ANATOMY OF…MULSANNE TURBO & TURBO R

AN ANATOMY OF THE… THE BENTLEY MULSANNE TURBO AND TURBO R FAMILY

When the SZ range of models was born in 1980, it looked like the Bentley variants would linger on as badge-engineered versions of the better-selling Rolls-Royces. But dramatic changes were afoot.

WORDS: RICHARD GUNN PHOTOGRAPHY: KELSEY ARCHIVE/RICHARD GUNN

For Bentley enthusiasts, the SZ series of cars was where it all started to get good again. And then, it went beyond just merely good, and became simply superb. When Rolls-Royce took over Bentley in 1931, they were two very different marques. Rolls-Royce specialised in luxury leviathans for the very rich while Bentley was the builder of the ‘the fastest lorries the world’ as Ettore Bugatti put it. Blunt and brutal as Bentleys may have been - for they did lack the finesse of the cars from the company that swallowed W.O.’s old firm up - they had won Le Mans in 1924, 1927, 1928, 1929 and 1930. That gave them the sort of rakish, sporting appeal that Rolls-Royce could never muster.

However, when the first Rolls-Royceengineered Bentley appeared in 1933 - the so-called ‘silent sports car’ 3 ½ litre - it was a derivative of the Rolls-Royce 20/25. And that’s the way the vehicles wearing the Flying B mascot largely continued, with their chassis and engines shared with the machines crowned by the Spirit of Ecstasy. With the advent of the Standard Steel saloons, the distinction between the two marques was watered down even further. There were high points - such as the coachbuilt R-Type and S-Series Continentals - but with the advent of the monocoque Silver Spirit/T-Series models of 1965, Bentley became completely subsumed by Rolls-Royce. Aside from a few minor details, there was no difference between a Silver Shadow and a T-Series. It was even more extreme with the coachbuilt two-seater saloons and drophead coupés, for they weren’t even differentiated by separate names; the Corniche name was used whether a Rolls-Royce or Bentley. It was a badge-engineering fait accompli.

Predictably enough, with little to make Bentleys stand out, their sales plummeted. By the dawn of the 1980s, they made up just five per cent of Rolls-Royce Motors Ltd’s production. But a revival was just around the corner. In 1980, the business was purchased by engineering conglomerate Vickers PLC. It started looking closely at its new acquisition to try and maximise potential - and soon realised that Bentley was an under-utilised gem. Making its cars less like Rolls-Royce clones and instilling them with their own character and personality could well bring big dividends. The decision to bring back Bentley’s distinctiveness wasn’t a moment too soon: in 1981, 3014 of the newly-launched RollsRoyce Silver Spirit were produced. By contrast, there were just 151 examples of the equivalent Bentley Mulsanne.

The route Vickers chose to revitalise Bentley was to re-awaken its performance heritage. And the most cost-effective way to do that was to

introduce turbocharging. So, in March 1982, the company previewed probably the most exciting new Bentley since the 1950s at its traditional publicitygenerating launch venue of the Geneva Motor Show. The Mulsanne Turbo came as a complete surprise; Rolls-Royce had given no hints that such a machine was planned.

Compared to the £55,240 normallyaspirated Mulsanne with 198.5bhp, the £61,774 Mulsanne Turbo generated 298bhp - although Rolls-Royce traditionally didn’t like to reveal power outputs, new German rules had finally forced it to do so. This was a hefty and very usable power hike and meant a top speed of 135mph, as opposed to 119mph, was achievable, while 60mph from zero was reached a full three seconds faster, in just seven seconds. The 0-100mph time was even more of a remarkable contrast; the Mulsanne’s sprint to the ton took 30.8 seconds, the Turbo 17.9 seconds.

LESS POLISHED ON CORNERS

Aside from the bulky Garrett AiResearch TO4 turbocharger bolted onto the traditional 6750cc V8 (see Back to Blower Bentleys overleaf), which necessitated the repositioning of the power-steering pump and its belt, there were no other mechanical tweaks save for altering the settings on the GM THM400 automatic transmission, raising the final drive ratio and fitting thicker final-drive output shafts. The suspension was left untouched - which meant that, as fast as the car was in a straight line, it was somewhat less polished on corners. The Mulsanne Turbo’s appearance was also very subtle. The 1980s was a time when turbocharged vehicles liked to scream their status with lairy graphics and colour schemes, but that wasn’t at all the sort of thing Bentley deemed appropriate. So, instead, the radiator shell was painted to match the body rather than chromed, and there was a small ‘Turbo’ badge on the lefthand side of the bootlid, matching the style and positioning of its ‘Mulsanne’ »

Rolls -Royce Silver Spirit

Non-turbo Mulsanne hardly differs at all

“It was all very discreet, almost as if the company was just dipping a toe in the water to see if the turbocharged Bentley had any market potential”

counterpart at the other end. It was all very discreet, almost as if the company was just dipping a toe in the water to see if the turbocharged Bentley had any market potential.

