New Audi TT RS to dispense 300kW

It is yet to release its new RS 3 Sportback, but Audi has promised even more power and performance from the new TT RS super coupe that shares its engine.

Sources at Audi said this week that the hottest version of the just-launched compact TT coupe will come with more than 300kW – well up on the 270kW in the new RS 3 hot hatch and the 265kW of the previous RS TT Plus.

The two cars shared the same turbocharged direct-injection inline five-cylinder engine in the superseded generation, but this time around the coupe will receive significant upgrades.

It will get to 100km/h considerably quicker than the 4.3 seconds it takes the RS 3, the first generation of which was not sold in Australia, though it is expected to share the hatchback’s 280km/h optional top speed.

While Audi’s go-fast quattro GmbH division head honchos, Stephan Reil and Heinz Peter Hollerweger, refused to talk on the record about the fast-five coupe, insiders insist the car will deliver about 30kW more than the RS 3 five-door, which betters the 265kW/450Nm outputs of the Mercedes-Benz A 45 AMG hot hatch.

They also insist it will use the extra power to knock on the door of the four-second barrier for the sprint to 100km/h.

Reil — who wouldn’t even confirm the obvious inevitability of an RS version of the new TT, much less how much power it would have — said there would need to be a lot of work to get more performance out of the RS 3 engine, which produces 270kW and 470Nm.

“If you look at the performance curve, there are not many engines out there that can deliver this much torque (465Nm) at such a low rpm (1625rpm),” Reil said.

“But to do that the car is at the limit of the speed of the turbocharger now. The turbocharger is a relatively small one, for reasons of throttle response, and the performance in the RS 3 is at the limit of the rpms the turbocharger wheels can do in production,” he explained.

Nor would electronically boosting the crankshaft or turbocharger help a TT RS to climb beyond 400hp (about 300kW), he said.

"Well, the e-boosting we have shown on the RS 5 concept works very well with a diesel, but it’s not as effective on a gasoline engine,” Reil admitted.

“You would also have to package the system, including an additional 48-volt electrical system and another fast-discharge lithium-ion battery, and that would not be practical in a car the size of the TT.”

That leaves the new TT RS looking at a larger turbocharger with more scope for high-rev boosting to increase its mean effective cylinder pressure.

It would also give the TT RS a different character to the new RS 3, whose power delivery is more about an early punch with the boost tapering away as the revs rise.

Sources say the TT RS torque curve will still be strong down low, but its peak will arrive at least 400rpm upstream of the RS 3 curve and it will stretch its legs with a performance curve that prioritises greater strength at higher rpm.

While mainstream versions of the Audi's third-generation TT Coupe arrived here in February, the new TT Roadster and hotter S versions of the both the body styles go on sale here mid-year – around the same time as the blistering new RS 3 hot hatch.