The team at Heffner Performance have finally completed their initial Stage 1 twin-turbo package for the Audi R8. Running on pump gas and using just 6 psi of boost, the two turbochargers boost output from the 4.2-liter V8 engine from 353 rwhp to 536 rwhp, a gain of over 50 percent. A more powerful 100 octane version is also being worked on which is expected to produce in excess of 600-hp. In addition, Heffner also plans twin-turbo applications for the V10-powered R8.
The Heffner car is actually not the first turbocharged Audi R8. The first such car was built by German Audi tuner MTM for a private client in the Middle East. It was a matte-black car that reportedly made 888-hp and debuted at the Dubai Auto Show several years ago.
Heffner Performance is well-known in elite tuning circles for twin-turbo applications for the Dodge Viper, Lamborghini Gallardo and Ford GT.
See after the jump for a dyno graph: