bentley la mans winner

The victorious Bentley Speed 8 of Kristensen/Capello/Smith ahead of the second placegetting car driven by Herbert/ Blundell/David Brabham, Le Mans 2003. (unattributed)

Wonderful outcomes of automotive industry mergers and takeovers of the last 20 years or so has been the resurgence of the ‘Great British Grand Marques’; Rolls Royce, Jaguar, Aston Martin and Bentley. Ford were very good for Aston’s and Jaguar, (noting the subsequent changes in ownership of both companies) BMW for Rolls and Volkswagen Group’s Bentley investment in 1998 put the brand back where it deserved to be.

bentley continental gt

Successful merchant bankers conveyance of choice; Bentley Continental GT. (unattributed)

Apart from the product driven strategy starting with the Continental GT Coupe in 2003, an important part of relaunching and repositioning Bentley as a brand was victory at Le Mans. The company achieved this 5 times under WO Bentley’s leadership/ Woolf Barnato’s ownership between 1923 and 1930.

wo bentley

The 1924 Le Mans winning Bentley 3 litre. WO Bentley in the middle with drivers Frank Clement, left and John Duff. 4 cylinder fixed head, the block and head cast as one, SOHC, 4 valve, twin plugs with ‘pent roof’ combustion chambers, 2996cc, very long stroke engine. 4 speed gearbox, 4 wheel brakes from 1924. Circa 1800Kg. (unattributed)

le mans 1925

Le Mans pit scene in 1925 featuring the #10 Herbert Kensington Moir/ Dudley Benjafield and #9 John Duff/ Frank Clement Bentley 3 Litres. Not a happy year for the marque, both cars DNF, the race won by a Lorraine Dietrich B3-6. (unattributed)

bentley 4.5

Gendarmes aboard the victorious Rubin/Barnato (right) Bentley 4.5 litre, Le Mans 1928. Chassis ‘ST3001’, was a ‘Long Standard’ type with a 101 inch wheelbase. The car was a prototype, the 3 litre engine described above enlarged to 4398cc, it used a stronger crank, rods and pistons. Power was 100-110bhp, 20 more than the 3 litre, the car good for 100mph @ 3500rpm. Suspension still by quarter elliptics front and rear. (unattributed)

image

Bentley boys @ Le Mans in 1928 L>R Rubin, Barnato, Birkin aboard the winning 4.5 litre, Clement and Benjafield (Popperfoto)

VW Group embarked on a 3 year program to win Le Mans with a Bentley ‘off the back’ of the Audi R8’s Le Mans success three years on the trot from 2000-2002. In 2003 there was a transition of their efforts from the all conquering R8’s, no works Audi’s were entered that year, to the Bentley Speed 8, that years contender.

The Audi race subsidiary RTN (Race Technology Norfolk) built an entirely new car, still a closed prototype or GTP class car designed by Peter Elleray who also concepted the ‘EXP Speed 8’ used in 2001 and 2002. Best placed of these cars was 3rd and 4th respectively, the all-conquering Audi R8’s in front of them in both years.

Elleray graduated from Durham University with a Bachelor of Science in Applied Maths, he then did some analysis work with Tyrrell in 1982 on their ground effect tunnels before getting a job with Arrows F1 having assisted several Formula Ford teams. He later worked as a design and race engineer running Gerhard Berger’s car in 1985. He was appointed Chief Designer of the Bentley program after Le Mans 1999.

cutaway

Bentley Speed 8 cutaway drawing. (Peter Hutton)

In an interesting interview of depth with mulsannes.com Elleray outlined the secrets of Bentley’s 2003 Le Mans success ‘I start with the aero side and then try to fit a workable structure and suspension systems into that…One of the very good pieces of advice I was given a number of years ago is to design the car you want and then make it fit the regulations!’

exp speed 8

The 2001 Bentley EXP Speed 8, Le Mans 2001. This car finished 3rd driven by Andy Wallace/Butch Leitzinger/Eric Van Der Poele, the sister car DNF. In 1st and 2nd positions were Audi R8’s. Car powered by 3.6 litre twin-turbo V8 in 2001, 4 litres in 2002 and 2003. Prototype built in 2000 did not race. (netcarshow.com)

