Huge 4-inch constant-diameter mandrel-bent stainless steel pipe outflows stock by 26 Percent. Straight-through muffler virtually eliminates backpressure. Retains factory catalytic converter. Includes Turbine Outlet Pipe and 5-inch Chrome polished tip. Stainless, 4-inch constant-diameter pipes and straight-through muffler outflow stock. Virtually eliminates backpressure and lowers exhaust gas temps. Throaty sound. 5-inch polished tip. 100 percent stainless system extends engine longevity by maintaining the turbine outlet EGT safely within the stock recommendation. The 3-inch Turbine Outlet Pipe, which replaces the smashed stock piece (see below), flows 728 CFM at 1 PSI, beating stock by 26 percent and the nearest competitor by 12 percent. The streamlined 4-inch exhaust pipe and tailpipe are formed of heavy-wall tubing with constant-diameter bends to slash backpressure.