|  The
monster engine boasts a specific output of 101bhp per litre. Perhaps the
best indication of where Porsche’s priorities lay with its new car
comes from the fact that its peak power is just 1bhp more than that claimed
by Mercedes for its upcoming SLR.
While Porsche possesses a great depth of knowledge in adapting four-wheel
drive to high performance, it was never considered for the Carrera GT.
“It’s a question of packaging,” says Achleitner. “Mating
four-wheel drive with a mid-engined layout requires too much space.”
Instead, power is channelled solely to the rear wheels via a race-grade
three-plate clutch and close-ratio six-speed manual gearbox that’s
mounted longitudinally behind the engine. A development of the magnesium-housed
unit used in the Le Mans racer, it lacks the sequential shift mechanism
likely to be demanded by customers - hence the traditional double-H gated
gear lever on the concept car.
Porsche is developing a shift mechanism similar to Ferrari’s much-lauded
F1 arrangement, in partnership with its Stuttgart neighbour, Bosch. However,
there are serious doubts about its reliability in handling the massive
torque loads produced by the new V10 engine.
Following
the current supercar trend, the Carrera GT is based around a lightweight
carbon fibre monocoque. Porsche says the computer-designed structure is
incredibly stiff and has been designed to incorporate a 90-litre rubber-lined
fuel tank between the cockpit and the engine to keep the weight concentrated
near the car’s centre point. The composite body, styled at Porsche’s
Californian design studio to revive memories of the 718RS Spyder from
the ’60s, is heavily influenced by the need to provide high levels
of downforce.
To this end, Porsche’s aerodynamicists have developed a retractable
rear wing which rises at speeds above 120kph. There’s also a flat
undertray and rear diffuser contributing to keeping the car planted to
the road. At 4560mm in length, 1920mm in width and 1190mm in height, the
Carrera GT is 80mm longer, 66mm narrower and 70mm higher than the F50.
The design of the concept is said to provide a solid glimpse of how the
production Carrera GT will appear. Porsche says it has learnt lessons
from its attempts to turn the elegant Boxster concept into production
reality, only to see its dimensions grow significantly in the end. “The
overall proportions, length of the overhangs and basic body form are already
locked in,” says Achleitner. The only major change will be the incorporation
of a roof structure. “We’re leaning towards a targa solution
with either a retractable window or roof panels.”
Porsche claims a preliminary kerb weight of 1250kg to give a phenomenal
power-to-weight ratio of 446bhp per tonne.
The suspension, like much of the Carrera GT’s mechanical package,
is race car-inspired. The front uses conventional double wishbones with
coil springs and an anti-roll bar. The rear is more exotic, with intricate
rose-jointed double wishbones and horizontally mounted coil-over-damper
units, pushrods and a sturdy anti-roll bar all bolted directly to the
gearbox housing, which acts as a fully stressed member.
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| Luxury
cabin gets multi-function wheel, digital display and aluminium
trim; in bench testing 558bhp monster engine has gone over 10,000rpm! |
|
|
January 2001 