Elleray conceded the Bentley benefited from the race winning Audi R8C ‘The prototype Bentley 00 car which never raced, did benefit from R8C experience, but only in as much as showing us what not to do!…I did reintroduce a number of suspension elements on the ’03 car when nobody was looking. There was not a lot of carryover of design staff from the R8C and subsequent Bentley projects…’

audi r8

Tom Kristensen in the Audi R8 he shared with Frank Biela and Emanuelle Pirro to win Audi’s first Le Mans in 2000. Audi’s 1-3rd. Carbon fibre and aluminium honeycombe chassis, 3.6 litre V8 twin-turbo engine, circa 610bhp in 2000, Ricardo 6 speed sequential ‘box, suspension; wishbones and pushrods actuating horizontally mounted shocks, front and rear. Designed by Michael Pfadenhauer (aero) and Ulrich Baretzky (engine). (unattributed)

bentley front

2003 Bentley Speed 8 front detail. Inlet for radiators in conventional midships position. The air flows past the suspension and a ‘faux duct’ whose aim is to reduce lift generated by the air as it goes over the bodywork. (Autosport/ Bob Chapman)

The GTP closed rather than open-car design was chosen because ‘the visual presence of the GTP may have been as important as anything else…If you look back through the history of prototype racing the closed cars have always been the most charismatic, and, in as much as the racing was part of their marketing strategy them I’m sure this was a factor’.

There was little mechanical carryover from ’02 to ’03 apart from the engine and internal layout of the gearbox. Some of the torsion bar system was carried over at the front but the rear was all new. The layout of the cooling system was the same, as were the front diffuser section and the Kayaba electric power steering.

front suspension

Front suspension by wishbones top and bottom, telescopic dampers, torsion bars and adjustable roll bar. Carbon fibre tub clear as is the diffuser strake leading edge. The structure housing the brake inlet duct also forms the trailing edge of the diffuser. (Autosport/Bob Chapman text Michael Fuller)

‘In contrast to that all of the key performance related parameters changed. Weight distribution, aero concept and map, suspension geometry, all changed significantly...all done due to the knowledge that only a win would be acceptable. If you know you are going to be in serious trouble if you finish second then it probably encourages you to take a few chances…’ Elleray said.

The good results started with the aerodynamics ‘The car had a good level of downforce over a wide range of ride-heights and pitch angles which meant that it could run softer than the ’02 car…that (may) have assisted Michelin in a way we hadn’t assisted Dunlop (in prior years) but the race showed that we were able to look after the tyres and still be quick…the changed suspension geometry played a part ‘

‘The other thing was that we ended up with a very drivable balanced car, although that came about during the test program rather than off the drawing board…that had been a case of trying different roll and heave stiffness, seven post rig testing and also playing with weight distribution a bit. The aero map being stable over a wide range was also a function and then Michelin responded with the right tyres for the car and suddenly we were right there…’

Bentley-AM3

3 D model of the Bentley Speed 8 carbon fibre and aluminium monocoque. Carbon roll hoop assemblies integrated with the roof structure. (Alastair Macqueen)

All of the Bentley monocoques have been in the 70 Kg region which is to a large extent due to the FIA tests the chassis has to pass before it can race. The nose box tests the car passed easily but the roll hoop test, designed for open cars was more difficult.

After Eric Van Der Poele’s big accident at Paul Ricard in 2002, even though he was unhurt, Elleray decided to make the car more like an open one with a monocoque coming up in one piece to the drivers shoulders with a separate hoop of carbon on top of that.

A 360 degree hoop was inserted at the dashboard and a roof was glued on top of the two hoops to join them together. Elleray ‘figured this would be able to withstand repeated impacts better’.

bentley engine

Engine 4 litre, DOHC, 4 valve, twin-turbo 90 degree V8. Circa 615bhp and 590 lb ft of torque @7500 rpm. Boost pressure limited to 1.87 bar by ACO in 2003. Gearbox; Bentley case with Xtrac 6 speed sequential internals. Rear suspension upper and lower wishbones with telescopic dampers and torsion bars. Adjustable roll bar. (autosport/Bob Chapman)

The development of the 4 litre twin-turbo V8 to run with air inlet restrictions, imposed by the authorities to reduce power and speed in all 4 Le Mans categories in 2003 was also an important success factor. The 3 privately entered Audi R8’s which were Bentley’s main opposition had little development of their 3.6 litre engines to combat the regulation change; in short VW Group wanted Bentley to win in 2003.

