One squeeze of the new Audi TT RS’s right pedal is all it takes to know what’s most special about the car. That inline five-cylinder is an Audi hallmark that’s featured in everything from its greatest racecars to humble passenger sedans.
In the TT RS, the 2480cc turbocharged unit is now at the top of its game. Spinning up 294kW at 5850rpm and 480Nm at 1700rpm, it packs a heavy punch.
It’s also very new. At the vehicle’s launch we had the chance to mingle with the engineers and learn some interesting things about it.
For instance, did you know its turbocharger’s turbine now flows in reverse? Nope? Then here's five nerdy things about the new TT RS’s engine…
1. It’s been on a serious diet
While the block design’s largely the same, alloy construction pulls 18kg from the old cast-iron case, while a hollow steel crankshaft rids another 1.4kg from its rotating assembly.
Lightweight pulleys do their bit, as do smaller main bearings and the magnesium oil sump top, which finds another two kilograms. Overall the new engine is 26kg lighter, totalling at 157kg.
2. It no longer has a cool red cylinder head
Pop the new TT RS’s bonnet and you won’t be greeted by a gleaming red cylinder head like in the original 2009 model. Audi hasn't painted it this time round and even hidden it with a cover. The engine’s swapped to a higher-pressure dual-injection system, which required new wiring and piping deemed too ugly for your eyes.
3. There’s a whole new turbocharger system
Audi’s enlisted a completely new turbocharger system for the second-generation engine. The new Borgwarner unit is bigger, and now crams 1.35 bar (19.6psi) into the cylinder whereas the old snail ran at 17.4psi.
While still single-scroll (as it must be with a five-cylinder), the exhaust flow’s direction has been reversed so gases hit the turbine’s fins straight on to help spool and response.
4. It’s technically related to a Rabbit
The old TT RS’s iron-block turbo five was essentially a tweaked and turbocharged version of what was found in the US market’s Rabbit (also known as the Golf). Both blocks share the same undersquare bore (82.5mm) and stroke (92.8mm) measurements with the new alloy unit, however this latest case’s alloy design evolves the iconic five-cylinder even further.
5. It can handle 447kW... we suspectAudi extracted 447kW from the old iron block in the TT Clubsport concept wheeled out at Worthersee last year. When asked whether the new alloy engine could withstand the same sort of power Philipp Ade, a powertrain engineer, smiled and said, “I can’t answer this question”, before bursting with laughter. Not a yes, but then again, hardly a no either.
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