Billy Boat Performance Mufflers - Touring Sound

Reduced backpressure gives your BMW an instant horsepower boost! The stock BMW muffler has a vacuum-activated butterfly valve on the driver's side muffler. This valve is closed under most conditions, diverting all exhaust gases to the passenger's side tailpipe. Under certain conditions (e.g. high throttle/low vacuum), the butterfly valve opens so two mufflers can be used. The Touring version of our Tri Flo exhaust duplicates the actuator and butterfly valve, so it operates in the same way as the stock exhaust. However, the muli-chambered design of our Tri Flo allows exhaust gasses to flow more freely. The result is a slight increase in horsepower and a more resonant sound when the butterfly valve is closed, but a bigger boost in power and a throaty growl when you hit the throttle hard. (For an even more aggressive sound, consider the Sport version of this exhaust which eliminates the actuator and valve.) Stainless steel construction. Limited lifetime warranty. Simple Cut/Clamp installation. Includes left and right mufflers.

Check out the sound clip on Youtube