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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
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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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