Audi Tests Diesel LeMans Racer
Audi’s new aluminum V12, twin-turbo-powered R10 racing sports prototype was unveiled in Paris and at the Los Angeles Auto Show in January. The engine makes more than 650 hp and runs on diesel fuel, and produces a massive 811 lb ft of torque. Audi’s previous R8 is a LeMans winner. Audi claims the 5.5-liter TDI engine is both quiet and fuel efficient. The day before the public showing in Paris , the car began winter testing at Sebring in Florida , along with other teams from the American LeMans Series.


Wider front wheels and a longer wheelbase mark new diesel R10 vs. gas R8

The new Audi R10 successfully completed its first test at the end of November. An extensive test program, including the 12-hour race at Sebring on 18 March, is scheduled before the 24 Hours of Le Mans in June 2006. The development team from Audi Sport is supported by Reinhold Joest’s squad, which also ran the R8 testing.

"With the A8 4.2 TDI quattro, Audi already builds one of the most powerful diesel cars in the world,” explains Prof. Dr. Martin Winterkorn, chairman of Audi. "The Le Mans project will help our technicians to extract even more from TDI technology.”

Two diesel particle filters, and injection pressure of more than 1600 bar are significant features of the diesel engine. For racing the engine’s best power range is from 3,000 to 5,000 rpm, which is more than half the speed of normal gasoline-powered racing engines. Because of the high torque output, drivers will need to change gears less often. The transmission had to be strengthened to handle the high torque output.



Audi reports that it had to modify its engine dynamometers to measure the high torque output of the engine, too. The racer’s engine, gearbox, and carbon-fiber frame are one fully stressed unit.

"The R10 project is the biggest challenge ever to have been handed to Audi Sport,” says Dr Wolfgang Ullrich, head of Audi motorsport. "TDI technology has not been pushed to its limits in motorsport yet. We are the first to confront the challenge. The demands of such a project are accordingly high. Long-term technology partners such as Bosch, Michelin or Shell support us in our quest. Together we have the chance to write new chapters in the history books of motorsport and diesel technology.”

The development team of Audi Sport runs two Audi R10 prototypes at Sebring. German Frank Biela and Italian Dindo Capello are driving the two cars. While Biela had completed the roll-out of the R10 in November 2005, Capello was at the steering wheel of the new diesel sports car for the first time at Sebring, where the two Audi drivers completed a total of 86 laps around the 3.7-mile circuit that is especially demanding for machinery due to its bumpy surface and is regarded as an ideal test track for a new race car. Furthermore, the newly developed V12 TDI engine faces its first test in high temperatures: While the previous tests in Europe were run in cool weather conditions, temperatures in Florida are reaching about 85 degrees in the shade.

On the second day of the Sebring test. Audi driver Capello gave the first glimpse of the new diesel sportscar’s potential: With his fastest lap of 1m 48.816s, the Audi driver dipped under last year’s pole position time by almost one second. Ulrich Baretzky, head of engines at Audi Sport, says “It wasn’t our target to set a competitive lap time at any cost here. For us it is a question of gathering data and to sort out the car. The time obviously shows that we are heading down the right path with the R10 concept. You have to take into account that this is only our third test with a completely new car. There’s a long way to go before Le Mans , it’s not just about doing one fast lap there, but reliability is of far more importance.”

Audi says the particulate filter-equipped R10 produced almost no smoke during the test.Baretzky: “From the very beginning it was our target that our diesel was unrecognizable, in much the same way as our production cars, as a diesel – particularly not by a cloud of smoke, but in fact through its low noise level, by its low consumption and its performance. Our goal was to develop a low emission diesel engine and we chose to go without one or two horsepower for the benefit of smoke free running. We are also using new particle filters here at Sebring for the first time, which have proven to be extremely effective till now. My colleagues from the chassis side aren’t quite as fond of them as they are actually fairly big. However, you come away with clean fingers even if you rub the tail pipe after 20 laps. This is exactly what we wanted to achieve. Our TDI engine is powerful and clean.”

“The R10 project is very ambitious, particularly as we have broken completely new ground, there were a lot of unanswered questions and there still are. In contrast to the development of the R8 we had the added advantage that we had gathered experience on the dynamometer, which we didn’t posses seven years ago. Here at the track, we can concentrate on things that could not be simulated on the dynamometer – including bumpy circuits and heat.”

“There were quite a few surprises – however, all mainly of a positive nature. The cooler configuration and the entire diesel fuel-system number among the things that can not be simulated on the test bench. You can’t simulate an engine cover or a headwind, a pit lane or the track temperature. You simply can’t simulate everything under a laboratory environment. You also need the track tests.”