Aftermarket Exhaust System Buying Guide

This buying guide offers a crash course in aftermarket exhaust systems, helping you hone in on the right upgrade for your ride. Learn about the different types of systems, and how they affect performance and sound. To tackle the technical bits, we turned to Jesse Kramer, VP of marketing at AWE. AWE is a Pennsylvania-based manufacturer of award-winning handcrafted performance exhausts, as well as carbon fiber intakes and performance intercoolers.

Sound, power, flexibility, and ease of installation are all major factors to consider when picking out an exhaust system. While it is certainly an area in which you’re free to have fun and simply express yourself, you still want to be mindful of what the car actually needs – and what fits within your budget.

The only problem is there’s a lot more to sort out than you initially thought. From construction to configuration, the sheer number of options can feel endless. That’s why we put together this handy buying guide. With it, you can brush up on the basics and learn more about what makes each exhaust system unique, setting you up to better choose the right system for your ride.

But first things first: Why upgrade your exhaust system in the first place?

Benefits of a Performance Exhaust

There are many reasons to upgrade an exhaust system. Starting with the most obvious motivator, an aftermarket exhaust system is a great way to personalize any ride. Simply put: pick the system with a sound capable of putting that big stupid grin on your face.

In addition to adding bark, however, a performance exhaust adds bite. Let’s face it: a factory system is on the restrictive side, especially if you’re making more power than stock. Aftermarket exhaust parts offer improved flow, which ultimately makes room for more power-rich air and fuel in the combustion chamber.

And, unless you’re buying a top-of-the-line performance vehicle or something from the more prestigious names in the business, you can bet your bottom those factory exhaust parts are made in the cheapest way possible – or close to it. Moving to aftermarket parts can sets enthusiasts up with better-made and longer-lasting components.

Exhaust System Types

In most cases, the words cat-back will dominate exhaust system search results. However, you’re sure to find header-back or axle-back systems as well. What’s the difference?

Each system installs at a different point in the overall exhaust system. Header-back setups essentially replace the entire system from the headers to the tailpipe. Cat-back systems replace everything from the catalytic converter and back. Axle-back systems? Only what’s behind the axle.

As the longest and most comprehensive setups, header-back systems offer the best performance gains. They are also the most expensive and complicated to install. Additionally, they may delete emissions equipment, which makes them a good fit for off-road or racing use only.

On the other end of the spectrum, axle-back systems are the most affordable and easiest to install. Since they replace the muffler, they still produce nice sound quality. However, they are the shortest systems, thus generally doing the least for performance gains.

Cat-back systems fall right in the middle. They leave emissions equipment intact, but still replace an ample amount of the exhaust system. That means they improve power and performance, but don’t cause any legality headaches. All of that, combined with the middle-of-the-road pricing, is what makes this a go-to option for most applications.

Exhaust System Shopping Tips

Once you narrow down the type of system that best suits your vehicle (and budget), it’s easier to begin shopping around.

So, what features should you be looking for?

“Well, there’s what you want and what you need out of an exhaust system,” says Jesse Kramer VP of marketing at AWE. “What you need are proper guarantees — warranty, fitment, no check-engine-light — as well as performance and preferably, something made in the USA from T304L stainless steel. There’s minimal reason to upgrade an exhaust if it’s going to rust out, or if you’ll have to cut or tweak it to make it fit, or if it doesn’t actually add horsepower and torque.”

“Now, what you want is a better sound.”

No Drone

Since sound quality is a main driving point for most exhaust system shoppers, Kramer says the number one thing to look for are the words: “no drone.”

“Many people want a straight pipe sound (or in our case, a “Track Edition” system), but it’s not for everyone,” he says. “If you’re not the type of person who wants it loud 100% of the time — or you have a significant other who is less mod-friendly than you — drone-canceling technology is something to consider.”

Exhaust drone is essentially a loud, monotone sound that rings through the cabin as you drive. (You can see why you might want to avoid this on a daily driver). Keeping drone at bay is one of the primary reasons to stick with more reputable brands when shopping.

There are a lot of manufacturers who can provide a cheap straight pipe. The question is: Will it last? Or is it going to fall off? Will it pass inspection? Does it sound like junk? “There’s a lot you won’t get unless you go to a major manufacturer who has put the time, money, and effort into proper research and development,” stresses Kramer.

For shoppers interested in no drone, he advises they look for a system that uses some type of resonation “to evolve the sound into something that is a bit more tolerable for day-to-day use.”

For example, AWE patented its own drone-cancelling technology called 180 Technology. When exhaust gasses flow into an AWE 180 Technology-equipped resonator, they pass through strategically located ports and reflection chambers, which have been specially engineered based on the sound requirements of the vehicle. Controlling these key elements allows AWE acoustic engineers to control when the sound waves exit the chamber. Carefully timing when the sound waves rejoin the main exhaust flow creates a 180-degree out-of-phase sound wave that cancels out problematic frequencies.

Basically, “When you’re driving down the highway, the exhaust system sounds great – whether you’re at full-throttle or cruising,” sums up Kramer.

Other big-name brands invest in no-drone sound quality, as well. CORSA’s Reflective Sound Cancellation (RSC) technology debuted in 1998 on the C5 Corvette and continues to evolve and improve. Magnaflow uses what it calls No Drone Technology (NDT) to maintain a comfortable in-cabin experience, while Flowmaster employs its Delta Flow Technology to banish errant sonic resonances.

