After months of testing this system with various size piping the engineering team decided that 3.5” piping is the best suited size for a true free flowing design on the 135. The increase in piping size decreases back pressure allowing the 135’s twin turbo to spool even faster resulting in increased horsepower and torque throughout the entire RPM range.
The engineering team also incorporated the Active Autowerke Noise Cancellation Chamber to assist in reducing/eliminating drone. Manufactured from 100% polished 304 stainless steel, this bolt on system is a must for the 135 owners looking to bring their BMW to new heights.
Since 1981, Active Autowerke has been known as the BMW innovators when it comes to BMW performance. All products come with a 2 Year Warranty.