A normal exhaust’s main purpose is to extract the waste fumes from engine as smoothly as possible and to produce the least possible noise while doing so. In order for this to be achieved, the mufflers consist of a labyrinth of perforated filters wrapped in insulating material. This may significantly reduce the noise that the engine produces, but inevitably reduces the engine’s overall performance. On the other hand, performance exhausts are built in such way to maximize the free flow of gas fumes within them (and the performance of the engine), which also results in an increase in the sound that the engine produces.