Collector/Catalyst/Muffler Package: Racing Car Exhaust Noise Reduction

Significant reduction in the exhaust noise levels of racing cars has been achieved through the use of a special header-collector design. This design combines the primary header tubes, the collector, and the muffler into a compact package. The accommodation of exhaust systems on race cars -- especially those with mid or rear engine designs -- upsets the weight bias of the vehicle by moving the mass of the exhaust behind the rear axle, thus increasing the polar moment. The ducting of the exhaust to the rear also exposes vital components to extreme heat generated by the exhaust system. The CCM occupies fractionally more space than the header alone, allowing great flexibility in the design of the rest of the exhaust system. Testing has demonstrated that this design not only attenuates noise, but it provides increased horsepower and torque as well.