Valvetronic Design Porsche 997 Carrera Valved Sport Exhaust systemWelcome to the Valvetronic Designs Valved Sport Exhaust for the 997 Platform. This system has been designed from the ground up to give very rich F1 sound and to provide minimal frequencies when running in the valves closed mode. This 997 system from Valvetronic Designs delivers the ultimate Porsche experience. Due to the unique configuration of the exhaust system, when equipped, your car will sound unlike any 997 out there. The FreeFlow nature of the