Patent ID: 6889499

Claim:
An exhaust system for a multi-cylinder engine, the system comprising: a plurality of exhaust ports, each in communication with a cylinder of the engine to discharge a pulse of exhaust gas; a plurality of primary exhaust pipes, each having an inlet end and an outlet end, wherein the inlet end is connected to one of the plurality of exhaust ports to scavenge the pulse of exhaust gas; two collector chambers, each connected to and in flow communication with at least one outlet end of the plurality of primary exhaust pipes, wherein the two collector chambers alternate in their collection of subsequent discharges of the pulse of exhaust gas from the engine; two secondary exhaust pipes, each connected to and in flow communication with one of the collector chambers; and a muffler housing, wherein the muffler housing encloses: a diverter subassembly, wherein the diverter subassembly comprises: a first inlet pipe and a second inlet pipe connected to and in flow communication with the two secondary exhaust pipes; a gas decelerator chamber connected to and in flow communication with the first and second inlet pipes, wherein the alignment of the first and second inlet pipes directs the pulse of exhaust gas onto a flow splitter in the gas decelerator chamber, wherein the flow splitter is located obliquely to the flow direction of the pulse of exhaust gas and divides the pulse of exhaust gas; and a first outlet pipe and a second outlet pipe connected to and in flow communication with the gas decelerator chamber, wherein the two outlet pipes direct the divided pulse of exhaust gas away from the flow splitter forming a low-pressure zone in the wake of the pulse of exhaust gas, and wherein the low-pressure zone preferentially travels back up the exhaust system as a reflected negative wave to scavenge the subsequent pulse of exhaust gas; a plurality of cores connected to and in flow communication with the first and second outlet pipes, wherein each core is perforated or louvered to swirl the divided pulse of exhaust gas as it travels through each core; a dead air space chamber connected to and in flow communication with the plurality of cores; and a plurality of muffler outlets connected to and in flow communication with the dead air space chamber and configured to expel the exhaust gases out of the muffler housing and into the atmosphere.