Scott's 1997 C2S 3.8 Twin Turbo

Scott's C2S came to TurboKraft fitted with all the good stuff: genuine Ruf CTR2 front bumper, Aerokit-II (Turbo S) rear wing, Techart 19" 3-piece wheels, and Bilstein PSS9 adjustable coil-over suspension system.

The engine was equipped with an aftermarket supercharger conversion, complete with air-to-water intercooler and running 5.5psi boost.

Though the suspercharger's additional fuel system was "tuned" to the manufacturer's specifications, and the car was fitted with ideal bodywork for this conversion – a rear wing designed for maximize fresh air intake, and a front bumper that optimizes airflow to the intercooler's radiator – the performance was far short of advertised claims... It was not even as quick or as fast as a stock 993 Turbo.

Further inspection of the piston revealed signs of pre-detonation around the intake valves. Dyno testing showed air:fuel ratios in an acceptable range, but the ECU was all-stock, so no changes were made to the ignition timing maps. The knock sensors were functioning, but you cannot rely on the knock sensors alone to save the engine from self-destruction when the timing maps are wrong.

TurboKraft rebuilt the engine from the rods up, converting it to 3.8L displacement and twin turbochargers. The results are nothing short of breathtaking:

Rear wheel horsepower = 472.7hp @ 5,805rpm (approx. 540hp at the flywheel)

Rear wheel torque = 434.9tq @ 4,880rpm (approx. 500ft.lb. at the flywheel)

Maximum boost = only 10.5psi (0.72bar)
91-octane gasoline

Power output is almost twice that of a stock 993 C2S, and more than 125hp greater than a 993 Turbo, despite running the same boost pressure!

Thank you, Scott, for the opportunity to build you this awesome Turbo!