As I write, Audi has unveiled a new highperformance version of the TT at the Detroit show. It's called the TTS and houses a 2.0-liter, 265-hp TFSI engine that should propel it to 62 or so miles per hour in around 5.2 seconds.
I hate to break it to the guys in Ingolstadt, but I think I just drove a faster TT. This one comes not out of Germany but Northern California, from an operation in Sonoma called Stasis Engineering.
Regular readers will recognize the name. The company is renowned for optimizing chassis setups on Audi vehicles, derived from hundreds of hours of track testing at Infineon Raceway. Stasis likes to market its upgrades in complete packages, known as Signature Series, through established Audi dealerships with all the benefits implied therein: factory warranty, upgrade costs amortized into the sticker price, and so on.
The basic Signature Series power upgrade consists of updated ECU software and a stainless steel exhaust tract. The Challenge Edition TT pictured here gets both, along with a K04 turbo upgrade developed jointly by Stasis and Mahle Motorsport. The turbo assembly 48 europeancarweb.com is engineered to create high flow rates at low revs to simulate O.E. driveability while continuing to build over the factory power curve as engine speeds increase.
To support the turbocharger hardware, new injectors augment the fuel supply for the K04, which happens to be a bit thirstier than the stock unit. Stasis notes these squirters also provide the proper spray pattern for efficient combustion on a K04-equipped 2.0T.
The factory diverter valve is another weak point on the factory setup when dealing with higher boost levels. Stasis supplies a heavy-duty unit with the turbo package, as well as a relocation kit that moves the valve from in front of the turbocharger compressor housing (where it's vulnerable to withering heat) to further forward in the engine bay. The car also wears a Stasis stainless steel cat-back exhaust and a proprietary carbon fiber rear valance is provided to accommodate the central dual tailpipes.
Software programming falls to GIAC, detailed to Stasis specs that harvest the full benefit from the extra push of the turbocharger. The first examples must be re-flashed in-car, but Stasis is currently working on a special harness to bench-flash the ECU outside the car, meaning the computer can be sent abroad for programming instead of relying solely on authorized GIAC dealers for the update.