What we know is that the 2009 Audi TT-RS will be the top of the line model in the lineup.For now,the TT-RS is under development at Audi’s Ingolstadt headquarters in Southern Germany.It is expected that the TT-RS to be an important rival for coupes like BMW Z4 M and Porsche Cayman S.

Rather than the 3.6-liter V6 engine as widely rumored, Inside Line can confirm the range-topping TT is set to become the first Audi model to receive a new turbocharged version of parent company Volkswagen’s long running 2.5-liter five-cylinder as found in North American versions of the Jetta.

Updated to accept the same cylinder head configuration as the 5.2-liter V10 used in the S8 along with the latest direct-injection technology from German specialist Bosch, the new Audi engine is said to deliver in the region of 365 hp. That’s some 22 hp more than the Z4 M Coupe.