From Le Mans to the road - Audi's diesel supercar
Audi took diesel power to the podium in the world’s greatest sports car race, the Le Mans 24 Hours, and now it’s doing the same for the road-going supercar.
This sensational concept coupe, running a 6.0-litre V12 diesel, was a show-stopper at this month’s Detroit Motor Show in the USA.
The coupe is based on the production Audi R8, and its motor develops 500 horsepower and 1000Nm of peak torque.
The V12 TDI engine is closely related to the engine in the Audi R10 double Le Mans winner.
Audi says the car will accelerate to 100kmh in 4.2 seconds and its top speed is well over 300kmh. Peak torque is developed at 1750rpm.
The engine has an 83.0mm bore and 91.4mm stroke and a displacement of 5934cc.
At 684mm the motor is only 166mm longer than Audi’s V8 TDI. It has two turbochargers mounted on the outside of the engine’s Vee, each supplying one bank of cylinders. Their variable turbine geometry means they respond slickly, even at low engine speeds. They generate up to 2.6 bar of boost pressure.
The six-speed manual transmission is very compact; combined with a small-diameter double-plate clutch, that means it can be installed low down.
The V12 TDU drives all four wheels through quattro permanent all-wheel drive; power is distributed variably between the front and rear wheels from a starting ratio of 40:60.
On the bodywork, a continuous aluminium spoiler lip connects the front and rear diffusers with side air baffles below the enlarged sills.
The cabin’s glass roof has two large transparent sections. A NACA duct in the middle of the roof is a functional detail normally found on racing cars. It accelerates the air drawn in for the two-cylinder banks.
The V12 engine is visible under a glass cover and white light-emitting diodes illuminate it at night.
Inside the cabin, an expansive arc runs around the steering wheel and instruments.
The three-spoke steering wheel is compact and ergonomic in shape. It has a flat lower edge – another race car touch. The steering wheel is covered in fine Valcona leather, with a diecast magnesium core.
The start/stop button for the engine and the Drive Select switch with the Dynamic/ Sport/Race settings are mounted on the steering wheel. The latter controls the engine and transmission electronics as well as the magnetic ride dampeners in each of the three different modes.
In Race mode, the instrument lighting changes from white to red. The navigation system shows a combined display with lap timer and navigation information for the racetrack being driven, or supplementary information such as centrifugal force and boost pressure can be called up.
Compared with the production version, the R8 V12 TDI concept’s interior has larger aluminium applications, especially around the centre console. The carbon fibre elements give the interior a sporty feel.
The body uses the Audi Space Frame technology, and is made from aluminium. The entire bodyshell weighs 210kg.
Audi aerodynamicists have styled the body shape to generate downforce, helping directional stability at high speed.
The add-on, automatically extended rear spoiler interacts with the air as it flows around the car. The extra downforce increases the efficiency of the air intake generated by the aerodynamic design of the underbody and diffusers. At low speeds, the rear spoiler returns to its initial position.
The suspension uses double wishbones at front and rear.
The show car has Audi magnetic ride which adapts the chassis characteristic to the profile of the road and the driver’s style within milliseconds.
The brake discs are made from carbon fibre-reinforced ceramic which is very hard and frictionally resistant.
Will Audi market a production version of the R8 V12 TDI show car? There’s no word yet, but it’s almost certainly on the cards.