An exhaust system is usually piping used to guide reaction exhaust gases away from a controlled combustion inside an engine or stove. The entire system conveys burnt gases from the engine and includes one or more exhaust pipes. Depending on the overall system design, the exhaust gas may flow through one or more of:
- Manifold or Header
- Crossover Pipe
- Catalytic Converter
- Exhaust Pipe
- Tail Pipe
The intent of an aftermarket component is not necessarily to modify the appearance, sound, or performance of the vehicle in question. While that is almost
Always the goal if the aftermarket component is replacing a fully working component, it is frequently the case that when the stock or factory component has
Worn out that an aftermarket component is either more widely available or less expensive than a factory or OEM replacement.
Catalytic converters are necessary to reduce emissions but create back pressure due to the exhaust gases being forced through a catalyst, and therefore decrease high-end engine power. Many modern catalytic converters only produce 1-3 psi of back pressure, though this restriction worsens further with use. Hi-flow catalytic converters can replace the standard units in order to provide lower backpressure. Installing aftermarket catalytic converters is restricted by law in some countries, with bolt-on straight ‘test pipes’ available to test whether a clogged catalytic converter is causing problems, which can be easily swapped out for on-road use or scheduled emissions testing. Hollowing out a catalytic converter is unlikely to give power gains unless a pipe is placed through the converter to give a clear path for exhaust gasses.
The section of tubing between the catalytic converter(s) and the rear muffler on cars that have two parallel exhaust pipes. Performance mid-pipes often have a perpendicular connecting pipe or the pipes temporarily merge. This is to equalize the pressure in both exhaust pipes.
H-Style Pipe where there is a perpendicular connecting pipe, resembling the letter H
X-Style Pipe or X-Pipe where the exhaust pipes temporarily merge, resembling the letter X
Glasspacks employ two tubes, an inner perforated one, and an outer solid one. Between these tubes, there is sound insulation. These mufflers decrease back pressure, but are relatively ineffective at reducing sound levels. Glasspacks can be used to give the engine a deeper “throaty” sound.
Resonators are sections of exhaust pipe that expand to a larger diameter and allow the sound waves to reflect off the walls and cancel out.
Resonators are mostly used to reduce raspiness and popping. They do not produce much back pressure.
Many North-American cars (and possibly cars in other parts of the world) made since the early to mid-1990s can have up to 3 distinct (but similar looking) exhaust components downstream from the catalytic converter(s). Each of these components may be called resonators or mufflers. Usually only the last component is the actual muffler, and the other components are the resonators.
The piping that connects all of the individual components of the exhaust system is called the exhaust pipe. Contrary to popular belief, the largest diameter exhaust pipe is not always better. If the pipe is too large, the scavenging effect will suffer at low rpm, resulting in loss of torque and driveability. Running a pipe that is too large may also decrease a car’s ground clearance, increasing the risk of the exhaust being damaged when the car moves over an uneven surface.
Stock mufflers typically bounce sound waves off of the back, front, and sides to cancel out sound. They also increase back pressure, but are very effective at reducing the sound levels.
Mufflers are a series of concentric or eccentric pipes inside the expansion chamber cavity. These pipes allow sound to travel into them and cause the sound waves to bounce off the closed, flat, ends of the pipe. This reverses the direction of the sound waves making them collide with oncoming sound waves and cancel each other out. This design is usually very free-flowing but does not offer as much sound reduction as a muffler002E