Audi pushes for more technology inside the R18 – Mono-Turbo Tech for R18 TDI image

Lightweight design expertise expressed visually: This is the principle under which Audi enters the famous 24 Hours of Le Mans this year. Running in the highest-level class, LMP1, the R18 will be going directly after Peugeot 908.

Both of these cars run an extremely developed diesel engine , which works wonders for endurance racing.

Audi has chosen a particularly compact 3.7 liter V6 TDI engine, which is about 25 per cent lighter than the V10 TDI power plant previously fitted to the older R15 TDI, and which leaves all options open for the technicians with regard to electrification and energy recuperation.

“This would not be the case with a V8, for example, which is also permitted by the regulations,” explains Ulrich Baretzky, Head of Engine Development at Audi Sport.

In addition to the fact that the new unit will be 25 percent lighter than the V10 TDI previously used in the R15 TDI predecessor, it will also be coupled to a single turbocharger that “sits above the engine and draws its air directly through the air scoop mounted on the roof,” as shown in a recent statement from Audi.

The mono-turbo concept developed in cooperation with Garrett was only made possible by the variable turbine geometry (VTG) already used victoriously in the R15 TDI.

“Otherwise the response characteristics of such a large turbocharger would just be too bad,” explains Baretzky.

The concept was continued logically through a single pipe exhaust that exits at the rear of the R18 TDI below the new fin which is stipulated by the regulations.

“This also stands for Audi ultra lightweight technology,” says Baretzky, “since we save components and weight – for example for a second diesel particle filter.”

Another unique aspect of the new Le Mans sports car is its unusual sound. The Audi R18 TDI is probably the quietest race car Audi Sport has ever built.

“Noise is unused energy,” stresses Dr. Wolfgang Ullrich who is delighted by the whispering murmur of the R18 TDI. “The sound is unique,” raves Le Mans record winner Tom Kristensen. “It’s hard to describe. You have to hear it yourself. I think it’s fantastic.”