seen here being shed from the left tip of the Alfa Romeo, had a huge influence on the size and shape of the dirty air shed from the 2021 cars. These are not a factor in 2022, and the hope is that the racing will be correspondingly closer

XBP Images

The 2022 regulations abolished the element-less 250mm section across the centre of the front wing in favour of wing elements that connect directly to the nose

These elements build up to create a car that still works aerodynamically in a wake situation and doesn’t create the disturbing outwash of the 2021 generation cars

These components contributed enormously to placing the front wheel wake wide away from the chassis, not disturbing the aerodynamic features further down the car. With that front wheel wake being pushed outboard, away from the sidepods and underfloor, it was very difficult for a following car to maintain a stable aerodynamic platform when passing alongside it.

The lack of bargeboards in the 2022 cars means the ability to generate outwash from behind the front wheels has gone, so teams have to find more subtle ways to manage it.

The 2022 car removes some of these outwash-generating tools, and implements a considerably simplified front wing design with a radiused transition to the end plates, specifically designed to avoid too much vorticity around the front wheel.

Certain mandated components on the front drums also avoid generating too much outwash behind the front wheels, while the introduction of wake-deflecting fins over the front wheels and wheel fairings further manage front tyre wake and outwash. The aim of these devices is simple: to improve airflow around the high disturbance area of the wheels, reduce lateral wake and make it easier to pull alongside a car ahead.

These elements all build up to create a car that still works aerodynamically in a wake situation and doesn’t create the disturbing outwash the 2021 generation cars did.

Simscale

Combining years of simulation and development shows the 2022-spec car to be far less susceptible to dirty air from a car in front than the 2021 cars. This simulation highlights how the car manages the flow

Racecar Engineering • Formula 1 2022 9

F1 2022 AERO REGULATIONS A further tightly constrained area by regulation for the 2022 car is the rear wing.

There is scope for teams to develop some elements to coincide with their philosophies, but the new regulations are far less free than the outgoing 2021 wing design.

The restrictions here predominantly focus on the tips, which coincide with the shape and size of the car’s rearward wake. The new design enables the flow to roll off the top of the wing tips and narrows the expansion of dirty air coming off the back of the car.

However, according to Formula 1’s technical design team, the regulations leave some unique upper profile design scope.

Additionally, the lower wing elements are quite open in terms of the regulations, which will provide a lot of development focus for teams to try and find the most efficient solution, particularly in integrating the wing with the flow coming out from the floor.

No sprouts ‘Consequently, there’s a region within the bodywork where teams can develop louvres and exits. It’s reasonably tightly governed so there should be no aerodynamic devices sprouting from various apertures.’

Comparing the 2021 car with that of the 2022 version, Somerville is confident about 10 Formula 1 2022 • Racecar Engineering

Under the 2021 rules, an enormous development avenue for teams was to outwash front wheel wake with front wing end plates, brake duct furniture and bargeboards. However, many of the outwash-generating elements have been removed for the 2022 car

XBP Images

DRS (the controversial drag reduction system) remains for the 2022 rear wings. The benefits that Formula 1’s aerodynamics department has found by reducing the effective downforce loss in following situations works against the following car’s aerodynamics in drag reduction. As such, the 2022 regulations enhance the need for some form of DRS, as Somerville explains: ‘Certainly, from our simulation work, we believe DRS is required.

‘Because the cars will be able to follow each other closer through the corners, it follows that the cars should be closer to each other on corner exit. But because there’s less of a hole being punched through the air by the lead car on the straights, cars need DRS to get closer there.’

Larger cooling louvres are permitted on the sidepods and engine cover, giving the teams some opportunity to play around with cooling configurations and, therefore, convergence of bodywork at the back of the car and the pressure delta at the diffuser.

‘We wanted to ensure we weren’t developing a set of regulations that were going to be enormously expensive, particularly with a budget cap in place,’ says Somerville. ‘We felt that although cooling louvres had come and gone over the last few years, the new regulations would likely favour reintroducing them as they are efficient ways of cooling. Plus there is no downside to them from the wake perspective.

Simscale

DRS to stay

The swept back new front wing end plates take inspiration from the aircraft world in reducing the vortices generated at their tips

the potential speed and stability. ‘I think the cars will generally be more stable and work very well through the high-speed corners,’ he says. ‘Where we left this car [in terms of regulations], the performance figures were somewhere south of the current generation of cars, in the knowledge that teams will subsequently find performance.

‘Even before the start of the season there was a lot of chatter about teams making progress. If you put the 2022 Formula 1 base car on the 2021 grid, it would be a few seconds off the pace, but I would have been very surprised if teams hadn’t extracted most of that back from their ongoing development ahead of the 2022 season.’

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LIVING WITH THE COST CAP

Cap in hand F1’s cost cap has forced teams to take a long, hard look at every aspect of their business, but is the end result a fairer, more efficient operation?

Photos: XPB Images

By Dieter Rencken

Mercedes and Red Bull set the pace in 2021 with their two lead drivers, but how much will they be affected by a cost cap for the 2022 season and will that allow the rest of the field to close the performance gap?

12 Formula 1 2022 • Racecar Engineering

Racecar Engineering • Formula 1 2022 13

LIVING WITH THE COST CAP

A

lthough F1’s sporting and technical regulations were largely rolled over from the 2020 ‘Covid’ season (around 60 per cent of the cars was carried over, although some of minor changes such as to floors and wings caused headaches) for practical and financial reasons, in 2021 F1 teams grappled with another variable, namely financial regulations – ‘budget caps’ in popular parlance – that were introduced after a protracted gestation.

Under consideration even before Liberty Media gained control of F1’s rights in 2017, the budget cap restricts spend in performance-critical areas and is intended to level the playing field. Three main areas are targeted: car design and development, component manufacture, and testing and race operations. Spend in these areas was restricted to $145m (approx. £107m / €128m) in 2021, reducing by $5m (approx. £3.7m / €4.4m) per annum in 2022 and ’23.

Ahead of the 2022 season, McLaren Racing CEO, Zak Brown, welcomed the reduction and glidepath. ‘With the spending limit reducing to $140m this year and $135m next, the new financial regulations present us – and the sport as a whole – with a fairer framework to compete by reducing the inevitable advantage of the biggest spending and best resourced teams,’ he said.

Exclusions to the cap are power units (at present), marketing / hospitality and team travel – to prevent cutbacks on standards of accommodation and flight classes – and car demonstrations and heritage (museum) operations. Crucially, despite drivers being major performance differentiators, their wages are also (currently) excluded from the cap, enabling better funded teams to gain distinct advantages in this quarter.

Equally, the top three salaries paid to team personnel are excluded, enabling wealthier outfits to recruit and retain top designers or strategists at the levels these command.

Still, the cap does go a way to redressing imbalances, although such are the facility and operational advantages accrued by major teams over the years that, according to AlphaTauri team boss, Franz Tost, momentum will carry them for three years, at least.

Kick in the Covid A complicating factor is that introduction of the (then $175m) cap was timed to coincide with F1’s ‘new era’ cars, planned for 2021.

Teams would have open budgets during 2020 under which to design their new cars, while having headroom to spend on campaigning their outgoing designs. The cap would then kick in during the first year of operation for the new era cars. All was sweet, it seemed.

But then came Covid, forcing F1 to reduce the planned cap by $30m and simultaneously roll over 2020 cars on cost saving grounds.

14 Formula 1 2022 • Racecar Engineering

While these moves arguably saved various teams (and F1?) from bankruptcy, the bottom line is they immediately hurled F1’s plans for an orderly transition off the patio on the top floor of the FIA’s building in Paris. ‘[The revised] cap cannot be achieved without further significant sacrifices, especially in terms of human resources,’ argued Ferrari team boss, Mattia Binotto, at the time. ‘However, if the current situation puts the existence of some of our competitors in this sport in doubt, and make it necessary to revise certain cornerstones, then Ferrari would be open to it.’

‘[The revised] cap cannot be achieved without further significant sacrifices, especially in terms of human resources’ Mattia Binotto, team principal at Ferrari F1

McLaren believes the cost cap will eventually put the emphasis back on engineering as the performance differentiator

But, as always in F1, there’s no gain without pain, as Binotto admits: ‘With the financial regulations, we cut some of the development and cut parts of our organisation. When you’ve got a cap, you need to limit yourself.’