It did. Crewe’s initial estimates were that it could sell 100 Mulsanne Turbos every year. Yet after the initial 35 of 1982, 202 were built during 1983 and 209 the year after that. And this was without any sales in the USA, as the turbocharged engine couldn’t yet meet Federal emissions regulations. One UK buyer, albeit fictional, was James Bond. In the 1984 John Gardner novel Role of Honour, he returned to his Fleming-authored Bentley roots when he replaced his earlier Saab 900 Turbo with a British Racing Green Mulsanne Turbo. Unlike most 007 cars, it was light on gadgetry, Rolls-Royce requesting that the only extra gimmick it carried should be a telephone. »

Mulsanne Turbo's subtle difference: body-coloured grille surround All were still hand-finished products in the 1980s & '90s

BACK TO BLOWER BENTLEYS

It was in 1973 that thoughts within Rolls-Royce first turned to turbocharging, spurred on by emerging trends within the automotive world. Of course, Bentley already had serious history with supercharging, from its 1920s’ 4½-litre ‘Blowers’, but turbocharging was another matter. Although American marques had dabbled with turbocharging in the 1960s, had Crewe gone down the route in the mid-1970s, it would have been ahead of the European game. BMW’s 2002 Turbo didn’t arrive until late ’73, Porsche didn’t fit its 911 with a turbocharger until 1975 and Saab only joined the Germans in 1978. However, although Rolls-Royce’s managing director David Plastow was keen on the idea, there was considerable resistance elsewhere within the company, despite it already having some turbocharging experience courtesy of its industrial diesel engines. Nevertheless, a rather worn-out Silver Shadow was sent off to tuning firm Broadspeed in Birmingham. Half a year and £7000 later, the car returned. What RollsRoyce got back was a turbocharged car that was very unrefined in some respects - tickover was reported as being a particularly problematic - but also very fast. Development continued over the next few years, but eventually the turbocharged Shadow was scrapped, at some point post-1977. However, when the Mulsanne Turbo appeared in 1982, it employed much the same system as Broadspeed had originally come up with, using a sole Garrett AiResearch TO4 turbocharger driven by the right-hand side exhaust manifold providing considerable extra urge, even with boost limited to just 7psi. As fuel injection was still a few years away, the carburettor choice was between twin SUs or a single Solex 4A1 (as employed on the Corniche and Camargue). Rolls-Royce and Broadspeed opted for the Solex because it could be packaged more easily in a sealed chamber to receive the pressurised feed from the turbo.

“...James Bond who, in the 1984 John Gardner novel Role of Honour, returned to his Fleming Bentley roots when he replaced his earlier Saab 900 Turbo with a British Racing Green Mulsanne Turbo”

Quad headlamps distinguished the Turbo R from mid-'88, with non-Turbo Bentleys following suit However, Gardner also sneaked in a hidden weapons compartment too. The Bentley continued to be Bond’s personal car in the following book Nobody Lives Forever.

In addition to the standard saloon, there was also the little-known long wheelbase Mulsanne Turbo L, with an extra four inches of legroom. However, just 18 of these were built by the time the Mulsanne Turbo was superseded in March 1985. By contrast, there had been 498 of the standard wheelbase saloons.

The replacement for the Mulsanne Turbo was the Turbo R. The ‘R’ stood for ‘Roadholding’ and was an attempt to address the deficiencies of the turbocharged Bentleys through the twisty stuff (see Keeping to the Road, right). The Rolls-Royce Silver Spirit

