VRSF Race Downpipes BMW M550i 750i 850i N63R Heat ShieldVRSF Race Downpipes BMW M550i 750i 850i N63R Heat Shield (2017 2021) The N63R 4. 4L V8 twin turbo is one of BMW's most capable engines, and the factory downpipes are the first thing standing between it and its full potential. The VRSF Race Downpipes with heat shield eliminate that restriction with a smooth mandrel bent SS304 design, delivering 50 55 horsepower and 60 65 torque gains at the wheels when tuned, and an exhaust note that does the V8