A Quick Guide to Aftermarket Exhaust Systems

03 07, 2022

It’s no secret that car manufacturers leave a lot of room for improvement when it comes to exhaust systems. First, they spend considerable time in research and development then engineer systems that compromise engine performance to achieve an exhaust tone that appeals to mass markets. Lastly, they manufacture those systems using the cheapest materials and most cost-effective processes. In the end, you get a nondescript vanilla exhaust with a forgettable exhaust tone that will start rusting in three or four years.

And that’s why you are looking at aftermarket exhaust systems.

You want to squeeze out extra horsepower by giving your engine the ability to breathe easier, but most of all, you want a sweet exhaust tone that will be uniquely yours. There are dozens of brands offering thousands of exhaust kits for everything from classics to supercars which means you will probably start your search by entering your make, model, and year, and then look at prices. Cost is important, but it isn’t everything.

Must-Haves for Any Exhaust System

Exhaust systems will have differences depending on what they are focused on, increased power, louder exhaust, or just a cool burble growing into a growl as you add revs. That said, all quality exhaust systems should have a few things in common to ensure quality sound, performance, and long service life.

No Drone Technology

All exhaust systems generate drone. Drone is an annoying monotone that, left untreated, finds its way into the passenger cabin. Most stock systems have some type of technology that dampens drone, but that is not true for aftermarket exhausts. More established brands like AWE, Magnaflow, CORSA, and Flowmaster have developed technology for their resonators that control when and where gas is released, eliminating drone. These units are marked No Drone, and your new system should be sporting that label.

Stainless Steel

Aluminized steel is typically what stock systems are made of. Unfortunately, this metal is highly susceptible to rust and corrosion, a real issue if you live where salt and deicers or salt air is present. Stainless steel resists corrosion, and the best stainless steel grade T304L will easily last the lifetime of your vehicle. It is not uncommon to find systems made of T304L having lifetime warranties. ​​​​​​​


As a rule of thumb, you should never have to cut a stock exhaust to install your aftermarket kit. Solid fitment is a sign of excellent engineering and greatly reduces installation time. Furthermore, if you have to cut a stock exhaust, you will likely be voiding the OEM warranty.


By size, we mean the size of the system’s diameter. To ensure the engine is optimally venting gasses, you need a large enough pipe, and that size is based on horsepower. You can use the old rule of thumb of one inch for every 100 horsepower, or you can consult any online exhaust diameter calculators available.

System Designs

Typically, aftermarket exhausts come in three different designs, header-back, cat-back, and axel-back. The names describe where the aftermarket system connects with the stock part and runs to the exhaust pipe. So, a header-back connects at the header, cat-back at the catalyst, and axel back at the axel.


Because it connects directly to the header, this system is the longest, most complex, and normally most expensive aftermarket design. These systems are for people who want maximum horsepower and a thunderous exhaust. This is accomplished by using large pipes to facilitate flow and often excluding any environmental equipment. In many states, they are not street legal and are more likely found in off-road only vehicles and race cars.


The shortest system, axel-backs, are inexpensive and easy to install. They aren’t going to help horsepower output because they are too short, but they can still impact exhaust tone.


The most popular design for aftermarket exhaust systems, the cat-back, is a compromise between header and axel-back systems. It is long enough to allow increased flow, and because it connects after the catalytic converter, there are no environmental issues. These kits consist of a head pipe, resonator, muffler, and tailpipe. The better ones are made of stainless steel and have lifetime warranties.

So there you have it. A starting point in selecting your new exhaust. But, it is always better to have a friend in the business, and we encourage you to call us, and we will be happy to share our ideas and experiences. So we are looking forward to hearing from you.

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