[charly]

The Audi R10 TDI powered prototype hit the track today for the first time in the US as Sebring testing commenced for the 2006 ALMS season. This car is unbelievable. It sounds like nothing I have ever seen or heard before. Its QUIET, really really quiet. It makes no more than a weird hum and whistle as it heads down the track. It sounds almost like a regular stock Viper V10 or something like that would sound going down the highway.

The V12 TDI used in the R10 is the first Audi diesel engine with an aluminium crank case. The cylinder-bank angle is 90 degrees. The V12 TDI has, like Audi production car engines, four valves per cylinder and twin overhead camshafts. The fuel induction is made by a modern “Common Rail System”. The injection pressure easily exceeds the 1600 bar achieved in production cars. The ignition pressures also reach values never previously seen in any Audi engine.
The engine’s power and the high torque are available to the driver practically from idling speed – a speciality of diesel technology, to which the Audi drivers must now become accustomed. The usable power band lies between 3000 and 5000 revs per minute.


One of the diesel engine’s biggest advantages is the low fuel consumption, especially at part-throttle and overrun. However, when compared to more classic circuits which demand a higher ratio of part throttle, the lower specific consumption will hardly be noticeable at Le Mans because the quota of full-throttle is almost 75 percent.

The enormous torque of over 1,100 Newton metres not only posed previously unforeseen demands in the development of the R10 drive train. Even the latest generation of engine dynamometers at Audi Sport had to be reequipped with special gearboxes capable of withstanding the unusual forces.