For example, Ferrari took an early decision to cease aerodynamic development of its 2021 car in April, bringing its final upgrade package to Silverstone in July after transferring various aerodynamicists to the 2022 car earlier in the year. Under a ‘normal’ budgetary regime the team would have pushed through much deeper into the season, possibly even to the final round.

Overall, Ferrari says the cost cap has forced it to be more efficient, and to set higher targets for performance in all areas

That said, due to its internal values, Ferrari was fundamentally committed to reducing the human sacrifice where possible, with the benefit of also preserving its hard-won expertise, as Enrico Racca, Ferrari’s chief of staff functions, points out: ‘We first attacked any waste in production, especially to eliminate things we do several times because we were not able to succeed the first time.

‘The team’s head of chassis (engineering), Enrico Cardile, expands on that comment: ‘This was the first way we tried to reach our target, and we improved our simulation instead of using physical materials.

‘Of course, the budget cap is decreasing in the following years. We started on this path and we don’t know exactly where it will lead in the end, but for the 2021 car we focused on what we have explained, and in 2022 we have plans to stay in the budget, while trying to preserve our know how.’

The introduction of the cap gave rise to perceptions that teams, particularly the better funded ones, were squandering money and needed to be saved from themselves, but Racca counters this. ‘[Controls] were in place, but the budget cap [forced] us to set higher targets with cost of performance to ensure that when we decide to improve, or to invest money in another direction, or a specific design or material, it is done for performance that we recognise the merit of, because now the [cost implication] is part of the performance,’ he says.

McLaren technical director, James Key, believes it will take a certain amount of time for matters to settle in. ‘There will be some mismatches in facilities and things for a little while but, as things begin to coalesce between the various teams, I think you’ll begin to see much more of the performance engineering influence than we’ve been used to as a financial influence.’

Crash damage can be very costly, and at one point there was a suggestion of a compensation fund for innocent victims Racecar Engineering • Formula 1 2022 15

LIVING WITH THE COST CAP A measure of how tightly the financial regulations impacted team operations was revealed during the Monaco Grand Prix in 2021, when Mercedes F1 CEO, Toto Wolff, admitted the team was unable to conduct wet tyre tests aimed at 2022’s 18in tyre development due to budget constraints.

‘We are trying to make the budget cap, which is not trivial, and we couldn’t take the costs related to the tyre test and we wouldn’t have been able to send our mechanics on such a long journey,’ he said, adding the $1m costs in damage from Valtteri Bottas’ Imola crash last year had tipped the balance.

Brown and Tost, though, believe the caps are still too generous, despite budgets for the majors tumbling by as much as 50 per cent, the latter telling Racecar Engineering: ‘They are still too high. Teams just have to get used to [lower budgets].

Crash course ‘It’s a question of organisation, of management,’ notes Tost. ‘We were sitting together [in 2021] to plan for [2022], and everything we could put into consideration we put in there, which means there should be no surprises because we know exactly how much money we have for car parts. That includes modifications, upgrades and so on.

‘The only thing that could really cause problems are some very big accidents, expensive accidents, but we have some money on the side for this.’

To ensure employees grasped the full implications of the restrictions, teams staged

internal training courses for staff at all levels to reinforce savings awareness in all areas.

Still, considerable juggling was required to ensure maximum efficiencies, with savings in one area – for example, freight costs – benefiting car performance.

‘In my specific area, the main impact is the freight,’ explained McLaren executive director of racing, Andrea Stella. ‘This is an operational element of going racing that’s sometimes not in the spotlight, but actually is a considerable opportunity to generate savings and efficiency.

‘I welcomed the push given by the budget cap, because we generated efficiency in the way we ship stuff around the world, and I’m pleased with the way we were able to do that.’

Unsaid was that the savings facilitated additional spend in car performance areas.

Key stresses that McLaren has also been more cautious with its materials selection process. ‘There are some carbon fibres that are very expensive but very effective, and you sort of default to them knowing that your part will work as intended,’ he said. ‘[Not doing that] adds a layer of workload and complexity onto material selections, but it’s the right thing to do to reduce costs.’

According to various team sources, the cost of raw materials for a given car design are in the order of 10 per cent of the total, so substantially bigger cost savings are facilitated by simplifying the design of certain components, in turn reducing tooling requirements and manufacturing costs. Still, it is not a binary choice.

‘The search for [better] material is a never ending area of development, both for performance and for financial saving,’ confirms Ferrari’s Cardile.

‘I would not say we compromised our 2022 car by choosing cheaper materials.

What we did is push for a more rational approach by challenging past assumptions, or challenging some choices we would have [made] in the past by going into deeper analysis to check if a certain material was really needed for a specific application.

‘We now have another dimension that has to be taken into consideration,’ he adds.

Sporting changes This year’s rules also include changes to the sporting regulations as part of F1’s costsaving ethos, including a reduction to threeday race weekends, meaning teams need to pack the same workload into one day less.

This, too, has complicated the design task as the cars ideally need to be simpler to work on, in turn saving money.

‘You want to have a car that is slightly easier to operate, so you don’t find yourself up against time, or rushing, or having to complete the car in the morning,’ Key says, ‘which is never a healthy condition to be in because you end up missing other important aspects of the weekend if you’re constantly flat out with your car.’

Having worked for a several independent teams before joining McLaren, Key has seen first hand the effects of cost restraints, noting, ‘I’ve seen how much efficiency you can

Savings are being made in all areas, from material choice to freight to simplifying component design. But ultimately, for F1 to survive, it must retain its position at the top of the motorsport tree 16 Formula 1 2022 • Racecar Engineering

With their eyes on the prize(s), both Mercedes and Red Bull pushed development of their 2021 cars to the absolute limit, no doubt spending every last dollar of their budgets in the process

‘The only thing that could really cause problems are some very big accidents, expensive accidents, but we have some money on the side for this’ Franz Tost, team principal at AlphaTauri F1 team gain by thinking in a different way, trying to extract maybe 80 per cent [performance] out of 30 per cent of the cost.

‘There are definitely ways of working, which are kind of smart and to the point and prioritised and lean and kind of aggressive and agile. That’s where you need to be under the cost cap.’

Nevertheless, it was all a balancing act, with Key admitting that restructuring the technical department to meet the cap was no easy task. ‘We wanted the team to be internally recognisable, because it settled down into a rhythm of work with various groups operating very well together,’ he said.

‘So, we didn’t go through a massive restructure in the way the team operates.

We just looked at sensible directions. We needed to find efficiencies and found many.

Disrupting the team would have been counter to our longer-term objectives.’

Alfa Romeo (Sauber) team principal, Fred Vasseur, agreed. ‘Budget caps changed the mindset of F1, forcing the sport into efficiency mode.’ he said. ‘We have a [finite] budget and we have to make the best usage of [it].

‘It’s more the reality of business, back to the reality of life. You have to anticipate much more than before – what will be the impact of developments in terms of lap time? What issues could arise?

‘Also, you can’t launch parallel projects, you have to make a choice beforehand because you won’t have resources for both.’

The French graduate motorsport engineer says it will be crucial for teams to make the right choices throughout all stages of their design phases as they will no longer be able to spend their ways out of wrong decisions.

‘If a team takes the wrong way from the start [and] have to change some big component, this will penalise these teams for a very long period because they will need to spend a large part of the resources to change the monocoque, or the gearbox, for example, and [that will] take you to the limit of the cost cap,’ continues Vasseur, adding that major components could be rolled over to the next season provided the regulations remain stable.

The big question, though, is how Mercedes and Red Bull – both of whom pushed development of their 2021 cars to the maximum for as long as they dared in their quests for both titles – will fare once F1’s financial adjudication committee scours their respective accounts. While there are no suggestions that either team broke, or even bent, the rules, they surely ran extremely close to the limit.

‘We tried to extend the life of components to cut down on frequency of replacements,’ Red Bull chief engineer, Paul Monaghan, said in an exclusive interview with Racecar Engineering. ‘We sought to curtail the number of large aerodynamic updates we could consider for the seasons.’

Close to the limit Max Verstappen’s Silverstone crash [in 2021] effectively lost Red Bull an entire car, and a second of that magnitude could well have cost the Dutchman’s team two major upgrades, potentially torpedoing his title challenge. Indeed, teams have discussed ‘crash compensation’ for innocent victims of expensive incidents and, although talks went nowhere, that the topic was even tabled proves how close to the limit some teams are.

