If you were going to design a sports car, you wouldn’t start with the layout of the Audi TT. You wouldn’t choose a front-wheel-drive architecture. You wouldn’t turn the engine sideways, and you damn sure wouldn’t locate it ahead of the front axle.
Instead, you’d start with a rear-wheel drive platform, mount the engine longitudinally, and keep it behind the front axle. Heck, you might even use a mid-engine layout.
You’d do all this with the aim of creating a perfect 50/50 weight balance front to rear. You’d be alright with a 40/60 rear weight bias in a mid-engine car, but you would cringe at the idea of the 59/41 front bias you get with the 2018 Audi TT RS.
And yet it works.
The TT RS is the sportiest and most powerful version of the TT sports car. While Audi is building both coupe and convertible versions, we only get the coupe.
We’ve driven the base TT and and the more powerful TTS and found them to be fun, but flawed. The TT RS adds a heaping helping of performance equipment to make it both fast in a straight line and capable on a racetrack.
The meanest TT
It all starts under the hood where the engine sits in the wrong place facing the wrong direction. That engine is a turbocharged 5-cylinder, an Audi oddity that dates back to the 1970s. The previous version, which was last offered for the 2013 model year, maxed out at 360 horsepower. This almost entirely new version huffs out 400 hp and 354 pound-feet of torque; the latter is available from 1,700 to 5,850 rpm. At 160 horsepower per liter, the specific output of the TT RS is bested by only a handful of cars, most of them supercars.
2018 Audi RS 3 and TT RS at Lime Rock ParkEnlarge Photo
Audi threw quite a bit of technology at the engine to make it lighter and more powerful. The block changes from iron to aluminum and sheds 40 pounds in the process. A new crankshaft with lightening holes shaves 3.1 pounds and spins with less friction loss, while a new magnesium oil sump cover cuts another 4.4 pounds. All told, the engine is 57 pounds lighter, helping to improve that weight balance from a little over 60 percent front/40 percent rear to 59/41. It’s small, but it helps.
Internally, the engine adds port injection to the existing direct injection to improve low-speed emissions and add a bit of power during hard acceleration. Turbo boost improves from 18.4 psi to 19.6 psi. Audi also adds variable valve lift on the exhaust side with two profiles, one to improve fuel economy at low speeds and the other to improve throttle response during hard acceleration. All this work helps improve horsepower by 17 percent.
The engine is mated to just one transmission, Audi’s 7-speed dual-clutch S Tronic. It has one more gear than the version in the TT and TTS and can be shifted manually via steering wheel paddles.