Sportsman XR-1 Round 3.5in In/Outx15in Muffle Wheel Spacers The factory computer-controlled exhaust valve

The factory computer-controlled exhaust valve is eliminated

A thicker core would diminish airflow and sacrifice normal engine cooling which would be potentially detrimental to the long term health of the engine

Muffler - CrateMuffler - 2

The stock cooling system heat soaks after only 3 pulls and allows the engine air intake temperatures (IAT) to rise dangerously

Dinan also incorporates a Helmholtz chamber design that reduces resonance or'drone' at low RPM

Sportsman XR-1 Round 3.5in In/Outx15in Muffle Wheel Spacers The factory computer-controlled exhaust valveMuffler XR 1 Sportsman 3. 5 in Center Inlet 3. 5 in Center Outlet 15 x 5 in Round Body 20 in Long Stainless Natural Universal Each