‘We didn’t want to spend money on just making spares replacements,’ says Monaghan. ‘We didn’t want to spend money on making parts that were benign in terms of Racecar Engineering • Formula 1 2022 17

LIVING WITH THE COST CAP performance, and so by careful diligence and Friday running we were able to evaluate that we could make fewer components. So, a few pennies [saved there].’

There’s no doubt the pinch was felt across the board, he says, with head count reductions and resource restrictions affecting design and development as much as research capability and manufacturing capacity. ‘So, you try to minimise the effects of that.’

Financial adjudication In terms of financial regulation, all teams are required to supply full documentation detailing all information pertaining to the operating year, as prescribed by the regulations, plus any declarations they may wish to table, by March of the subsequent year. The FIA reserves the right to impose spot checks at any point during the year.

All outsourced goods or services, whether obtained from another team or outside supplier, are subject to checks to ensure they are booked at ‘notional values’ to prevent teams from indirectly profiting from transfers from associated entities. So, for example, Red Bull could not supply sister team, AlphaTauri, with gearboxes for a dollar, or Mercedes have foundry work done at half price.

‘There’s quite a lot of checks going on,’ Alpine executive director, Marcin Budkowski, told Racecar Engineering. ‘We get regular visits from the FIA, regular requests for data and for information. Probably more than we expected, and at very short notice, including surprise visits to the factory.

That’s how it should be, though, and that’s how it should be policed.’

The acid test will not be whatever outcomes arise from the adjudication process, but rather what penalties should be applied if teams are found in breach of any area of the financial regulations. Penalties range from reprimands through monetary fines and time penalties to race suspensions and even exclusion from the championship, with the nominated responsible executive(s) potentially in line for bans from the sport.

Crucially, though, no prescribed tariffs exist, as is the case with sporting and technical contraventions: breaches will be subject to penalties as above being handed down on a discretionary basis by the adjudication committee.

‘The regulations don’t specify what the penalty is for [a specific] breach,’ says Budkowski. ‘The reason they are not defined is that as soon as you define a penalty, teams start to calculate whether [a certain interpretation] is the right thing to do or not.’

In other words, it’s a deliberate decision to prevent teams trading lap time gains against the cost of specified penalties.

The million-dollar question remains, though: how low can Formula 1 actually go, having initially fought tooth and nail against any kind of budget cap, and then rolling over and accepting $175m before signing up for a pandemic-induced glidepath from $145m to $135 over three years?

Teams could, if they desperately need to, survive on $100m (approx. £73.7m / €88.2m),

The acid test will not be whatever outcomes arise from the adjudication process, but rather what penalties should be applied if teams are found in breach of any area of the financial regulations as Williams (and others) did recently. If all teams raced to such levels, it would hardly affect the competitive order. It might even tighten it. But would it still be the Formula 1 loved by millions of fans, and recognised globally as the pinnacle of motorsport?

Ultimately, market forces will decide whether fans vote with their feet, and whether broadcasters and circuits remain willing to shell out eyewatering sums for a parade of increasingly dumbed-down cars.

This is Formula 1’s conundrum. Take budget caps too far, and the most capitalist sport on earth may well find itself paying the highest price for what, ironically, was intended as a saving spree.

In the interim, teams need to preserve sufficient budget to build and race their 2023 cars on another $5m less.

Red Bull was able to develop their 2021 challenger within the cost cap with intelligent planning. They sailed close to the financial wind, and one more crash might have scuppered their year 18 Formula 1 2022 • Racecar Engineering

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ADRIAN NEWEY

On the right track?

Thoughts on Formula 1’s new era from Red Bull Racing’s chief technical officer, Adrian Newey

By Dieter Rencken

T

he consensus throughout the Formula 1 paddock is that the 2022 technical regulations have seen the most significant changes to any rule set in the sport’s history. Mid-way through the season some teams are on top of the handling characteristics of their cars while others are still looking to achieve it, and have turned to regulators for help.

The journey into the new era of the sport was a bumpy one in every sense of the word, as teams faced a plethora of technical challenges throughout the testing weeks, primarily revolving around so-called porpoising – a bouncing phenomenon caused by the car’s inability to control its platform, stemming from extreme swings in downforce generated by the ground-effect aerodynamics. These issues first surfaced in testing at the start of the season, and there is no doubt that the solution is hard to find.

Racecar Engineering (RE) had the opportunity to sit down with Red Bull Racing’s chief technical officer, Adrian Newey, and ask his views on this latest era of Formula 1.

RE: First of all, can you explain the porpoising challenges?

Newey: ‘It’s a classic control theory problem.

When you have a set of aerodynamic regulations that allow ground effect, the closer the car gets to the ground, the more downforce it gives. If those vortices or structures, or whatever it might be, that give you that downforce starts to stall or separate,

20 Formula 1 2022 • Racecar Engineering

you lose downforce, the car springs back up and then the cycle repeats itself.

‘It’s nothing new. I believe the venturi cars of the late ’70s and ’80s had it. Certainly, plenty of Group C cars and so forth have struggled with it, including the current crop of LMP2s, so it’s a well-known phenomenon.

But while there’s nothing new to it, it’s perhaps unknown to many of the younger generation of Formula 1 aerodynamicists.’

RE: So, if it’s not new, why is it so difficult to manage, or even simulate?

Newey: ‘The first problem is wind tunnel models, generally speaking, are rigidly held.

And, if you hold the model of the car rigid, you won’t see the problem.

‘People in the past have tried to do transient movements of wind tunnel models, but that becomes a whole art form in itself.

Just as you have Reynolds number for the scaling of speed and scale, you have another thing called Froude number, which governs the frequency vs scale vs speed (the ratio of the flow inertia to the external field) that you have to move the model at to replicate what goes on on track.

‘If you have a car on the track bouncing along at five or six hertz, you have to go to a much higher frequency on the scale model, which creates dynamic problems. If you had a full-size model, you’d actually be able to replicate that, or at least replicate it far better than you can at the moment. But you would have to find some way of suspending the car

non-rigidly to do it. That would ultimately, or could ultimately, resolve the issue.’

RE: How difficult is it to actually solve the porpoising problem then?

Newey: ‘First of all, you have to understand the problem properly, which is not that easy in itself. Then after that, it’s about trying to come up with solutions that reduce the problem without losing downforce.

‘You’re in that classic performance vs comfort trade if you like.’

RE: Is this porpoising occuring at a different point of the car to the ones from the 1970s and ’80s?

Newey: ‘I was still at university in those times, so I can’t completely answer the question. But I think the phenomenon of flow structures breaking down will be exactly the same.

Where they break down on those cars didn’t

Adrian Newey is regarded as one of top engineering minds in the sport, winning no fewer than 10 Formula 1 constructors’ titles with cars he’s overseen

Photos: XPB Images

The first problem is wind tunnel models, generally speaking, are rigidly held. And, if you hold the model of the car rigid, you won’t see the [porpoising] problem

Red Bull Racing’s Adrian Newey and driver, Max Verstappen, on the podium after winning the 2021 Monaco Grand Prix

Racecar Engineering • Formula 1 2022 21

ADRIAN NEWEY

Red Bull Racing driver, Max Verstappen, preparing for a test run in the team’s RB18

have any significant vorticial structures as we have now. So I’m sure it’s different.

‘However, the basic principles are the same. These cars are aerodynamically reasonably complicated underneath in their flow structures. So, what’s actually going on, and where it’s breaking down, is going to vary from team to team.’

RE: Moving on, how do you find the new 18in tyres?

Newey: ‘Taking the new tyre parameters compared to those from the last few years, the rim diameter change hasn’t particularly changed anything because the sidewall behaviours are about the same. And it is the sidewall that tends to govern the stiffness and the characteristics.

‘They’re a little bit different, of course, and we’re still in the early days of understanding them. Still, they don’t obviously seem to be hugely different to previous generations’ Pirellis. Though they’re a lot heavier, of course.

Personally, I think the reason behind going to these big rims is to make it look more like a road car, which is a bit of a funny thing to do.’

RE: Does this lower profile tyre allow you better control of the suspension?

Newey: ‘As I say, the sidewalls have very similar behaviour, it’s just the tyres are bigger.

So the rim diameter has gone up, the tyre’s 22 Formula 1 2022 • Racecar Engineering

Much has been said about the porpoising effect due to the new ground effect aero package, not so much about the weight gain

overall diameter has gone up and the sidewall isn’t a lot shallower.

‘The bottom line is that the tyre spring rate is about the same, so there is very little change from a dynamics perspective.’

RE: How do you conceptualise the aerodynamic regime of these cars?

