Break err Or You could say BURN IN. Heat causes some of the sound dampening material to either burn off or compress causing the Exhaust to get Louder than when it's first put in. Just Listen to a Thermal exhaust or sebring. They are Somewhat softer when new but get Extreemly LOUD when Old. If the Resonator your using is either packed with Fiber glass or rock Wool after a while all the stuff gets burned out OR BLOWN OUT.

NismoCPV-35