Since 2011, customer racing activities have included the TT RS. The compact race car was developed in accordance with the SP4T rules of the VLN (Veranstaltergemeinschaft Langstreckenmeisterschaft Nürburgring). They permit extensive modifications to production-based vehicles, provided the fundamental character of the original model is retained. For example, a thoroughbred race car engine may be developed, or the production engine may be modified.
Audi chose the series production basis as an ultra-modern engine suitable for motor sports was available as the new 2.5 litre five-cylinder engine in the TT RS. For racing, output was boosted by 29 kW to 279 kW (380 hp). Crank drive, valve drive and crankcase all remain unchanged from the series production engine, as does the cylinder head. The increase in power over the series production unit is primarily the result of a reprogramming of the control unit and of a racing exhaust system. A new cooling system was also installed to cope with the increased thermal demands.
The Audi TT RS is equipped as standard with the quattro permanent four-wheel drive system. Because most race series prohibit four-wheel drive systems, Audi built probably the most powerful front-wheel drive racing car in the world. The control of the sequential six-speed gearbox and the pneumatic shift actuation were adapted from the Audi R8 LMS. While the three-plate sintered metal clutch is a pure racing module, the propeller shafts were combined completely from series production components. For example, the outer joints come from the Audi Q7 V12 TDI.
The TT RS also benefits from the Audi R8 LMS braking system: the complete front brake assembly was adopted, while the rear brake discs are taken from the production TT parts bin. The GT3 race car’s front wheels are used at all four corners. The body features a safety cage, while the roof and rear side panels remain standard production components. The underbody, doors and bonnet are made of CFRP, while the front wings, side sills and rear body extensions are made of GFRP. All windows are made from Makrolon, and the racing seat shell is also sourced from the Audi R8 LMS.