Newey: ‘I think the principle of trying to help cars to overtake by reducing the sensitivity of the following car to the one in front is okay.

And so, I think it will help [drivers] to overtake a little bit. I don’t think it will be a significant shift, but it will help a little bit.

‘In reality, the only thing I would say is that these are the most considerable aerodynamics regulation changes we have ever had since Formula 1 banned venturi cars at the end of 1982. So, if you’re going to have

In a few short years the weight limit has gone from low 600kg, and carrying onboard around 30-40kg of ballast, to cars that are 800kg and then some

such a significant regulation change, which inevitably will bring all sorts of other changes, it’s probably going to spread the grid of cars in the early seasons.

‘Let’s just say I think there are different ways it could have been done though.

‘The reality is you’ve now got cars at over 900kg start line weight. That’s well into what used to be considered heavy for Sportscars.

In a few short years, the weight limit has gone from low 600kg, and carrying onboard around 30-40kg of ballast, to cars that are 800kg and then some. And we’re all working like mad to try and get to that currently prescribed minimum weight limit of 795kg.

‘In short, the cars have got bigger and heavier and aerodynamically not particularly efficient because they have lots of drag. I think it is a bit of a shame that Formula 1 has gone this direction, especially because there’s the need and opportunity at the moment to go the exact opposite. Obviously, that wrong direction is the same sort of direction general automotive has gone recently, driving ever bigger and heavier cars all the time, and people obsessing about whether it’s battery or petrol. Well, the biggest single problem is the amount of energy it takes to move the damn thing, regardless of where that energy comes from. It seems Formula 1’s technical book doesn’t grasp that because, of course, the big car manufacturers don’t want to.

‘I think just getting the cars to the minimum weight limit is the big challenge of 2022 for a lot of teams, for sure.’

RC: There are discussions about adding 3kg to the minimum weight to try and make the job of weight saving less intense.

Does 3kg really make such a difference?

Newey: ‘Well, you have to remember that, very roughly speaking – and of course, it varies from circuit to circuit – you’re talking approximately 3/8 of a second per 10kg of car weight. So, that [3kg] weight difference equates to around 1/8 of a second.

‘I don’t have a benchmark figure for per kg saved, or per 10kg saved in terms of cost, but in truth it must be enormous.’

RE: How has the budget cap affected the whole development of the car?

Newey: ‘It is difficult for everybody. I totally agree that Formula 1 needs to avoid constant arms races and reduce costs. Whether you do it mainly by cost cap – which is obviously the route Formula 1 has taken – or you do it by other means is heavily debatable.

‘The reality is trying to do it financially is very complicated. So I’m sure there will be lots of acquisitions, and some people, as you can imagine, taking liberties in some areas.

‘And it’s going to be very difficult to police that down to the nth degree.

Sergio Perez gets to grips on track during testing with the team’s 2022 challenger

Racecar Engineering • Formula 1 2022 23

ADRIAN NEWEY

RE: In terms of designing the car, do you find it more of an engineering challenge to design a car to a regulation set than to an accountant’s directive?

Newey: ‘I don’t mind that because it’s just another constraint, and in a way it’s an interesting thing to have to take into account.

So that itself is okay.

‘I think what I fear is the kind of room for manoeuvre it potentially still leaves within the regulations in terms of fairness.

And also the fact that we, like many of the other teams, have unfortunately had to let some people go. That really doesn’t feel right.’

Red Bull Racing

‘Now, you could say, if you can’t police it, does the last five per cent matter? But the problem is we all have an enormous fixed cost. So the bit you have left over is the bit you can put into research and development.

Look at it that way, and those last few per cent do make a big difference.

‘And when we are in the position we’re in now, where just about every team on the grid has hit the cost cap, you can easily argue the cost cap is actually too low. In my opinion, it should be preventing an arms race amongst the top two or three teams, not bringing the whole grid down.’

The cost cap is making life difficult, so Newey says we should expect lots of acquisitions between teams as the new era progresses

RE: I know it’s early days, but overall, how does this era compare to previous ones?

Newey: ‘Nowadays, of course, we have this incredibly tight and lengthy rule book that very much constrains the shape of the cars. But, on the other hand, we have these

fantastic research tools, which means we can have a decent level of understanding.

‘Of course, you still get surprises, and the porpoising problem is a perfect example. But, by and large, the cars perform as expected, particularly once you understand them.

We need smaller, lighter cars that are more energy efficient. Unfortunately… with these new rules, Formula 1 has done precisely the opposite

24 Formula 1 2022 • Racecar Engineering

Adrian Newey (right) sits alongside Red Bull Racing’s team principal, Christian Horner

‘If there is a significant regulation change, it will not be too dramatic if the cars are well understood. It’s unusual to get nasty surprises.’

RE: Okay, so what would be your ideal regulations for a Formula 1 car?

Newey: ‘Light weight and aerodynamic efficiency are the two most important features.

Formula 1 often talks about road relevance, and it has had its place in popularising certain areas in the showroom. Carbon fibre trim is an easy example. And paddle-shift gear change.

Much of the plan view profile of the 2022 Formula 1 cars is prescribed, though there are many detailed areas of freedom that teams can exploit in line with their individual design philosophies

‘When the turbo era of the 1980s got underway, the automotive market saw more turbocharged cars produced. So, whilst there may not be any direct technical exchange, Formula 1 can certainly popularise trends.

‘Correctly, ecology is a massive subject at the moment, and Formula 1 can, and should, play its part in that. But there is all this debate about where your energy source should come from – whether it’s electrical, biofuels, synthetic fuel, hydrogen etc – and a lot of misinformation on this stuff, particularly on the electric side. People are starting to realise that the carbon footprint of manufacturing, and eventually disposing of, an electric vehicle is much higher than a petrol one.

‘But the assumption that the electricity that comes from wind or solar is somehow zero emissions is just not valid. You look at a wind turbine, particularly an offshore one, a tremendous amount of concrete goes into putting the structure in place. And concrete is one of the worst things for CO2 emissions.

‘There is also a lot of aluminium and copper in these structures, which are also very polluting materials in the manufacturing phase. So it’s good, but it’s not zero.

‘What nobody seems to be talking about is the amount of energy that is used to move the vehicle. So, rather ridiculously at the moment, manufacturers get a dispensation if they make their cars bigger and heavier in terms of their CO2 emissions, provided they make them less polluting at the tailpipe. I mean, where is the logic in that? It is driven by the government, which is lobbied by car manufacturers, which is very much like motor racing these days.

‘Some of the changes that happen in Formula 1 are a result of lobbying, too. So, in terms of where we need to get to, in my opinion, we need smaller, lighter cars that are more energy efficient. Unfortunately, at the moment, with these new rules, Formula 1 has done precisely the opposite to that.’

RE: Should we have a weight limit for all the safety stuff perhaps, and then have a maximum weight for the rest?

Newey: ‘Some of the safety stuff, of course, becomes a self-feeding problem. The heavier the car, the stronger it has to be. Some of [the weight increase] stems from power units, some of it from the safety stuff, and some of it comes from other regulations.

‘To me, it just needs a complete review.

The cars need to be quick, of course they do, because we all know that television has the effect of slowing it down and making them look less dramatic. Because of that, to look good on television, they have to be properly quick, which they are.

‘But there are other ways of doing that, which would be much more efficient than the routes F1 is currently pursuing.’

Racecar Engineering • Formula 1 2022 25

SAUBER TECHNOLOGIES

From a privateer race team to one of the biggest players in the industry, Racecar charts the evolution of Sauber’s engineering groups

By Stewart Mitchell

Axel Kruse, CEO of Sauber Technologies

Sauber’s wind tunnel is one of the best known and widely used of its type in motorsport today. This impressive facility now forms part of the newly formed Sauber Technologies

Images: Sauber Technologies

‘We’ve been pushing AM very hard because we recognise its potential for supply of the wind tunnel testing components and realising our designs in the real world before they go to final manufacture’ Axel Kruse, CEO at Sauber Technologies 26 Formula 1 2022 • Racecar Engineering

Forward thinking L

everaging a Formula 1 team’s engineering expertise and DevOps capabilities for other applications is nothing new. Teams up and down the grid have formed race team partner firms to sell their services to outside organisations for many years. However, this part of Formula 1 has evolved significantly over the past couple of years to accommodate the cost cap regulations and keep the staff’s amassed engineering expertise in house.

