A high performance muffler, e.g., for an internal combustion engine, reduces
exhaust
or other gas noise while maintaining a low backpressure to prevent engine power
loss. A side inlet pipe connects gas to a muffler body. The inlet pipe is flared
at its connection to the muffler body to direct flow of the gas through an inlet
chamber of the muffler in a spiral path. In an example embodiment, the muffler
body includes three chambers separated by panels. An inlet expansion chamber is
adjacent to the inlet and includes a first pipe with a perforated portion. An intermediate
expansion chamber adjacent to the inlet chamber receives the gas from the first
pipe. Four small pipes at the exit end of the intermediate chamber extend into
an outlet expansion chamber. The gas in the outlet expansion chamber exits the
muffler body by an outlet pipe at the other end of the outlet expansion chamber.
The muffler achieves a high sound reduction without increasing backpressure.
