The Audi R15 TDI, commonly abbreviated to the R15, is a Le Mans Prototype (LMP) racing car constructed by the German car manufacturer Audi AG. It is the successor to the Audi R10 TDI.
Like its predecessor, the R15 TDI uses a turbocharged diesel engine, although the R15's V10 engine is physically smaller than the R10's V12. The smaller engine is pushed further toward the middle of the car than in the R10, resulting in a more neutral weight balance that gives the car better agility around the corners than its predecessor.
History
2009
The car was tested for the first time in December 2008 and made its competition debut at the 2009 12 Hours of Sebring race, 21 March 2009. The R15 got off to a perfect start by winning the 12 Hours of Sebring, setting a new race record in the process.
Three R15 TDIs participated in the 24 Hours of Le Mans in June 2009, under the control of Joest Racing. Peugeot, its rival, with its 908 HDi FAP, took the top two spots in the 24-hour race, ending Audi's five-win streak that lasted back to 2004 with the gasoline-powered R8.
Audi did not defend their American Le Mans Series, or Le Mans Series titles with the R15 TDI.
The R15 TDI features a Turbocharged Direct Injection (TDI) turbodiesel V10 engine, rated at over and of torque. The electrical system uses a lithium-ion battery, a first for Audi sports prototypes, as well as LED headlights and a unique system of LED rear lights that are mounted on the rear wing endplate.
In the week leading up to the 2009 24 Hours of Le Mans, rival Peugeot lodged a protest against the R15, claiming that its bodywork did not comply with regulations stating that parts of the bodywork cannot be fitted with the sole purpose of generating downforce. However, after the Wednesday free practice session, the ACO rejected Peugeot's protest. At the 2009 Le Mans, Audi was unable to continue its winning streak that dated back to 2004. The No. 3 R15 ran off at Indianapolis Corner at the beginning of the race but eventually finished 17th. The No. 2, driven by Luhr, crashed and retired. In the evening, the No. 1 Audi lost a lap to the leading Peugeot, which was faster, and further technical issues dropped it a full 7 laps down the order. The No. 1 Audi clinched a podium finish, finishing in third place.
Audi announced on 25 August, 2009, that two R15s would race at the 2009 Petit Le Mans. Both Audis led for approximately 90% of the race, but a late spin during the final rain-soaked caution handed the victory to one of the Peugeot 908 HDi FAPs entered by Team Peugeot Total. This loss was Audi's first since competing in Petit Le Mans since their initial attempt at Road Atlanta back in 2000.
R15 TDI Plus (2010)
In response to losing the 24 Hours of Le Mans and the Petit Le Mans to the Peugeot 908s, Audi updated their R15 for the 2010 season, creating the R15 Plus. 2010 regulations reduced the size of diesel LMP1 air restrictors and turbocharger boost pressure. However, despite this, Audi's engineering team, led by Ulrich Baretzky, was able to achieve engine power and performance that was comparable to the 2009 powerplant. Aerodynamic efficiency was also a major area of focus in 2010. The frontal area of the car was redesigned to reveal the raw crash structures. The front fenders were also lowered in an effort to reduce drag, while the concept of air running through the car was abandoned for a more conventional design. The air channel that exited to the side of the car was redesigned, resulting in a more conventional configuration, and a new headlight concept was introduced. Audi stated that they had improved the fuel tank and cooling system as well.
Racing history
The new vehicle was a success at the 2010 8 Hours of Le Castellet, winning five laps ahead of the next competitor, Aston Martin. The Oreca Peugeot, which was supposedly its rival, dropped a full eight laps down the order because the airjacks failed to come off. Audi continued to go flat out and, in the end, finished ten laps ahead of the Peugeot. Audi had now been able to achieve both the speed and reliability combination that they considered sufficient to match the Peugeot challenge for Le Mans. A full squad of three cars was entered for the next race, which was the 2010 Spa 1000 km, finishing third (#7, behind the two Peugeots - No. 3 took first, No. 2 took second), fifth (#9), and twelfth (#8), respectively. Audi treated the race as a setup exercise for car configuration at Spa that would then be used for the 2010 24 Hours of Le Mans.