These 100% SS, mandrel bent, CNC cut headers by Supersprint are one of the best header options available for your M3! Supersprint has developed these headers through extensive dyno testing to ensure maximum power gains. The stock manifold is designed for maximum emissions efficiency and sound restriction so it hinders performance. Switching to a well designed header, such as this Supersprint unit, will allow your engine to release exhaust gases as efficiently as possible which will increase your horsepower and torque!