Active Exhaust for Headers
MKM34STAE – Active Exhaust for Headers, 911S Tailpipes. $1995
MKM29STAE – Active Exhaust for Headers, 911GT3 Tailpipes. $1995
Now you can have the sound and performance of a Sport muffler combined with the tranquility of our Street muffler! Our Active Exhaust System for Headers is a true dual function muffler. At idle and cruise the exhaust flows through the STREET MODE path giving a nice tone that is a little louder than stock so you can enjoy that flat six sound while carrying on a conversion in the cockpit. Step on the gas and the vacuum operated valves open diverting flow to SPORT MODE. This path relieves back pressure allowing full use of tuned headers for the power and sound you expect out of your Porsche at speed!
Dump pipes are adjustable and can be pointed out where they are seen or pointed down where they are hidden behind the valance. These mufflers are designed for use on G-body impact bumper 911 but can be used on Early 911 or 914/6 with modifications to the dump pipes. Optimum power is achieved when combining with our Tuned Headers. Not recommended for use with carburetors or intakes that reduce the vacuum signal produced by the engine. Minimum of 12″ vac required to fully close the valves. Valve cracking pressure is adjustable and may be adjusted to compensate if vac levels are close to minimum. Custom Valances are available for use with this muffler. Active Exhaust Mufflers for Headers come in either 911S (tailpipes 11″ on center) or 911GT3 (dual center out) configuration. Call for custom spacing options. Muffler comes with all hardware to install and make fully operational. These mufflers are build to order. Please allow 1-6 weeks to ship, call if lead time is an issue.