Add more power and sound to your Challenger with this MACH Force - Xp cat - back system which produced gains of up to 13 horsepower and 15 lbs. x ft. torque as measured on our in - house dyno. Dual 3 mandrel - bent, MIG welded, 304 stainless steel tubing with X - pipe and crossover balance tube keeps exhaust flowing smoothly and evenly for power gains you can feel and hear. This system utilizes the factory exhaust valve motor and spherical clamps are used to retain the factory tips for a stock appearance. Dual stainless steel, high flow mufflers finished in high temp powder coating deliver an aggressive, performance exhaust note.