The open Audi’s had the advantage of being easier to access during the race and had wider rear tyres and therefore better life and fuel economy whereas the Bentleys were superior in top speed but needed to change tyres and refuel more often.

bentley 8

The Herbert/Blundell/David Brabham 2nd place Speed 8. Le Mans 2003. (unattributed)

In terms of Le Mans itself, Audi’s winning factory drivers over the previous 3 years were farmed out; Tom Kristensen elected to lead the Bentley Team and asked that Rinaldo Capello join him, Guy Smith was the third driver in the #7 Bentley. Le Mans winning team, Joest Racing provided ‘in field’ support to Team Bentley.

Emmanuelle Pirro joined the Champion Racing Team driving its R8 and Frank Biela lead the British Audi Team also R8 mounted. Biela had the pace but made an error and overshot the pit entry, the extra lap ran the car out of fuel.

profile

Nice shot which shows the profile of the 2003 Speed 8, the winning car and complex aero of the ‘modern’, its 12 years ago now, Sports Prototype. Carbon fibre brakes aglow. Brakes; AP Racing 14.8 inch front / 14 inch rear carbon fibre discs with 6 piston calipers. (unattributed)

The #7 Bentley lead almost every lap of the race, 377 in total and didn’t lose a lap in damage or punctures. Guy Smith was given the honor of piloting the Speed 8 across the line to mark an emotional sixth win for Bentley after the elapse of over 70 years.

Johnny Herbert, Mark Blundell and David Brabham were 2nd in the #8 Bentley, 2 laps behind the winners. They lost time with an unscheduled stop on the Saturday afternoon when the drivers headrest broke free in the cockpit and a few minutes on Sunday when the battery was changed twice.

With Le Mans won, it was ‘marketing mission accomplished’ for the VW Group, the Bentley prototype racing program was at and end. Audi have now won the race 13 times since their initial victory in 2000 with a variety of interesting cars; petrol, diesel and now hybrid powered.

paris

Post Le Mans victory parade in Paris. The winning Speed 8 between the 2 crews aboard ‘Blower’ Bentleys. Nice juxtaposition of Le Mans technological advancement over 70 years! And rich Bentley brand heritage. (unattributed)

Etcetera…

Bentley-BC24 sebring

Speed 8 at Sebring 2003. Interesting shot shows the aero treatment; wheel well air outlets on top of guard and at the side, and inlet for carbon brakes. Wheels are O.Z. forged magnesium, 12.25/13 inches wide front/rear and 18 inches in diameter. Tyres Michelin in 2003. The cars started from the back of the Sebring grid after a technical infraction caused by exhaust heat distorting the cars flat floor, as a result the rear diffuser was too high, its height measured from the floor. A plywood filler piece solved the problem. The Speed 8’s finished 3rd and 4th at Sebring, Audi R8’s in 1st and 2nd. Valuable testing gained. (Autosport/Bob Chapman)

aero

Rear deck detail and aluminium strakes added to duct more air to the brakes after cooling concerns at Sebring. You can also see the very neat tail light at the trailing edge of the cockpit ‘bobble’. Between the 2 small ducts. (Autosport/Bob Chapman)

Bentley-BC25 sebring with fazz behind

Herbert/Brabham/Blundell, 3rd place, Bentley Speed 8, Sebring 2003. Car behind is a Chev Corvette C5-R. (Autosport/Bob Chapman)

photo (10)

Bentley Team at Le Mans 2003. Plus a factory at Norfolk to build the cars. Even with the technology transfer from the ‘family’ Audi R8 program, victory in 3 years was a considerable achievement, many have spent more and not won at all…(unattributed)

Bibliography and Credits…

Automobile Year 51: Andrew Cottons Sportscar Review, mulsannescorner.com, Autosport, Bob Chapman, Michael Fuller, Alastair MacQueen, netcarshow.com, Popperfoto

Tailpiece…

Bentley-BC26 sebring from behinsd

Bentley Speed 8, Sebring 2003. Hopefully a return to outright Le Mans contention again soon? (Autosport/Bob Chapman)

Finito…

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