Active Autowerke Gen 2 Equal Length Mid Pipe - F8X M3 / M4

  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 mai