What if you have something older? Our advice is to look for systems that use turbo-style mufflers. They offer great sound quality but virtually zero drone, even when attached to a crude, makeshift system. Dynomax, Thrush, and Pypes make some of the best turbo mufflers on the market.

Quality Steel

The second main feature shoppers should look for when buying an exhaust upgrade is the quality of the stainless steel. “And not just any stainless steel,” says Kramer. “You want high-end stainless steel. As far as longevity is concerned – and something that is worth your money – you want T304L.”

In addition to resisting rust (hence the name), stainless steel has superior high temperature characteristics. This makes it an excellent material for headers and exhaust systems. And while stainless steel has a pretty low carbon content overall, ranging from 0.08% to 0.15%, T304L stainless steel has a particularly low carbon content, maxing out at 0.03%.

In science speak, this translates to less carbide precipitation during the welding process. For you and me, that means T304L stainless steel can be used in an “as-welded” state, even in severe corrosive environments. Basically, those weld joints will hold up much better even when Mother Nature does her worst.

Many aftermarket brands use T409 stainless steel, since it is less expensive and easier to manufacture. While still better than mild steel, T409 won’t hold up as well as T304 or T304L – especially if you live in an area that sees harsh winters and heavy road salt.

Proper Fitment

“The third feature is fitment,” Kramer says, noting that trouble-free installations are worth their weight in gold – quite literally. “If you take your exhaust system to a professional for installation, a lot of these guys are paid flat-rate. If someone is only paid 1 hour to put it on the vehicle, but it takes 3 hours to complete because it didn’t fit – they lose money on the job.” Some manufacturers, like AWE, promise a fitment guarantee. This not only makes life easier for professional installers, but also for consumers who can now enjoy a shorter wait time – or even an easier installation if they choose to tackle the job themselves.

“No check-engine light is huge. At AWE, we have a check engine light guarantee. That should be a question shoppers ask during any exhaust purchase: Do I get some kind of guarantee if I throw a check engine light?”

And lastly: Cutting. “Any chance you get, you want to purchase a product that you don’t have to cut the factory system,” says Kramer. “This is important for resale, but also just for installation. Because, if you have to cut the system at some point, that means you might also need to weld it.” Plus, if you lease your ride, then cutting into a factory system isn’t really an option anyway.

To ensure quality fitment, AWE commits to a pretty thorough process that starts with a 3D scan of the vehicle’s undercarriage, passes through CAD developed prototypes and a very important fixturing phase, and eventually lands in quality control’s hands. Learn more about it here.

If off-roading is on the agenda, you’ll want to consider clearance, too. In addition to a road-friendly Tread Edition, AWE offers a crawler-engineered Trail Edition of its Jeep Wrangler Exhaust Suite. Providing best-in-class clearance on even the most aggressive departure angles, this 3” straight-through cat-back configuration features a bespoke mid pipe resonator, and ends right after the rear axle, tucked up well out of the way of danger.

Helpful Terms

You’re essentially a pro after Kramer’s goldmine of input. However, it’s helpful to understand some of the key terms that will be displayed in every exhaust system’s product description. Knowing them will help you pin down the perfect system.

Pipe Diameter

We’ve all got that buddy with a 4-inch exhaust on his truck that he claims is the cat’s meow. What he means is that the piping used for the exhaust system measures 4-inches in diameter. Wider pipes make more room for flow, which can improve power. Don’t go too wide though, or you’ll kill that precious back-pressure that helps engine performance. The key is to pick a pipe diameter that best matches engine power output and pipe configuration.

Configuration

Single, single to dual, true dual, and dual rear exit, are all terms that define the configuration of the exhaust pipes, which goes hand-in hand with pipe diameter. As a rule of thumb, any system with a single pipe will need a larger diameter than a dual system to perform optimally.

Single exhaust systems feature a single pipe that runs from the manifolds to the rear of the vehicle. Single to dual split the factory’s single exhaust into two pipes, but leave the factory piping that joins behind the manifolds intact. True duals feature two separate pipes that run the length of the vehicle. Dual exits are essentially a single to dual system, only with the split starting much further back.

Material

Exhaust systems can be made of a few different materials. For the most part, you can break those materials into two different categories: aluminized steel and stainless steel. Aluminized steel is what your vehicle has to work with from the factory. Stainless steel may be a little more expensive, but it is more resistant to corrosion and can potentially last the lifetime of your vehicle. As Kramer says, T-304L stainless is the best option to work with.

Sound Level

In a perfect world, manufacturers would all give us sound bites to work with – something AWE actually does very well. (Take a listen, below!) However, it’s still hard to gauge how a system sounds in real life. That’s why some manufacturers use number scales or verbal descriptors to give us an idea of the sound quality. Do yourself a favor and listen to sound bites or YouTube videos featuring the system or mufflers from a system, and read the reviews for added context.

Crossover

H-pipes, X-pipes, what’s the difference? Quite a bit. Not all systems feature crossovers, but you want one if you’ve got a dual exhaust system. These help to equalize exhaust pressure and improve performance. They also happen to have a direct influence on the exhaust note as well. X-pipes tend to create a more high-pitched, euro sound, while h-pipes offer a deeper, more muscular note. Which is preferable is up to you.

Now that you have a good idea of what to look for in an exhaust system, take some time to research the details and compare them to your vehicle’s needs. You’ll be fast on your way to more power, better growl, and a little extra pride in your ride.

Is that all there is to exhaust upgrades, though? No way! There are quite a few modifications you can make to an exhaust system, including headers, mufflers, dumps, and delete kits. Check back soon as we have an easy-to-reference guide on those in the works.