Patent ID: 8746401

Claim:
A muffler for raising an audible pitch of an internal combustion engine's exhaust note, comprising: an enclosed case having an inlet and an outlet; and a plurality of flow-directing components adapted to subdivide an inlet flow into a plurality of discrete interior flows comprising: a first discrete interior flow passage providing the shortest flow length through the enclosed case between the inlet and the outlet; a second discrete interior flow passage between the inlet and the outlet and having a flow length at least about twice the flow length of the first interior flow passage; and at least one discrete intermediate interior flow passage following a by-pass passage, and wherein the at least one intermediate interior flow passage splits off from the second interior flow passage between the inlet and the outlet; wherein the plurality of flow-directing components comprises: a plurality of interior deflector assemblies, each spanning a distance between a top and a bottom of the enclosed case and comprising a parallel surface and a transverse surface extending from a backside of the parallel surface, and at least one side deflector assembly spanning a distance between a top and a bottom of the enclosed case and extending from a sidewall of the enclosed case into a gap between the transverse surfaces of at least two of the plurality of interior deflector assemblies to form the tortuous passage for the second interior flow passage.