BMW M3/M4 (F80, F82, F83) Post Cat Spare Pipes with Muffler Steering and Suspension At lower engine speeds and

At lower engine speeds and during cruise operation the valves are closed and produce a deeper exhaust note

Exclusive ability to switch between different 'modes' on the fly

and easiest to use ECU upgrade solution for your vehicle

This feature is possible using vacuum-actuated valve flaps that open and close depending on driving conditions and input from the driver

BMW M3/M4 (F80, F82, F83) Post Cat Spare Pipes with Muffler Steering and Suspension At lower engine speeds andBMW M3 M4 (F80, F82, F83) Post Cat Spare Pipes with Muffler The silencing effect of the OEM Spare Pipes and Resonator are reduced while maintaining a higher flow muffler and enhancing the car's naturally aggressive engine sound. Made from T309 (1. 4828) stainless steel.