The exhaust system of a vehicle carries exhaust gases out of an internal combustion engine. The exhaust gases are typically ported through a catalytic converter to a muffler, after which they exit through the tail pipes. The catalytic converter uses high temperatures to reduce noxious gasses from being emitted by the combustion processes. The muffler uses sound resonance and possibly sound damping materials to reduce or alter the sound profile of the exhaust system. The tailpipe releases the gases and is the primary location of sound output. Quieting an exhaust system requires alteration of the exhaust components or restriction of sound waves to the vehicle cab.
Install a different muffler. The muffler is the point at which the exhaust gases converge and can be physically damped or reduced through baffling and chambers. Chambers allow the sound waves to be reflected, damped and collided, reducing total sound output. If running a dual exhaust system (whereby the exhaust output from the engine cylinders is split down two paths), you can port the exhaust into a dual-in muffler. The exhaust sounds in a dual-in muffler will collide and mellow the overall sound. Select a muffler designed to reduce the noise output.
Wrap the muffler with sound-damping high-temperature wrap. Exhaust wraps with sound-damping capability will reduce the vibrations transferred to the vehicle and may assist in damping the sound that's allowed to travel to the exhaust pipe.
Install a layer of sound damping pads in the cabin of the vehicle. Sheets of material designed for acoustic damping reduce external vibrations and sounds. Install acoustic damping materials under the carpet layer, in the doors and between the metal surfaces and any upholstery. Acoustic damping materials not only damp exhaust sound in the cabin but also decrease road noise and add clarity to interior sounds.
Install a resonated exhaust tip. Resonated tips are lined with fibreglass or other sound damping material and are installed at the exhaust pipe. Sound waves passing through the resonated tip are absorbed by the liner and reduce the overall sound output of the exhaust.
If your vehicle has an installed dual exhaust system and you do not wish to exchange the muffler or install a new system, a cross pipe can be installed to connect the pipes prior to their connection at the muffler. A cross pipe allows the exhaust gasses to travel between the two exhaust sets and damp, smooth or mellow the exhaust output.
Installing exhaust wraps around a muffler may increase temperatures within the muffler. Exhaust baffles exposed to higher temperatures may degrade faster or create burning odours.