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The 2003 Bentley Speed 8 Technical Story

London, 4th February 2003... It is no exaggeration to describe the Bentley Speed 8 Le Mans GT prototype that will race at both Sebring and Le Mans as a new car. Though the previous two generations of Speed 8 performed spectacularly well, returning Bentley to the Le Mans podium in 2003, it was felt that for the final year of the three-year programme, a fresh approach was required.

Clearly the car still features enclosed bodywork meaning it remains in a class of its own and the engine retains its basic architecture, 4-litre capacity, direct fuel injection and twin turbochargers. In all other significant respects it is a new design from the ground up.

The concept driving the design was to ensure much better exploitation of the airflow over the body and particularly to the rear wing. To achieve this, the external cockpit area has been much reduced - though the car is actually more spacious inside - making a smaller hole in the air and allowing the car to use a much smaller, more aerodynamic engine cover.

In addition, the air-intake that had sat on top of the car in previous generation Speed 8s has been deleted in favour of 'snorkel'-type intakes on the sides of the car. This not only further increases the efficiency of the air-flow over the car, it also lowers the height of the car, lending it a much more sleek, aggressive appearance. Early testing results have indicated that not only does the 2003 Speed 8 have a more favourable downforce to drag ratio than its predecessor, it also offers much more consistent aerodynamic performance in all conditions making the car both quicker and easier to drive.

Underneath the new skin the 4-litre engine has been re-engineered around the new regulations for 2003 that dictated a ten per cent reduction in engine restrictor size across all classes competing at Le Mans. It has been necessary to redesign many internal engine components as well evolve a new electronics strategy for the engine to minimise the shortfall in power that the new regulations will bring to all competing teams.

The suspension has been entirely redesigned as well, partly to improve further its behaviour, but also so it can be adapted to suit its new Michelin tyres. All the geometry has been changed even the mounting points of the rear suspension on the gearbox.

This alone has necessitated a new gearbox casing for the Speed 8. As in previous generations of Speed 8, the internals are supplied by Xtrac and continue to operate with their customary reliability.

The testing programme has proceeded apace. The autumn was spent doing extensive tyre testing, benchmarking the new Michelin tyres and determining how best to exploit their performance. These tests were conducted with a 2002-specification EXP Speed 8. Early in the New Year, the first of the 2003 Speed 8s was shaken down successfully at Snetterton before heading off to the circuits of Europe for an extensive test programme prior to Sebring.

Bentley Team Director John Wickham commented: 'The new car clearly has great potential, the drivers are very happy with the progress we are making, particularly its aerodynamic balance. As with all Bentleys we have run in the last two seasons, reliability appears to have been 'designed in'. It's early days but so far we have had no reliability issues with the car whatsoever.'

Andy Pope, speaking for Michelin, said: 'The first few weeks of our association with Bentley have been extremely encouraging. We have not recently made tyres in the sizes dictated by the LM GTP class, but we appear to have found our feet very quickly and are able to supply Team Bentley with tyres that are quick, consistent and durable.'

Team Bentley's latest Le Mans racer versus the first ever Bentley Le Mans car

  2003 Speed 8 1923 3-litre
Chassis Carbon-fibre monocoque Pressed steel, ladder frame
Body Stressed carbon-fibre by Race Technology Norfolk Aluminium and canvas by Vanden Plas
Engine 90 degree V8, four valves per cylinder, twin overhead camshafts, twin turbochargers In line, 4 cylinders, four valves per cylinder, single overhead camshaft, normally aspirated
Ignition Bosch 2.8 engine management Twin ML magnetos
Fuel delivery Bosch 2.8 engine management Zenith RA carburettors
Lubrication Dry sump Wet sump
Capacity 4000cc 2996cc
Power output In excess of 600bhp 86bhp
Gearbox Bentley casing with Xtrac 6-speed sequential internals, Megaline pneumatic actuation Bentley 'A'-type 4-speed, non-syncromesh
Clutch AP Racing multi-plate Cone-type
Suspension Double unequal length wishbones all round, torsion bar springs (front and rear), telescopic dampers Beam axle front, semi-floating live rear axle, semi-elliptic springs all round, Hartford lever arm dampers
Steering Kayaba EPS Power assisted rack and pinion Unassisted worm and wheel
Brakes Front: 14.8in ventilated discs, six piston AP Racing callipers.
Rear: 14.0in ventilated discs, six piston AP Racing callipers
Front: none
Rear: 15.7in cast iron drums, Halo linings
Wheels OZ forged magnesium 18in Rudge-Whitworth wire, 21in
Tyres Michelin slicks and wets Dunlop treaded
Wheelbase 2735mm 2984mm
Length 4645mm 4876mm
Weight 900kg 990kg (without body)
Top speed In excess of 215mph 95mph

 



 
 
 
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