KEEPING TO THE ROAD

How do you make something as big and, well, soft, as a Silver Spirit/ Mulsanne capable of tackling corners as well as straights? That was the question facing RollsRoyce engineers in the mid-1980s when they sought to address the handling quirks of the Mulsanne Turbo. Fitting a turbocharger to the big, bulky Bentley had established there was a desire for a performance model again; now was the time to give it more substance. Fortunately, by the mid-1980s, there was a new development team in place, with Mike Dunn having taken over from John Hollings as engineering director in 1983. He was much less wed to the established Rolls-Royce philosophy of making everything as comfortable as possible, no matter how slushy and soporific it made the general feel. At first, his engineers suggested changes that firmed up the car by 10 per cent, but Dunn pressed for 50 per cent. He got his wish, with the suspension tweaks to the new Bentley Turbo R of 1985 including stiffening the front anti-roll bar by 100 per cent and making the rear one 60 per cent stiffer. There were also stiffer dampers and the rack-and-pinion got a lower-ratio pinion gear to promote more positive

on which the Bentleys were based were intended to waft around with very soft, compliant suspension. The Turbo R, with its substantially modified and harder suspension, improved matters considerably, even if the sheer weight and size of the Bentley limited how much it could be transformed into a true sports machine.

The Turbo R’s price was £68,831 at its March 1985 debut. Aside from the alloy wheels, there wasn’t too much to distinguish it from its predecessor, with the grille painted to match the body colour being the only other thing that really marked the model out from the Rolls-Royce Silver Spirit. Nevertheless, it continued to fuel the Bentley renaissance; with sales rising to around 300 during 1986, Flying B cars now represented 40 per cent of total Rolls-Royce production, an impressive improvement from five per cent just half a decade earlier. And this was still without the model being exported across the Atlantic to America.

In 1986, steps were taken to make that happen. The Turbo R received more emissions-friendly fuel injection in the form of the well-proven Bosch KE-Jetronic system, with digital ignition. This raised power to 330bhp and gave a top velocity of 143mph. This was proved - give or take a couple of mph - at the Millbrook proving ground in September of that year when 140.96mph was achieved by a Turbo R, setting 16 new speed records in the process. One of them was the national one-hour speed record, with the Bentley stealing the crown from the Lamborghini Countach. It was a very high profile and patriotic demonstration of just how potent the Turbo R truly was. Anti-lock brakes, slimmer sports seats and higher rear axle ratio were also fresh for ‘86 but, naturally, received rather less attention than the engine upgrades.

THREE-YEAR WAIT

Despite the adoption of fuel injection, the Turbo R didn’t reach America until 1989, by which point Bentleys had moved even further away from their Rolls-Royce counterparts with the introduction of a new four-headlamp nose and more prominent front spoiler. When the R hit the USA, sales took off. 319 went across the pond that year, as part of 1046 examples constructed in total. The waiting list between ordering one and receiving it now stretched to three years.

For the 1990 model year, electronic adaptive suspension was installed; the harder a car was driven, the firmer its damping automatically became. It was a boon for those who liked to drive their Bentleys on the limit but also appreciated comfort when cruising. An air-to-air intercooler also made »

steering with slightly less power assistance. Alloy wheels were also adopted - something new for RollsRoyce - while a leaf was taken from Aston Martin’s book with the fitment of Pirelli P7 265/55 VR 15-inch tyres. And if they were good enough to keep Aston Martin V8s from spinning off into the scenery… The result was a model that gave a harder ride than any other post-war Bentley, and while not everybody at RollsRoyce was impressed by the loss of the usual cushioning, customers certainly appreciated a car they could hustle through bends far more effectively - and safely - than before.

an appearance. The following year - which was when Bentleys achieved sales parity with Rolls-Royces - the Turbo R received the four-speed GM 4L80-E automatic transmission.

By the mid-1990s, Bentley had discovered the joy of special editions, as a means of upping the appeal of the Turbo cars in the wake of the newer Continentals of 1991 onwards. In autumn 1994, the Turbo S was announced. This featured a tuned Continental engine of 408bhp, plus 17-inch wheels. It cost £147,500 and only 60 were constructed but, with a top speed of 155mph, it was the fastest Bentley ever.

The ‘mainstream’ Turbos went up to 385bhp for 1996, thanks to a thorough reworking by engine specialist Cosworth (one of Vickers’ other businesses) which applied its Formula 1 expertise and also dropped in a Zytec EMS 3 engine management system as part of its improvements. 17-inch wheels also became part of the standard spec. These cars became known as ‘New’ Turbo Rs because of the scope of their modifications, which also included other cosmetic changes. Bentley wasn’t finished for the year though. In addition to the Brooklands (Bentley’s normallyaspirated entry level ticket from late 1992 onwards) gaining a light pressure turbocharger during the same year, there was another limited edition, the Turbo R Sports, with the improved brakes and alloy wheels of the Continental T as well as a sat-nav system and carbon-fibre rather than walnut panelling inside.

