Alcohol race mufflers incorporate strategically placed "burn holes" inside the muffler in all of the low-pressure areas to prevent damage from excess methanol fuel from puddling and backfiring on deceleration. Through years of racing and partnerships with leading race sanctioning bodies, Flowmaster has developed these specialty mufflers that have been specifically engineered for race vehicles in organizations such as NASCAR, ARCA, and the W.O.O. sprint car series. These include race mufflers for low ground clearance, special race fuels, packaging restraints, etc.