For over 40 years, Active Autowerke has specialized in precision-engineered BMW performance parts. The Gen 2 Equal Length Mid Pipe continues that tradition, developed to enhance both sound and performance for the F80 M3 and F82/F83 M4 equipped with the S55 engine.
The S55’s twin-turbo design produces an uneven exhaust tone due to the unequal length of its front and rear downpipes—resulting in an unbalanced, high-pitched sound. Active Autowerke’s equal-length mid-pipe corrects this imbalance by precisely matching exhaust path lengths before merging them, creating a smoother, more authentic inline-six tone.
The unique sinusoidal crossover design equalizes exhaust pulse timing, eliminating the “weed eater” tone often associated with traditional mid-pipes. The result is a balanced exhaust note that closely resembles a naturally aspirated six-cylinder engine while improving turbo response and mid-range power.
For vehicles with catless downpipes, the resonated version is recommended to maintain optimal tone and minimize rasp. Testing was conducted with the factory rear section and the Active Autowerke MAAD MAXX exhaust system; results may vary with other aftermarket systems.
Key Features
- Equal-length design eliminates the pulsing sound from unequal downpipes
- Lighter than the factory mid-pipe
- Improved turbo spool and throttle response
- Enhanced low- and mid-range power
- Precision TIG-welded stainless steel construction
- Direct bolt-on installation, no cutting or welding required
Installation Manuals