Modern technology, for your classic 911. Using wave cancellation to attenuate unwanted sound frequencies, while enhancing scavenging via pulse tuning, the Bisimoto Spec Pulse Chamber for the Porsche 911 SC and M491/M490 is an excellent choice. The result, a deep, throaty sound and documented 11-17 horsepower improvement with no other modifications. Unlike any muffler on the market, with over 15 pounds in weight savings compared to stock units. Made in the USA, from pure stainless steel, at a feathery 5 pounds.
For additional sound reduction, a new optional "arrestor" is available for an amazing 18+ decibel reduction in sound, without any horsepower penalty. Fully removable, with a 6mm bolt, for that race inspired tone, when desired. Modern day science, for your classic Porsche.
This is a manufacturing prototype (prototypes are typically used in in-house and field testing, and have medium weld aesthetics, irregular fit, and slight use). Option exists for a hanger to allow for bracing, if desired.