The Alfa Romeo Formula 1 team is run

by Sauber Motorsport, part of the Sauber Group based in Hinwil, Switzerland. The start of 2022 saw the birth of Sauber Technologies, a new company devoted to bringing Sauber’s

engineering innovation and Formula 1 mindset to businesses worldwide. Sauber Technologies incorporates Sauber Engineering and Sauber Aerodynamics, which have both been around for a while, strengthening their capabilities for customers across a broad range of industries.

‘In the past, we had three entities in the company: the motorsport pillar, aerodynamics and engineering,’ explains Axel Kruse, CEO of Sauber Technologies.

‘The engineering, which is the base of the Sauber Technologies group, came from our recognition of us having an excellent product in engineering expertise and being very strong in additive manufacturing (AM).

‘We’ve been pushing AM very hard because we recognise its potential for supply of the wind tunnel testing components and realising our designs in the real world before they go to final manufacture. With the introduction of the budget cap, it made sense to merge the aerodynamic and engineering capabilities as they are hand in hand. So, we created the Sauber Technologies arm of our company.’

There and back The evolution of the Sauber Group started in 1970 when Swiss businessman, Peter Sauber, founded Sauber Motorsport. After various stints in a multitude of racing Racecar Engineering • Formula 1 2022 27

SAUBER TECHNOLOGIES disciplines, from hillclimbing through to Sportscars, the team entered Formula 1 in 1993. After failing to make much of an impression as an independent outfit, Sauber sold the team to BMW in 2005.

It then competed as BMW Sauber from 2006 to 2009, scoring one victory.

Then, when BMW pulled out of Formula 1 at the end of the 2009 season, Peter Sauber bought his old team back again, and it was granted a 2010 entry.

The BMW Sauber project had resulted in a substantial increase in competitiveness for the team. Third party engineering work was always a strong pillar for Sauber, but its reliance on engineering output increased with the withdrawal of BMW’s funding. Today, Sauber Technologies is its own entity, entirely dedicated to third party business, though one of its biggest customers is Sauber Motorsport (currently the Orlen Alfa Romeo Formula 1 team).

Within the Technologies arm, the company has finite element analysis (FEA) and computational fluid dynamics (CFD) capacity, milling and other subtractive manufacturing solutions, additive manufacturing (AM) capability and wind tunnel services, able to run from full-size cars down to 50 per cent scale models.

Additive Industries’ modular and scalable MetalFAB1 system, designed for integrated and automated production with metal powder bed fusion technology using four lasers

Clear vision ‘With this capability, alongside our consulting within those areas, we can support companies with a clear vision who want to execute their programme from taking a blank sheet of paper and ideas to full production,’ explains Kruse.

Sauber Technologies’ additive manufacturing capability was born out of the high demand for test parts to be made quickly and accurately. When BMW bought the Formula 1 team, it brought with it a significant budget. The Sauber Group management therefore put together a plan for team to improve efficiency across all its operations. Part of that drive was to stop outsourcing the production of wind tunnel components. That desire saw Sauber build up its additive manufacturing department internally, initially for plastic parts for Sauber Motorsport produced via stereo lithography (SLA) and selective laser sintering (SLS) techniques.

‘Early on in our additive manufacturing journey, we discovered some parts on the full-scale car we wanted to print, but the material was not available in the quality we needed,’ notes Kruse. ‘For example, for the Monaco GP, you need the front brake ducts to have the maximum ducting because of the high number of braking zones and the low flow field velocity through the front braking system. But you only need this configuration for that race once a year.

28 Formula 1 2022 • Racecar Engineering

After an AM part is manufactured and processed, it is laser scanned and compared to the original CAD file to ensure no discrepancies

Often, additive manufactured parts will be hand finished by operators with subtle surface techniques used on external aspects

‘In the past, we built Monaco GP brake ducts from virgin carbon fibre. The process included positive and negative laminating followed by milling, and then you have six sets for the two cars for that weekend. The design would evolve for the following year, so the tooling would be a waste. We wanted to print them because it’s a one off, but we had to find a material temperature resistant enough to do that. So we developed our own.’

The company’s proprietary HiPAC SLS material was the result. It is based on a carbon-reinforced polyamide 12 and offers high mechanical properties and dimensional stability, with low water absorption compared to other polyamides, making it barely affected by moisture.

Outside of the niche Monaco brake duct application, Sauber saw a market demand for such a material in different applications.

‘So, we ramped up the plastic AM capacity to supply the needs of the Formula 1 applications [wind tunnel testing and some additional parts on the car] and third-party market demand,’ Kruse explains.

‘We bought six SLA and six SLS machines to cope with the demand as it came in.’

Material composition With Sauber an early adopter of the then new AM techniques within the Formula 1 fraternity, it also pioneered material composition, alongside powdered material manufacture. The powdered material evolution has been rapid, although many of the exotic materials used to exploit performance in high-end industries are banned in Formula 1.

On the plastic AM side, Kruse says there’s always something new coming. For example, Sauber Technologies is currently doing a lot of work with carbon fibre-reinforced PA12 material. The reason is that it’s so versatile, and engineers can manipulate its composition to fulfil a wide range of different demands.

Its most significant strength is its high-

temperature stability when compared to other AM plastics – up to 170degC. The fibre orientation cannot be stipulated in manufacturing fibre-reinforced polymers produced using current AM. That means engineers cannot optimise the internal structure for the number of fibres and load directions the part will experience during operation. However, the part’s shape can be designed to be more optimised for the application, thanks to the almost limitless construction freedom of AM. That means some of the strength lost from the lack of fibre orientation in the material structure can be compensated for by good design.

‘After many trials, you learn what is the right number of fibres over that part,’ explains Kruse. ‘Everywhere across the part has the same density of fibres, and so the same strength, because you can’t orientate them.’

Metal AM Soon after the plastic AM side of the business took off, Sauber began investigating the potential of metal additive manufacturing.

At the time, the technology was immature, and a lot of expertise was required to make parts successfully using this technique.

Consequently, Sauber decided it needed a partner for this venture, which it found in Dutch firm Additive Industries. Today, they are a principal partner to Sauber Technologies, providing a series of metal AM technologies, including the machines and the software to produce metal AM components. Finding a partner in Additive Industries also saw the company install four metal printers to print titanium, specially strengthened aluminium and stainless steel.

Metal AM machines work with a vast array of powdered materials, so improving the performance of AM-produced parts is down to the laser parameters and environment around the part during production.

‘We are focusing on the metals usable for Formula 1 in metal AM and exploiting what we know for third party business,’ notes Kruse. ‘Formula 1 wants to keep a stable bill of materials. The management does not want a situation where things like beryllium are used again, and the costs ramp up. They have a strict catalogue of what is available to use,

‘Metal AM was a huge shift in capabilities for the Formula 1 application as a vast number of components on the car could now be printed’ Axel Kruse so there’s little point in exploring anything else outside those specified materials.

‘Metal AM was a huge shift in capabilities for the Formula 1 application as a vast number of components on the car could now be printed.

‘This was a massive milestone for the technology and us as a supplier of these elements, but there was still a steep learning curve to climb. Early on, there was quite a disparity between the performance of an additive manufactured part compared to a part subtractive manufactured from a billet of material. To further optimise the AM components, we needed to develop our design approach for manufacture with AM in mind. Our technology and FEA programming has evolved to the point where we are designing in a completely different type of way to accommodate the potential of AM.’ Additive manufacturing has a series of positive knock-on effects outside of the lack of material waste and the potential to optimise shapes stemming from the freedom in design it offers. It allows users to reduce considerably the number of milling machine cutters required, and the produced parts are often lighter, so cheaper to transport. Engineers can also now achieve integrated features with four or five functions within one AM component, rather than producing several parts from subtractive manufacturing that go together into an assembly. As such, part count on a given system can be reduced, meaning storage departments can reduce their capacity, too.

Finally, lead times for AM components are significantly less than other manufacturing techniques.

Techniques for AM

Titanium additive manufacturing is a major development for Sauber Technologies. Here’s a post-turbine exhaust part for a contemporary turbocharged, 1.6-litre, V6 Formula 1 engine

When the part is being layered during the AM process, the first layer will heat cycle more than the top layer if the build chamber environment isn’t properly managed.

Making sure the heat distribution is even throughout the part, therefore, so there’s no additional stress placed upon the first layers compared to the top layers is critical for part performance when it goes into service.

