Aftermarket exhaust parts restrictions in the system—can similarly increase performance, though would likely be illegal in areas where tampering with emissions devices is prohibited, particularly when placed in front of the catalytic converters. Aftermarket exhaust parts Aftermarket exhaust parts are intended to replace the factory fitted exhaust components of a car, motorcycle, or other motor vehicle in order to improve the performance, visual appeal, or sound of the vehicle. Generally, performance enhancements are achieved by reducing the back pressure of the factory exhaust system. Frequently a side effect of a free-flowing exhaust system is either a "different" sound, a higher noise level, or
Exhaust brake over the wheels). See also Jake brake. Compression brakes, a form of engine brakes, produce greater noise pollution than exhaust brakes. For this reason, some vehicle original equipment manufacturers prefer to use exhaust brakes despite their lower braking power. Combining compression braking with exhaust braking can increase effectiveness without being as loud as compression brakes. Numerous cities, municipalities, states, and provinces ban the use of unmuffled compression brakes. Most exhaust brakes in the commercial market are protected by patents by companies such as GT Emissions Systems. The butterfly valve made up of acrylic material made in the circular shape, having