VRSF Race Downpipes BMW X5M X6M N63 S63 2-Bolt BrushedVRSF Race Downpipes BMW X5M X6M N63 & S63 (2 Bolt, Brushed) The S63 and N63 V8 twin turbo in the X5M and X6M is a serious engine, and the VRSF Race Downpipes are built to match. By eliminating the restriction in the factory downpipes and reducing back pressure, you get faster spool, 50 55 horsepower and 60 65 torque gains at the wheels when tuned, and an exhaust note that does justice to the V8 under the bonnet. Hand crafted from SS304 stainless steel