Racecar Engineering • Formula 1 2022 29

SAUBER TECHNOLOGIES ‘We’ve worked very hard to develop working practices for AM throughout this journey,’ remarks Kruse. ‘Working out what the right chamber and build platform temperature should be when you start is critical to how the layers bond during construction. And this process is different from material to material. We print several millimetres before the formation of the main structure begins because we cut the part off the build platform, and this support structure will take the heat away from the part and into the platform.

‘If you are building a complex structure, any overhanging or long lateral forms must be supported by structures underneath them.

We design the manufacturing process so the machine prints these support structures, and they have several roles. Their primary function is accurately mechanically supporting the part, but they must also effectively draw heat away from the component body, and also need to easily break away, or grind away, from the main feature in post-processing.’

The secondary and tertiary roles are more intensive in engineering than mechanical handling. ‘We carry out in-depth finite element analysis and simulation to identify how the part’s mechanical and thermal stress comes out through the support structure, and ensure when we cut it out that it’s not going to damage the part,’ continues Kruse.

‘Proprietary design techniques are used to ensure the heat from the build follows a given support structure path away from the part body better than through the part itself.

‘We simulate this in the design programme we use: where the support structure contacts the part, where the heat goes, where the mechanical forces go, and the interface between the support structure and the part is defined extremely accurately. Then we will optimise that

Sauber Technologies has invested heavily in AM technology in recent times. Shown here is its four stereolithography (SLA) polymer additive manufacturing machines

30 Formula 1 2022 • Racecar Engineering

to ensure the part can go into service as soon as possible after the build.

‘Additionally, using the build platform most efficiently is critical, because the money you’re spending is mostly machine running time. So, you have a platform size with several parts and different structures, which should not interfere with all the others. Yes, this is the tricky thing.’

Engineering consultancy Despite the manufacturing side of Sauber Technologies being a significant element of the business, the largest growth area for the company has been in engineering consulting.

In the beginning, the consulting arm was around 30 per cent of the output, and now it’s over 50 per cent, with far more customers.

‘The engineering, consulting and project management is growing very fast,’ says Kruse.

‘Very often, these projects are combined with the AM technology or wind tunnel facility, making our company a one-stop shop for all the required parts of a project.’

Of the consulting side of things, Kruse says the competitive edge for the engineering side of the Technologies group is its design for AM capabilities. ‘I think it’s a big move, especially when talking with the designers, because they often think in structures they know. But when designing for AM, you must come from the other side, focusing only on what is necessary for the specification of the part, not thinking about what it should look like. This is a different type of thinking. It’s also a lot of learning to give the designer confidence that we can do that.

‘In Formula 1, speed of learning is everything, and we have a very high learning curve. To maximise this, we have dedicated programmes on the AM machines to do pre-development for the Formula 1 team, including testing. We have

‘We have invested a lot of money in test facilities and equipment to carry out tensile strength tests and finished part tolerancing to verify the [AM] material and its properties’ Axel Kruse invested a lot of money in test facilities and equipment to carry out tensile strength tests and finished part tolerancing to verify the material and its properties.

‘Because the AM techniques we use have a powder bed and are created by melting that powder in layers, you must make sure everything is consistent from top to bottom, and you have to test it. When we started, the testing methodology for this technology was not available. We had to develop it ourselves.’

Wind tunnel Perhaps the most well-known part of the Sauber Technologies group is its wind tunnel facility. It boasts cutting-edge technology for all relevant aspects: wind speed, size of the test section, rolling road, model motion system and data collection. The tunnel has a maximum tube diameter of 9.4m and is designed as a closed circuit, measuring 141m in length (without the test section). The overall weight of all the steel elements, plus the fan housing, comes to 480 tonnes. The single-stage axial fan with carbon rotor blades is state of the art.

At the heart of the wind tunnel is the test section. It is generously proportioned to provide representative racing conditions for precise results. Testing with a full-scale racecar is possible and consequently it is used by many third-party clients.

However, current regulations ban full-scale testing in Formula 1 and some other racing series, so F1 exclusively uses 60 per cent scale models for wind tunnel testing work.

The entire measuring platform can be rotated in the Sauber Technologies tunnel to allow test models to be exposed to the airstream – at anything up to 288km/h – at an angle of up to 10 degrees. The platform features a rotating steel belt that runs in sync with the airflow to simulate the relative motion between the vehicle and road, and has load cells mounted underneath to measure wheel loads. This gives a more accurate picture of the dynamics and includes the influence of the rotating wheels, enabling engineers to measure aerodynamic loads in different states.

‘We put a lot of emphasis on the tunnel facility to develop it to a very high standard,’ remarks Kruse. ‘We pride ourselves in being state of the art. This has really developed our relationship with the FIA and its racing championships. The tunnel size means we can prepare full-scale testing, ideal for understanding real world behaviour. We can also do all the BoP testing and validation with real cars, and we have always had an open mind to having third party business here.

‘As a supplement to wind tunnel development, or as a substitute for complex tests in which engineers can try out many possibilities and options, CFD is the solution for working out results quickly and efficiently. We operate a computer centre in the wind tunnel facility, which allows us to perform numerous calculations

The wind tunnel’s single-stage axial fan with carbon rotor blades can power the air speed up to 288km/h and uses 3000kW at full load

in a short time. In addition to efficiency, the correlation between software and reality is also a major focus of our work.’

Unconventional thinking The high standard of correlation, combined with the precise and flexible testing options, make the Sauber wind tunnel the most used of its kind in the world. Kruse explains why: ‘In Formula 1, the boundary conditions are always changing. This calls for unconventional thinking to gain a competitive advantage.

To support this process, we have developed a series of complex measurement and control systems and integrated them into our wind tunnel environment.

‘We have also designed flow switches controlled by changes in air velocity

At over 141m in length and with a maximum tube diameter of 9.4m, the Sauber wind tunnel is a colossal structure, capable of accepting full-scale vehicles as well as the 60 per cent scale models required by current F1 regulations

‘In Formula 1, the boundary conditions are always changing. This calls for unconventional thinking to gain a competitive advantage’ Axel Kruse and developed many other mechanical and fluid-based testing systems.’

Naturally, the wind tunnel testing protocol changes depending on application, too. ‘You can run full scale, high sophistication and development rates for things like Le Mans Prototype with tyre, suspension and powertrain measurement active,’ explains Kruse, ‘but sometimes it doesn’t make sense to instrument everything to the nth degree.

So, you design the testing environment to gather all the necessary information.

‘For standard equipment, or GT-type racing, especially those running under BoP, LMP levels of instrumentation are not needed.’

It’s clear that the Sauber Technologies arm of the Sauber Group does not still, which is why it continues to grow. And with it, so does the Orlen Alfa Romeo Formula 1 team’s performance on track. That’s not a coincidence, but the result of a dedicated engineering operation with state-of-theart facilities that leverages the extensive talents of its crew. That’s where the competitive advantage lies these days.

Racecar Engineering • Formula 1 2022 31

SIMULATION

The porpoise effect It’s nothing new, but what exactly is it, and how do you deal with it?

XPB Images

By Danny Nowlan

Porpoising has been one of the main topics of conversation amongst professionals and lay persons since the new generation F1 cars hit the track earlier this year, but Danny’s seen it all before

M

otorsport-wise, one of the key problems that has emerged from early season testing of the new generation Formula 1 cars is so-called porpoising. Given that myself and ChassisSim customers have dealt with this to some degree over the years, I’ve had a wry giggle at the number of lay punters out there who think this is a new thing.

Porpoising has been around for a good while now, and is one of the things that’s always lurking around the corner if

you run a high-downforce racecar. In this article we’ll discuss what it is and, more importantly, how you can deal with it.

First things first. If you insist on running a high-downforce racecar that is passive, the risk of porpoising is the price you pay.

It doesn’t matter whether you’re running ground effect tunnels or flat bottoms, if you have either very badly conditioned aerodynamics, or a badly tuned spring / damper package, it will make its presence felt at some point.

What porpoising refers to is low-tohigh frequency oscillation in the pitch mode of the sprung mass of the vehicle.

To illustrate this, Figure 1 shows how downforce is generated on a racecar.

The two ways you generate downforce are by accelerating air under the car or over the rear wings. The latter is tied quite closer to the former, but we are nitpicking.