Traction control was all-new for 1997, but by now the square-rigged SZ style was approaching its sell-by date. That the writing was on the wall for the Turbos was highlighted by the shorter wheelbase R being discontinued, leaving only the four-inch longer wheelbase RL in production - albeit renamed as the Turbo R. There was a late blaze of glory though, with the Turbo RT launched in July of that year. This was a £148,990 RL powered by the 400bhp Continental T V8 and sporting a mesh grille, colour-coded bumpers and five-spoke alloys. Manufacture was limited to 252 plus 56 editions more luxuriously-trimmed by Mulliner, the old coachbuilder’s name now used for the company’s personal commissioning department. Thanks to an uprated turbocharger »

In late-model Turbo Rs, the engine began to disappear under plastic covers. Easier to clean!

PRODUCTION FIGURES

Continental R (1991-2002) 1292 Bentley Mulsanne Turbo (1982-1985) 498 Bentley Mulsanne Turbo L (1982-1985) 18 Bentley ‘Original’ Turbo R (1985-1995) 4653 Bentley ‘Original’ Turbo RL (1985-1995) 1211 Bentley Turbo S (1994) 60 Bentley ‘New’ Turbo R (1995-1996) 543 Bentley ‘New’ Turbo RL (includes LWB Rs from 1996 on, 1995-1997) 823 Bentley Turbo R Sport (1996) 20 Bentley Turbo RT (1997) 252 Bentley Turbo RT Olympian (1997) 4 Bentley Turbo RT Mulliner SWB (1997) 7 Bentley Turbo RT Mulliner LWB (1997) 49 Bentley Brooklands R (1997) 79 Bentley Brooklands R Mulliner (1997) 100

1975 HANWELLS OF LONDON 2022

2014/14 Bentley GTC Speed W12. Finished in Beluga with 21 inch Speed alloys. The interior hide is in Linen leather, with Beluga stitching and Beluga carpets. Fitted with ventilated massage front seats, neck warmer and park camera. Only 34,000 miles with FSH. Immaculate condition throughout ........................................ Only£68,950 2012/62 Bentley Flying Spur Mulliner. Finished in unmarked Hallmark Silver with 20 inch alloys and electric sunroof. Linen leather interior with contrast stitching and embossed Flying B’s, with Beluga secondary hide and rear park camera. Only 47,000 miles with FSH. Known to us for 6 last years, immaculate ........£41,950

2006/55 Bentley Arnage T Mulliner Level II. Finished in beautiful Moonbeam Silver with Beluga interior and contrast stitching in Cornsilk, with Walnut veneers. Finally, to complete the luxury there are picnic tables in the rear. Only 55,000 miles with FSH. Immaculate condition and amazing value at ...................................£36,950 2004/04 Bentley Arnage T Mulliner. Finished in Beluga with 19 inch split rim alloys. Beluga interior with turned alloy dash and door cappings. Only 40,000 miles with full history, previously supplied by us 6 years ago. Four new tyres just fitted, immaculate condition throughout and outstanding value........£33,650

2003/03 Bentley Arnage T Mulliner. Finished in Moroccan Blue with Silverstone interior, with embossed flying B’s in French Navy and DVD screens in the rear of the front headrests. We have known this car for the last 8 years, only 68,000 miles with Full Service History, immaculate condition throughout.........£27,950 1997 P Bentley Brooklands Turbo. Finished in Silver Pearl with Turbo RT alloys, with Silverstone interior piped in French Navy and French Navy carpets with Silverstone piping and comfort seating design. Known to us for 9 years and maintained regardless of cost. Stunning and outstanding value at .......£19,750

1997 Model P Bentley Continental R. Finished in Racing Green with a matrix grille and limited edition 17 inch alloys. With London Tan interior, this very rare car has only covered 43,000 miles with a Full Service History and 19 service stamps. Increasing in value and would make a very good investment ..............£52,950 1977 R Rolls Royce Corniche FHC 2 dr Coupe. Finished in Sand with a Walnut vinyl roof and white wall tyres. Cream interior with Cream carpets, with Walnut piping and Walnut veneers, all in perfect condition. Only 48,000 miles, known to ourselves for last 7 years. Lots of history, a superb investment.............£69,950

1937 Bentley 4¼ Park Ward Four Door Sports Saloon Well finished in Dark Green with excellent Buff leather. Very well cared for by one owner of almost 30 years & much spent inc. new head & o/drive, meticulous history file; Just arrived. Seven other interesting Derbys: open/closed, 3½, 4¼, O/Drive.

