The Non-Resonated Connecting Midpipe section of the Active Autowerke Equal Length Exhaust system.
Quality BMW performance products for over 39 years. Dedicated to improving enjoyment of your driving machine with the highest quality products, Active Autowerke has been recognized as the leading BMW innovator. Our philosophy on developing refined BMW performance parts and making them available to the larger BMW community is highlighted by our most recent R&D program focused on improving the sound of the S55 exhaust. This R&D has resulted in the development of the Active Autowerke Non Resonated Connecting Pipes (M3 & M4) for the F80 M3 and F82 M4 equal length mid-pipe (patent pending) – the other option to our world famous F8X single mid-pipe.
An inline 6 engine naturally has an evenly spaced exhaust pulse which results in a more smooth and full sounding noise. However, the twin turbo setup of the S55 engine while producing addition power has created a sound which sounds more like 2 independent inline 3’s competing for noise than the throaty sound one would expect. The variance between the lengths of the front and rear down-pipes of almost a foot and a half creates unevenly spaced pulses so that when the merge in any form of crossover system whether stock, x-pipes, double x-pipes, single mid-pipe or rear-section solutions. Since the sound waves are moving at the same rate when they exit the system, these crossover sections are simply creating a higher pitched sound resulting in the annoying sound some have referred to as a weed eater sound. The current systems allow the banks to merge unequally pulsed sounds and after much research and testing (from many BMW experts) it was determined that equalizing the length of the exhaust pipes before mixing was a solution to this sound problem.