When a car is prone to porpoising, from an aerodynamic perspective you have two culprits. Either the front wing / splitter

Porpoising… is low-to-high frequency oscillation in the pitch mode of the sprung mass of the vehicle 32 Formula 1 2022 • Racecar Engineering

Fig 1: How downforce is generated on a racecar

From a mathematical perspective, what drives this is the aerodynamics having a fundamentally destabilising moment on the car Equation 1

stalls, or chokes the floor to the under floor. Alternatively, the rear gets too low and that stalls the diffuser. What happens in both cases is that when either the front or rear gets critically low, the discontinuity that occurs kicks in and sends the relevant end back up. Downforce then kicks in and pushes the relevant end back down again. This up / down motion can set up a high-frequency pitch oscillation that can be deleterious to both the car itself and performance. During my career I’ve seen both effects make their presence felt, so it’s not limited to one situation or the other.

There are some other interactions what will induce porpoising as well. Typically, a badly conditioned spring / damper package.

The worst offender I tend to see is a third spring arrangement that hits a bump rubber that’s effectively a brick. This then sets up an oscillation that is very difficult to manage.

Another popular culprit is when you have a large amount of downforce combined with a massive aero balance. Both of these on their own are bad enough, but combine them and you are quickly in a world of hurt.

From a mathematical perspective, what drives this is the aerodynamics having a fundamentally destabilising moment on the car. This is summarised in equation 1, taken from my book, The dynamics of the race car.

Now, I’m not going into all the terms of this equation because it would distract us from the purpose of this article. However,

I want to bring your attention to two things. Firstly, the spring and damper settings described by the k and c terms have a fundamentally stabilising effect on the sprung mass, particularly in pitch.

The aero terms are described by the derivatives of F and M respectively, and fundamentally destabilise the sprung mass. How big these terms are will dictate what you can and cannot do about it.

Problem solving The first step to solving this problem is having an aero map validated from race data.

This is a do not pass go, don’t collect your $200 point. If you haven’t got that, you need it, and it should look something like Figure 2.

Racecar Engineering • Formula 1 2022 33

SIMULATION Without something like Figure 2, you are not in the game. That’s the very reason we at ChassisSim went to a great deal of trouble to develop and evolve the aero modelling toolbox. I also hammer this point home in the ChassisSim bootcamps, and the seminars I give, because it gets results. Simple as that.

Once you have this, you have the tools at your disposal to start addressing the problem.

Before we begin, though, there is a common misconception that, unless you have inerters / mass dampers and front and rear interconnected springs, you can’t deal with this. I can tell you from personal experience that is nonsense, but the best way to dispel a myth is by example.

Fig 2: A suitable aero balance map derived from race data

Lead by example To illustrate this, I have recently been working on a hillclimb car called an Empire Wraith, as shown in Figure 3.

What made my job a lot easier in this instance is the aerodynamics of the car were done by Willem Toet. The car is a masterpiece of the art, with very well conditioned aerodynamics. That said, there were still issues in terms of the stability of the platform, which is where I was called.

I should also add, in terms of suspension for this car you are dealing with a front monoshock and twin main springs. The accompanying damper package was nothing special, so it was just a matter of harmonising the components.

The first step in bringing this project together was the ChassisSim shaker rig toolbox. A typical output of which is shown in Figure 4.

Fig 3: The Empire Wraith hillclimb car

34 Formula 1 2022 • Racecar Engineering

The mechanics of how to drive and use this I have covered many times before, so the quick ‘elevator speech’ version is the contact path load (CPL) variation is a direct measure of your mechanical grip. You are then watching the heave mode (the variation of vertical load of the chassis) and the cross pitch mode, which is the pitch

response when you have a heave input.

The telltale sign that you have a porpoising problem, or at the very least have pitching that needs to be controlled, is when the cross pitch mode is very high. This is exactly what we see with this car, illustrated by the black trace in Figure 4. Fortunately, for this car, the latter was the case.

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SIMULATION

While porpoising is certainly a problem that needs to be taken seriously, it can be dealt with, or at least mitigated, using off-the-shelf components An additional challenge faced in this example was that, in addition to its high downforce levels (a CLA well north of three, in a very light car), the car was running on some exceptionally bumpy circuits, which meant you couldn’t go to insane spring rates.

We therefore had to be very creative with the damping. Here, the ChassisSim dual rate damper model is your friend, and this is illustrated in Figure 5.

The important thing to understand here is the low speed section controls the sprung mass and the high speed filters out the bumps. With this car, we needed to pay very close attention to the bypasses, and the relations between the low speed and high speed damper rates. In particular, since we had to go to a softer spring rate, we needed damping ratios north of 0.7 in the low speed. Compromises like these are the dance you need to engage in and, while the dual rate damper model is far from perfect, it’s a powerful tool to help you sort through the options.

And the tuning process you have to go through will be very enlightening. The spreadsheet of this is shown in Figure 6.

Since this is a live racecar, I have redacted the specific set-up information, but the take away is right down the bottom. Note the increase in the rear spring rate and the reduction in the CPL and cross pitch mode. This is what happens when you have a proper aero map (in this case generated from CFD) that has an effect on the shaker rig calculations. This should lay to rest one of the primary criticisms of shaker rigs – that you always soften the car. This was not the case here.

Of course, the ultimate proof is in the pudding so, if you want to see the result, the last 20 seconds of this YouTube video speaks volumes: youtu.be/DTWh9XyL1yU You will note how stable the platform is.

Summary The point of this case study is to show how far down the road you can get toward addressing porpoising using straightforward suspension elements. To summarise, here’s a

Fig 6: Tuning process for the dampers

36 Formula 1 2022 • Racecar Engineering

Fig 4: ChassisSim shaker rig toolbox

Fig 5: The ChassisSim dual rate damper model

quick porpoising cheat sheet: • Know the car’s resonant frequency, so you can stay away from it.

• Don’t worry (within reason) about being aggressive with damping.

• Don’t fall into the trap of no bump and plenty of rebound. That is the last thing you need if you are suffering porpoising effects.

• •

When the bump rubber engages, make sure it is continuous and smooth.

Finally, a tool like the ChassisSim shaker rig toolbox is invaluable.

In conclusion, while porpoising is certainly a problem that needs to be taken seriously, it can be dealt with, or at least mitigated, using off-the-shelf components.

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SIMULATION

The porpoise effect

Part two

A case study approach to understand what drives this phenomenon

XPB

By Danny Nowlan

At Barcelona Ferrari’s 2022 car suffered from porpoising, but Carlos Sainz (left) and team-mate Charles Leclerc (in car) are now proving competitive following fast work from their engineers

I

n the first article on porpoising, I gave a broad overview of what the effect was, and a case study of how the approaches to dealing with it were applied to a highdownforce open wheeler.

What that article lacked, however, was detail, because I was talking about a live racecar and was unable to share any particulars about the programme.

So, to address this, I have taken one of the ChassisSim templates and radically increased the downforce so I can give you some actual numbers and a quantitive case study. Along the way, I’m pleased to say a lot was learned, in particular the limits of what you can actually do, and what you should be thinking about.

This is what we’ll be discussing in depth in this article.

First things first. While my initial comments on porpoising still stand, one thing I was remiss in not mentioning was what you can do about porpoising is highly dependent on the relationship between the platform and tyre stiffness. To understand why this is, let’s refer to the quarter car model of a car’s suspension, as shown in Figure 1.

The relationship between tyre spring stiffness and platform stiffness will dictate what you can do about porpoising. In particular, equation 1 explains it.

K eq =

Fig 1: Quarter car model of the car’s suspension

K B × KT K B + KT

% x B = 100 ×

KT K B + KT

(1)

Where, Keq = equivalent spring rate of the body and tyre spring combined KB = spring rate of the sprung mass KT = spring rate of the tyre %xb = percentage of movement of the sprung mass The vital point to note here is your absolute limit is the spring rate of the tyre, particularly if the tyre spring rate is too low. If we cross reference this to Figure 1, you’ll see you can do everything you want with the body spring and damper but, fundamentally, there is little you can do to solve the problem.

The parameters are mB = mass of the sprung mass (kg) mT = mass of the unsprung mass (kg) KB = sprung mass spring rate (N/m) CB = sprung mass damping (N/m/s) = tyre spring rate (N/m) KT

What you can do about porpoising is highly dependent on the relationship between the platform and tyre stiffness 38 Formula 1 2022 • Racecar Engineering

So, let’s now talk about the racecar particulars. These are outlined in Table 1.

To add a bit more colour to this, Figure 2 is the CLA front and rear ride height map.

One thing to note here is that the values in these maps have been normalised to aid the illustration. The actual numbers are multiplied by the CLA number in Table 1.

