Techart has worked its magic, yet again, on the 997 Porsche 911 Turbo, boosting output of the twin-turbo'd flat-six to 660 hp and 634 lb.-ft. of torque. The Techart GTstreet R benefits from a duo of new turbos, larger carbon fiber inlet pipes, revised intercoolers and a new cat-back exhaust mated to the revised manifold which all help to drop the 997's 0-60 time to 3.4 seconds when equipped with an auto 'box and 3.5 seconds with a manual. Top speed is a claimed 214 mph.

Click above for a high resolution gallery of the Roock RST 600 LM

Click above for our high-res gallery of the Hamann Stallion

You wouldn't be mistaken for thinking that the Porsche 911 Turbo was already one of the fastest, best-performing sportscars on the road today. But that's where uber-tuners like Hamann - who've tuned everything from the MINI Cooper to the Ferrari 612 Scaglietti - come in to confound expectations and shatter assumptions.

Photo by Bruce Benedict