VRSF Race Downpipes BMW M550i 750i 850i N63R BrushedVRSF Race Downpipes BMW M550i 750i 850i N63R Brushed (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 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 finally does the V8 justice. No necking