Aero oscillation The real challenge in setting up this car is manifold. Firstly, there is quite a bit of aero variation here. While not porpoising in the strictest sense, this car will be prone to a lot of aero-induced oscillation.

Secondly, the car is producing peak downforce between zero and 8mm of front ride height. This is going to dictate a very stiff front heave spring / bump rubber package.

Table 1: Example racecar particulars Item CLA Aero balance on front axle Car mass Weight distribution at the front Front rh Rear rh Front spring rate Rear spring rate Front tyre spring rate Rear tyre spring rate All motion ratios front and rear Circuit

The first challenge in resolving the set-up for the racecar is to figure out what the limit condition is The first challenge, then, in resolving the set-up for the racecar is to figure out what the limit condition is.

From some preliminary simulation work I did, the mid-corner speeds are typically 200km/h and end-of-straight speed is 300km/h. For the mid-corner speed, equation 2 is what we have in terms of downforce requirements.

td f =

6 45% 800kg 45% 70mm 80mm 270 N/mm 350 N/mm 220 N/mm 270 N/mm 1 Eastern Creek

Fig 2: Front and rear ride height map

2 × k tf

6176.04 N 2 × 220 = 9.09mm Faero _ r td r = 2 × k tr =

7548.54 N 2 × 270 = 13.98mm =

Faero _ f = ab f × 0.5 × r × V 2 × C L A 2

Value

Faero _ f

æ 220 ö = 0.45 × 0.5 × 1.225 × ç ÷ ×6 è 3 .6 ø = 6176.04 N Faero _ r = abr × 0.5 × r × V 2 × C L A 2

æ 220 ö = 0.55 × 0.5 × 1.225 × ç ÷ ×6 è 3.6 ø = 7548.54 N (2) So, in terms of tyre deflection, what we are looking at is shown in equation 3.

(3)

The reason we have multiplied the tyre spring rate by two is to account for the fact there are two tyres holding the car up. As can be seen with the cornering limit combined with the static ride heights, we are comfortably within specs of the current spring rates.

True limit The true limit condition is the end-of-straight condition, and if we re-run the numbers at 300km/h, things become most revealing, as equation 4 shows.

Faero _ f = ab f × 0.5 × r × V 2 × C L A 2

æ 300 ö = 0.45 × 0.5 × 1.225 × ç ÷ ×6 è 3.6 ø = 11484.4 N Faero _ r = abr × 0.5 × r × V 2 × C L A 2

æ 300 ö = 0.55 × 0.5 × 1.225 × ç ÷ ×6 è 3.6 ø = 14036.45 N (4) The tyre deflection now becomes as shown in equation 5.

td f =

Faero _ f 2 × k tf

11484.4 N 2 × 220 = 26.1mm Faero _ r td r = 2 × k tr =

14036.45 N 2 × 270 = 26mm =

(5)

Racecar Engineering • Formula 1 2022 39

SIMULATION What is immediately clear to see is that the end-of-straight condition is the limit condition, since the tyre deflection is almost half of the ride height value.

Fig 3: Applied front third spring bump rubber curve

Spring deflection The next challenge is to determine the front and rear spring rates. The first step in choosing this is to figure out the spring deflection you need. So, what we will choose is 10mm at the front and 20mm at the rear. This is being driven by two key considerations. Firstly, we want some wiggle room in terms of how we can adjust ride height (remember, the kerbs get a vote, too).

Also, if we refer back to Figure 2, we are going to be highly constrained in terms of what we can do with our front ride height.

To start working out the effective spring rates, we’ll use equation 6.

k f _ eff =

k r _ eff

Faero _ f

2 × ft _ damp 11484.4 N = 2 × 10 = 574.2 N / mm Faero _ r = 2 × rear _ damp 14036.45 N = 2 × 20 = 350.9 N / mm

mbf = 180kg (6)

The reason we can do such a simple calculation in this equation is the motion ratios front and rear are one. The big take away from equation 6 is that we don’t need to run a rear bump rubber (that said, we will run one anyway, just as a precaution), but we have a bit of work to do at the front.

The next port of call at the front is to figure out the total force we’ll need for the front bump rubber, which we will run on the third, or heave, spring. Doing the maths, the answer is produced by equation 7.

BR _ force fnt = Faero _ f - 2 × k f × ft _ damp = 11484.4 N - 2 × 270 × 10 = 6084.4 N (7) Given that we don’t want any huge discontinuities in the bump rubber, we will have this engage at a ground gap of 2mm.

The bump rubber curve is shown in Figure 3.

Now we have established the springing, we need to establish the base damper parameters. The rear is pretty straightforward, but I’m going to cheat a little bit and select a rear spring rate of 330N/mm. This brings the natural frequency at the rear in line with the front without the third spring.

40 Formula 1 2022 • Racecar Engineering

But what is the base spring rate we should select for the front? We choose a mid-point for the engagement of the third spring because this is what we’ll expect at the mid-corner conditions of the high-speed turns. Here we’ll see 5mm of bump rubber deflection. This is a spring rate of 500N/mm and so, split at the main spring where the damper is, this equates to an effective spring rate of 520N/mm (270 + 250N/mm).

The base damping rate at the front is therefore given by equation 8. And at the rear, it is as shown in equation 9.

520 ´ 10 3 180 = 53.74rad / s = 2 × w 0 × mb

w0 = C B _ fnt

= 19349.4 N / m / s

(8)

mbr = 220kg 330 ´ 10 3 220 = 38.72rad / s = 2 × w 0 × mb

w0 = C B _ rear

= 17041N / m / s

(9)

Now we have the base damping rates, we can start the work with the shaker rig toolbox. The base damper curve will be a bypass of 50mm/s. Note that is only an educated guess, but one based on a good deal of experience. That said, the base damping curve will be a damping ratio of one in the low speed and 0.5 in the high speed. And remember we are choosing a speed of 200km/h here, since this is the mid-corner condition.

The shaker rig toolbox results, in this case unredacted, are shown in Figure 4.

A very quick observation is that the baseline run was the spring rates we specified with the dampers as per the car model, not our specification that we just discussed.

From this run log, a couple of things pop out immediately. Firstly, don’t be shy about aggressive damping rates in the low speed, as that was imperative to keep the car’s platform controlled. Also note the drop in contact patch load variation when we went from run one to two, when the higher damping rates where applied.

Given our goal was to control this as a porpoising simulation, the final configuration chosen was that shown in run seven. The reason being the big drop in the cross pitch mode response, which should drastically reduce any porpoising behaviour.

To conclude this section of our discussion, let’s look at the final damper curves.

These are presented in Figures 5 and 6.

With the fronts in the low-speed bump we have kept very close to a damping ratio of one, forced upon us because of the high springing. In the high-speed bump, we have kept to a damping ratio of 0.5. No major surprises there.

You’ll note in rebound, the damping rates are less. This was driven by managing the contact patch load variation at the front.

The rear is very interesting though. In the high speed, the damping ratios are 0.5 in bump and 0.4 in rebound. Again, nothing particularly unusual about this. But note the high damping ratio of 1.17 in the low speed, which was to control the cross pitch mode.

Sometimes, this is just the way the cards fall to achieve the outcome you are after.

Lap time validation The final validation was to run this through lap time simulation, and the results are shown in Figure 7.

The baseline with the dampers set to that of the baseline ChassisSim model are coloured, while the new damper specifications, as per run seven, are in black.

Fig 4: Shaker rig run log

Fig 5: Final front damper curve

Fig 6: Final rear damper curve

The traces of note are the front and rear pitch (average of the left and right damper movement of the front and rear respectively) and the front and rear ride height. But note the reduction in oscillation of the pitches and ride heights. This gives you a much more stable platform to lean on.

While this is a considerable improvement, it’s still not a night and day situation.

Reason being the front tyre doesn’t have enough spring rate. So, while we did an effective job of improving the damper movement, it didn’t translate completely to the ride heights. This situation was also present at the rear, albeit slightly better because of the higher tyre spring rate.

Consequently, while there are gains to be had, if you are running on marshmallow tyres, your hands are very much tied.

Hopefully, this has shown, numerically, how to deal with porpoising and aeroinduced pitch oscillations on a highdownforce racecar. Using a combination of hand calculations and simulations we were able to make considerable progress toward negating the porpoising effect, but weren’t able to alleviate it entirely due to the low tyre spring rates. Some improvement is better than none though, right?

Fig 7: Comparison of the baseline model to the final damper specification

Racecar Engineering • Formula 1 2022 41

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