According to info leaked from a reputable source at Audi, the new car will actually be powered by a 2.3L VR5 engine with a turbocharger. Final output will be 308hp (230kW), and the car won’t be called the TT-RS but simply TT-R. The engine will feature all the latest in Audi technology include new direct-injection as well as a fast-spooling turbo. This engine will also feature in multiple models in the Audi range apart from the TT.
Source: Motor Authority