Techart GTstreet RTechart has done best again and presented a tuned package of the 997 Porsche 911 Turbo, increasing output of a twin-turbo flat six to 660 horsepower (485 kW) and 634 lbft (860 Nm) of the torque.The revised intercoolers, double new turbos, bigger carbon fiber inlet pipes and fresh exhaust mated to improved manifold, all help to decrease the 997’s 0 to 60s to 3.4 seconds when