Put in the simplest possible terms, a performance exhaust system replaces some or all of your car’s original exhaust system with improved pipework, silencers, and the like. As with most things in life, your car's original exhaust will have been a bit of a compromise. This means there are two big areas for improvement for performance exhaust makers – sound and performance.
The sound is one of the biggest pull factors for some owners. A performance exhaust can transform the sound of a car. The combination of pipework and silencers means each manufacturer can achieve their own trademark sound.
While you probably notice the very loud aftermarket exhausts more, there’s actually a whole range of sounds on offer, depending on who’s exhaust you are fitting to your car.
This can range from the very boisterous through to a refined performance car sound. Most manufacturers will have a consistent quality to their sound.
You may also have a choice of different sounding exhausts from the same manufacturer.
A better flowing exhaust can help your car to generate more BHP. How quickly you can get the exhaust gasses out of the engine places a limit on how quickly you can get fresh air into the engine and thus how much power can be made.
A better flowing exhaust always improves the power your engine can make. Performance exhausts achieve this in several ways. Pipework diameter, exhaust layout, and reducing obstructions in the exhaust all play their part.
On a non-turbo engine, it’s all about keeping the gas in the exhaust flowing quickly. The action of getting the exhaust gas out of the engine helps it draw in the fresh air at certain parts of the rev range.