Add dyno-proven power and unique sound to your BMW X5/X6 M with this Twisted Steel Race Series down-pipe that outflows and outperforms the factory down -pipe. Constructed from 3 1/2"-3" mandrel-bent, brush finished 304 stainless steel tubing to improve exhaust flow to deliver increased horsepower and torque. This one piece designed, direct fit down-pipe also features a factory-style V-band flange, heavy duty flex tube and factory O2 sensor and auxiliary ports so there is no modifying, cutting or drilling for a hassle-free installation. This down pipe is constructed of 3 ½-3" mandrel-bent, brush finished 304 stainless steel tubing for maximum flow, corrosion resistance and quality finish. Quality CNC machined, V-band flange mounts directly to the factory turbo for a leak-free sealing surface. 100% TIG-welded for race proven strength and durability. This one piece d esigned down-pipe features a factory-style V-band flange, heavy duty flex tube and factory O2 sensor and auxiliary ports so there is no modifying, cutting or drilling for a hassle-free installation. Twisted Steel 3-1/2 IN to 3 IN 304 Stainless Steel Race Series Down Pipe BMW X5 M (F85)/X6 M (F16/F86) 15-18 V8-4.4L (tt) S63 BMW X5 M (F85)/X6 M (F16/F86) 15-18 V8-4.4L (tt) S63