Add dyno - proven power to your Mini Cooper with this Twisted Steel down - pipe which produced up to 16 horsepower and 20 lbs. x ft. torque max gains as measured on our in - house dyno. 3 to 2 - 34 mandrel - bent, 304 stainless steel tubing and high flow, 400 CPSI catalytic converter improves exhaust flow to deliver increased horsepower and torque. This direct bolt - on down - pipe requires no cutting or drilling and includes quality hardware for a hassle - free installation. Performance Gains In house dyno testing produced gains of up to 16 horsepower and 20 lbs. x ft. torque (tested with catalytic converter). Includes 3rd O2 bung This down pipe includes a 3rd O2 bung and plug for either a wide - band O2 gauge or auxiliary instrumentation. 304 Stainless Steel 3 - 2 - 34 mandrel - bent, 304 stainless steel tubing for maximum flow and corrosion resistance. High - Flow Catalytic Converter This system utilizes a 400 CPSI (cell per square inch) high flow catalytic converter for maximum flow. 6 Interlock Flex Pipes This unit utilizes heavy duty 6 flex tubes with internal interlock liners. CNC Machined Flange Quality CNC machined flange mounts directly to OE mounting locations for a leak - free sealing surface. Hassle - Free Installation Designed to be a true bolt on system with no cutting or modifications required. Quality hardware is included for a hassle - free installation. TIG - Welded 100 TIG - welded for race proven strength and durability. All aFe exhaust systems are engineered and manufactured in our Corona, California facility.