Whether you need an exhaust system because your vehicle's old pipes have rusted through or become damaged, or you simply want a better one to boost engine performance and deliver a more aggressive exhaust note, you've got some great choices to consider. And, as with lots of things in life, it's choices you might not have thought of that turn out to be just what the doctor ordered.
In that spirit, we invite you to spend a few minutes reading this article to learn about and compare "replacement" (OE factory style) exhaust systems and "performance" (aftermarket) exhaust systems. We'll discuss the appeal of each, their general advantages, and factors to consider when shopping for them.
We also look at a few "sample" customers based heavily on actual shoppers of ours, their vehicles, and available choices they would be presented with (see section 9). While we do sell all kinds of individual exhaust system components, we will stick to complete systems for the purposes of this article.
Why Get A Complete Exhaust System?
Trust us when we say if your vehicle needs exhaust work, replacing only one corroded section is faulty economics. Whether it's because you'll spend hours wrestling an old section free from its adjoining pieces, or it's because another section is ready to crumble soon after the initial repair, you'll save both time and money in the long run by doing the repair once - with a complete exhaust system.
And if you're looking for a freer-flowing exhaust system for better sound and power, the only way to purchase such systems is in a complete set.
It's important to note that the term "complete" doesn't mean you need to replace every single bit of the exhaust system back to the engine. In fact, kits are available that offer you a choice of replacing only those components leading back from the rear axle, or from the catalytic converter. Should you decide to go whole-hog and replace everything up to the exhaust manifold, we've got full systems that have you covered as well. We discuss this a little further down in section 6 of this article.
Whether they're OE style or aftermarket performance, exhaust system components must fit together well in order to truly work effectively. Since all pieces of an exhaust kit are engineered together, they'll line up with a seamless, integrated fit that will be easier to install. You won't need to pay an expensive specialist to modify parts that don't mate as they should, and you won't have to deal with engine power losses when ill-fitting pipes create exhaust flow restrictions.
Customers who install a mish-mash of separately-purchased pieces often find that one or more aren't properly sized for their vehicle's power output (or with one another). Unfortunately, the realization that they've inadvertently created a system which disrupts exhaust flow usually comes too late.
What Is A "Replacement" Exhaust System?
In our article Exhaust Kits - The Easy Way To Replace Your Exhaust System, we discuss complete "one & done" exhaust systems that are made to vehicle manufacturer OE (original equipment) specifications. OE style exhaust kits are referred to as "replacement" systems because they're designed to match factory dimensions, shapes, sizes, metal thicknesses, mounting points, and other important criteria.
Because all components are packaged together, the resulting economies of scale result in a lower overall price than could be achieved purchasing all parts separately.
To name a few examples, we've got OE replacement kits for a wide range of makes and models from AP Exhaust, Walker, and Bosal that come with applicable flanges, hangers, and sensor fittings. Once you enter your vehicle's year, make, and model in the Product Options drop down box, you'll see all the parts included in those kits listed individually. Click on just the components you need, and you've created your own exhaust system!
What Is A "Performance" Exhaust System?
Like a replacement factory exhaust system, a performance exhaust system routes the same smog out of your engine, but with wider-diameter pipe sections, less-restrictive mufflers, and an overall layout that's straighter with fewer bends. Depending on the length of system you choose, you may also be replacing your front exhaust section with one that includes wider pipes and a less-restrictive catalytic converter. In many cases, the performance upgrade includes polished mufflers or exhaust tips to provide a splash of eye candy.
The point of all this is to create a freer-flowing path for the exhaust, which reduces overall engine backpressure. When the engine can breathe out easier, it can also breathe in easier to produce additional power and/or achieve better fuel efficiency while cruising. But perhaps the most noticeable result of freer-flowing exhaust systems is a louder, throatier rumble.
A Deeper Rumble
While performance exhaust systems typically have fewer bends and turns in the pipework, the bends they do have are created by a process known as "mandrel bending". This method inserts a series of balls inside a section of pipe before bending is performed on it. Once bent, the diameter of the pipe remains even around curves instead of becoming pinched - producing the desirable throaty sound instead of a pinched, tinny noise.
While most OEM exhaust systems incorporate a resonator that further cancels noise missed by the main muffler, performance systems typically eliminate this part to improve flow, performance, and sound.
Does size matter? When it comes to exhaust systems, numerous studies say larger-diameter pipes do make a difference. Consider the fact that the average exhaust system on most passenger vehicles is rather restrictive. It has to be, in order to provide levels of quiet auto manufacturers believe 99% of their customers demand. Depending on the price point a vehicle will be sold at, automakers may also choose to keep manufacturing costs down by installing OEM systems that meet minimum industry standards.
Since the dawn of hot-rodding, tuners have always followed a rule of thumb. As you tune your motor, make modifications, and add horsepower, you complement those improvements by adding larger exhaust pipes and freer-flowing mufflers to fully maximize those new gains.
