Rumors of the hottest TT variant ever are rampant. Several theories on drivetrain have resulted, though our money is on a turbocharged five cylinder. Volkswagen already does a low cost and lower capacity 5-cylinder with 2.5-liters, though an Audi version sharing very little with the base VW engine will be a considerably more costly and possibly a different displacement (we’ve heard 2.3-liters from one source) – built up to meet a power rating of 350-hp says a high-ranking source from Audi in Germany.
What else can we guess about the engine? FSI is a certainty, and Audi’s new Valvelift system is likely – aiding in both torque and fuel economy. 2.0T engines we’ve driven with the same FSI/Valvelift setup are burgeoning with torque and we expect no different from the TTRS’ five cylinder.
A turbocharged five-cylinder Audi engine in a performance coupe certainly pays homage to the original Quattro, though the TT’s transverse engine layout lower and closer to the center of the chassis, aluminum body structure and computer-controlled Haldex-sourced version of quattro will make it a decidedly different beast than the boxy Audi icon.
Details on the RS5 are less known, but strong theories are out there. S5 mules have been spotted testing in Europe well after the S5’s launch, and with the trademark RS oval tailpipes. They’re likely RS5 mules and we even hear that there may be an RS5 mule high altitude testing in America.
Print magazines have hinted at a number of engine directions – from the RS4’s high-revving 4.2-liter V8 carryover to the twin-turbocharged V10 of the RS 6 and everything in between. Here’s a quick rundown, supported with our own theories and comments shared by sources at Audi.
1. V10 Twin Turbo – This is an unlikely choice. Fitted in the RS 6, the engine forces pricing of the A6 variant into six-figure territory. Packaging might also prove difficult as the already sizeable V10 also has the turbo system’s plumbing.
2. V10 Normally Aspirated – The most recent issue of Road & Track raised this scenario. The American print magazine said sources close to the book have stated that Audi is working on a high-revving V10 FSI – what the RS4 4.2 is to normal 4.2 FSI, this engine would be to the S8’s V10. R&T’s suggestion points toward a shared approach with the upcoming R8 V10. That scenario doesn’t sound totally unbelievable and, should Audi be able to hit the magical100 hp/liter mark of the RS4, that would mean 520 hp. Still, one source at Audi says the V10’s fitment in the S5 chassis is unlikely but wouldn’t rule it out.
3. Forced Induction 4.2-liter FSI – Utter those words and people will immediately think of the last-generation RS6 and its twin turbo V8. The UK’s Car Magazine seems to think this scenario is most likely, suggesting 450 hp and 500 ft-lbs. of would could come from a mildly turboed RS4 engine.
Our own sources say this is unlikely in the details. First, the RS4’s high-revving setup likely wouldn’t get forced induction. Figure something more like the S5’s 4.2 FSI. If the next-generation S4 is supercharged says that source, then figure the lessons learned might be applied to other engines also. Fit a supercharger to the S5’s engine and the power figures suggested by Car aren’t out of reach.
4. V8 Normally Aspirated, RS4-spec – At 420 hp from 4.2-liters, the RS 4 engine is by far no slouch. Top Gear’s Jeremy Clarkson has raved about the mill, saying it might just be one of the best engines ever. Carrying over the engine lock, stock and barrel from the outgoing RS 4 is another possible scenario. No, it’s nothing new, but it’s still great and would be a ton of fun in the better-balanced B8-chassis coupe.