Banks Monster exhaust outflows stock and the competition. The streamlined 4" turbine-outlet pipe, intermediate pipe and tailpipe are formed of stainless, heavy-wall tubing with constant-diameter bends to slash backpressure. Banks replaces the factory's restrictive muffler with Banks' polished-stainless steel Monster muffler, featuring a straight-through 4"-diameter flow-path with Banks' designed expansion chamber which dissipates the annoying mid-range exhaust