1928 20hp Flewitt D-Back Six Light Limousine Correct and handsome with much recent major engine work & full re-wire. Runs & drives very nicely, could be used as is but would benefit from some cosmetic improvement; £27,500 Great choice of 16 pre-war Rolls-Royce cars, open & closed.

1970 Rolls Royce Silver Shadow Series I. Finished in completely unmarked Seychelles Blue with a single Shell Grey coachline. The Shell Grey interior is in almost new condition. The French Navy carpets with Shell Grey piping are as new. Very comprehensive history. Immaculate throughout, an investment at .........Only £25,950 1964 Rolls Royce Silver Cloud III. Finished in Astral Blue over Shell Grey with the most amazing bodywork. Having a Silverstone interior which looks in the same condition as a 3 year old car and fitted with air conditioning. Maintained regardless of cost, keeping the car in superb condition. An investment at ..................£82,950

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1957 Bentley S1 Four Door Sports Saloon Beautifully correct, structurally excellent & a pleasure to drive Lovely soft original tan leather – in fact the whole car is a delight throughout, plenty of history, well substantiated 67k miles: £55,000 Superb S1 Flying Spur, 2 Bentley R-Types, ’53 S/Dawn Automatic Visit us at the RREC Annual Rally at Burghley House. Visit our eBay Real Car Co Parts shop –follow link on our website.

compressor, these also had 420bhp in addition to their more rounded bumpers, additional venting and flared wings. One unusual option was the provision of a speedometer for passengers in the rear; ideal for backseat drivers. The London dealership of Jack Barclay also commissioned four RT Olympians, based on the Mulliner but packed with as many special features as possible.

Away from the RT, the Brooklands also got a final boost, changing name to become the Brooklands R and gaining the suspension settings and alloy wheels of the RL. The last 100 were christened the Brooklands R Mulliner with, as the name suggested, even greater levels of refinement courtesy of Mulliner. The final Bentley SZ models were completed in December 1997, after which attention switched to the new Arnage generation.

Those first turbocharged cars dramatically transformed Bentley’s fortunes though, helping the marque emerge from Rolls-Royce’s shadow and assert its own individuality and performance credentials. The renowned American magazine, Motor Trend, highlighted the Turbo R as ‘the first Bentley in decades deserving of the famous name’, a statement with which it’s easy to concur. Without the line that began with the Mulsanne Turbo in 1982, Bentley might well have disappeared during the decade, as its sales diminished further. Instead, by the end of it, the brand was stronger and more desirable than ever before, and a lot of the success of the company today is due to the sporty foundations re-established during the 1980s. ■

THE

VIEW

John Tupper, managing director of IntroCar, says:

The introduction of the Mulsanne Turbo was intended to be a direct reference to Bentley's sporting past, and to differentiate Bentley's offering from that of Rolls-Royce (thus appealing to a slightly different market). Whether this was successful is by no means clear, but it marked the beginning of a change in customer buying habits that would eventually result in customers eschewing the RollsRoyce marque in favour of Bentley - at least in terms of sales volumes. This continues to the present day when sales of Bentley motorcars still exceed that of Rolls-Royce.

The Mulsanne Turbo, and the early carburettor Turbo R, was equipped with fierce acceleration for a car of its size, matched by an equally ravenous fuel consumption. This was courtesy of the Solex 4A1 carburettor, which works fantastically well - when it works - and when visits to the petrol station are a happy experience for the owner. These days I suggest that the Mulsanne Turbo (or carburettor Turbo R) is best purchased by those who really want to own a piece of motoring history - for that it is. Most in the know will probably concur that early versions are not for the faint hearted. Apart from drinking petrol, the carburettor has a limited lifespan, and engine heat often warps it, usually consigning it to the dustbin. Replacements are more-or-less impossible to find, and a non-original replacement, fitted by technicians well-versed in retro-fitting fuel systems is the most practical solution. By the time the Turbo R had been equipped with Bosch fuel injection (far more reliable, fuel efficient and serviceable) you begin to have a more robust ownership proposition. The Turbo R continued through various iterations to 1997. Indeed, if you purchase one later than 1996, with its Zytek engine management system, then you are purchasing - in the writer's view - the finest of the four-door Bentleys of the 1980s and 90s. Enormously comfortable, powerful and driveable, they can be driven daily without a second thought.