Made of more than a dozen components, the exhaust is one of the most important systems when it comes to emissions, noise and performance. This is because the fumes generated by the engine enter the exhaust through the manifold, also referred to as a header.
Once they've passed the tubed component, they then encounter the O2 or oxygen sensor which measures the amount of oxygen in the fumes. This info helps the ECU correct the air and fuel mixture accordingly. After that, the fumes or gasses go through the catalytic converter which helps take care of emissions. Then they enter the muffler which reduces loud noises and then the gasses exit out through the tailpipe(s).
Benefits of a Performance Exhaust
HP
An improvement in HP doesn't only come from an engine upgrade, a performance exhaust can also deliver an increase in HP and torque (to a certain extent). This is mainly thanks to the dimensions and material an aftermarket sports exhaust is made of which can help free up the flow of gasses thus unburdening the engine.
Efficiency
You may not get an improvement in fuel economy with a performance exhaust but you'll definitely have a more efficient use of fuel. That's all because of airflow since a less restrictive system makes it easier for the O2 sensor to do its job and make the engine run with a more accurate mixture of air and fuel.
Longevity
The improved use of fuel makes for not only a more efficient vehicle but also one that will potentially run longer. I say potentially because it also depends on how well you maintain your vehicle and not just the quality of the parts you put in it.
Sound
Changing the way your car deals with the engine's fumes changes the way it sounds as the fumes get out of the engine's exhaust port in a slightly different way. This can be altered with just a different muffler but it's not as beneficial as a whole new exhaust system since it doesn't affect performance as much.
Appearance
Despite being on the undercarriage and thus mostly hidden, a new aftermarket exhaust can influence how your car looks thanks to one or multiple components sticking out at the back. The tailpipes can easily make your car look the part or like every commuter on the road, it's totally up to you.
Types of Performance Exhausts
Cat-Back
The most tamed performance exhaust you can get is a cat-back exhaust and that's simply because it replaces the smallest number of components. That's the cat, the pipe that connects it to the muffler, the muffler, the pipes that connect the muffler to the tailpipes and the tailpipes. The simplicity is what makes a cat-back popular, not the performance gains which are mild.
Turbo-Back
A turbo-back exhaust is the complete opposite of a cat-back exhaust since it replaces the whole system as well as the turbo. As you would expect, this is the best performance solution if you have a turbocharged engine as with it, you're able to get a truly custom exhaust and turbo. Both a new turbo and exhaust bring an immense performance boost but also cost quite a bit.
Header-Back
If you don't want to replace the turbocharger or have a naturally aspirated engine then a header-back exhaust is better suited. It still offers better performance improvements than a cat-back exhaust, it just doesn't cost as much as a turbo-back system. You still get an impressive bump in performance both on and off the track as you're still installing a whole new sports exhaust.
Materials
Titanium
A titanium exhaust is what you should aim for if you have the assets for it as well as the need to go around a track as many times as possible. That's because a titanium exhaust has excellent thermal resistance and stability while being strong, light and corrosion resistant.
Stainless Steel
With stainless steel exhausts, you may not get as ideal of a solution for track use, but you still get a great alternative to titanium exhausts. Stainless steel is light and strong and it has excellent corrosion resistance but it's not as good at handling high heat levels as titanium.
Inconel
The ultimate material when it comes to performance is Inconel. If you can get your hands on such a car exhaust you're essentially holding the holy grail of exhausts as it's nearly impossible to get one. That's because most of them go on Formula 1 cars.
Factors to Consider
Diameter
The dimensions you need to worry about regarding a performance exhaust are the diameter or size of the piping. It's simple though, the larger the pipes the more gasses can pass through at once, which equates to every 100 HP you just add an inch in diameter.
Bends
The fewer bends your new aftermarket exhaust has the better, but you shouldn't straight-pipe it. What you should go for is a mandrel-bent car exhaust which is smooth and has the same diameter from start to finish.
Thickness
Know that high-performance figures require a lot more from your exhaust which is why it's better to go for one made of a thicker material. This makes it more durable but also able to reduce or eliminate exhaust drone depending on how thick it is.
