Following the great styling of the 2 into 2 exhaust system found on the XR 750 factory racers, SuperTrapp designed this exhaust system for Evolution Sportsters. Although specifically designed for the 1993 dirt track series, it is totally streetable as well. Dyno testing on a stock 883 (rejetted and different ignition module) showed a peak power increase of eight Horsepower!!! Installation on modified Sportsters (Big- Bore, cams, carburetor, head work, etc.) and the use of up-to 28 discs will yield an even more dramatic power increase. This system is supplied with twelve discs per megaphone and comes complete with 2.5" diameter reverse-cone racing cores. As a note, even though we all know our Harley/SuperTrapp customers love the roaring thunder of their motorcycles, the use of 15 to 28 discs and/or the open racing style end cap will make this system louder than other SuperTrapp Megaphone-style systems.