On specific product pages for all items we sell, you'll find a description of the amount of extra noise you can expect that exhaust system to produce (mild, moderate, moderate-aggressive, aggressive, etc.), and you'll find diameter measurements for pipes. These details may be right up front in the product descriptions, or they may appear later once make, model, and engine choice have been entered.
For some products, you may see a "Sound" tab to click on - this will play an audio track of that muffler fitted to a pre-determined vehicle. We've also worked hard with some manufacturers to provide a more finely tuned listening experience, which cross-checks the best mufflers for you based on specific vehicle choice and level of sound aggressiveness desired.
X-Pipes And H-Pipes
Regarding performance exhaust systems, we also recommend a look at our article Are X-pipes and H-pipes Better Than Straight Pipes on Dual Exhaust Systems? This delves into how "V" engines benefit from exhaust setups with center sections that create a connection between two pipes that would otherwise be separate. With either an X or H shape to their mid-section, these systems go a step further in decreasing power-reducing backpressure. Among other things, the article also covers how to determine the best mounting spots for your vehicle - and it covers some X-pipe and H-pipe products we feel make excellent choices.
In contrast to H- and X-pipe layouts, "straight through" systems have mufflers of minimal size with fewer baffles. This creates a louder sound and a low amount of restriction. In order to help the engine breathe better, pipes are designed to be as straight as possible on any given vehicle application. Unlike X- and H-pipe setups, dual pipes flow independently of one another at all points.
Customized Ride Heights
If you've modified your 4x4 with a suspension lift or dropped your sled with lowered springs or air suspension setups, we offer specially designed performance exhaust systems with more pipe curvature ahead of the rear axle. This allows a greater degree of up-down wheel travel over the trails, and it allows clearance for low riding on reduced-height springs.
For example, Magnaflow's Off-Road Pro Series system is for American & Japanese trucks, and aFe's Mach Force XP Exhaust System specializes in systems for American, German, and Japanese performance cars.
You Can Choose Exactly How Much Of The Exhaust System You Want To Replace
In addition to other exhaust system classifications, there are additional categories of exhaust systems named for how far they extend up to the front of the vehicle. Any of these lengths are good choices for those who prefer to work on their own vehicle because they include clamps and mandrel bent piping to ensure even diameter and easy flow through all curves.
An "axle-back" system includes a rear muffler(s), and related pipework for it that starts at about the rear axle line of the vehicle. This is a best-cost way to replace a rotted rear muffler if that's your only exhaust problem.
"Cat-back" refers to an exhaust system that comes with all pipework and a muffler(s) that replaces everything starting just behind the catalytic converter. Cat-back systems are the most commonly chosen aftermarket exhaust system because they provide solid performance and sound gains without the great expense of purchasing a new catalytic converter.
However, if you're having issues with your existing catalytic converter that require it to be replaced, consider a full-length "header-back" exhaust system. These run all the way up to the exhaust manifold (a.k.a. header), and include everything a cat-back system does - plus a catalytic converter.
In cases where an engine is turbocharged, kits will include pipe sections that bolt onto the turbo unit instead of the exhaust manifold. With a header-back exhaust system, you'll really benefit if you're upgrading to a low-restriction performance system made of stainless steel or something lighter.
Metals That Exhaust System Components Are Made Of
When it comes to corrosion resistance, stainless steel is a good long-term investment. Because stainless steel exhaust components won't rust, they'll maintain their integrity for as long as you choose to leave them on the vehicle.
We'll note that because exhaust manifolds/headers are bolted directly to the engine block, stainless steel ones can sometimes turn blue right around those attachment points if subject to prolonged heat exposure. For engines that will be run at high rpms and high temperatures for sustained periods of time, stainless steel construction with a ceramic coating is recommended.
Often found in jet engines and aeronautic parts, titanium is both lighter and stronger than stainless steel while being equally as resistant to corrosion. Additionally, titanium can maintain its integrity at extremely high temperatures. As you might imagine, a metal with all these characteristics is a natural fit for high-performance racing applications - making it more desirable because it meets grueling demands when other metals can't.
Because titanium is a less common metal, it's naturally more expensive. And when advanced and sophisticated stamping methods are applied to it to make the kind of exhaust components suited for racing, the overall cost is naturally going to be higher than stainless steel, and more expensive than most OEM metals.
If you enjoy spirited street driving but don't compete where every fraction of a second counts, titanium may not be worth the extra cost to you personally. But if your vehicle does happen to have a roll cage in it, the higher upfront price of titanium can pay excellent dividends at the track.
Stock Exhaust Systems / Carbon Steel
Automakers commonly install exhaust systems made of traditional "carbon" steel at the factory. This is actually an alloy blend that includes nickel, copper, manganese, chromium, and other metals that improve overall corrosion resistance. While durable, carbon steel will rust through eventually, because it does not have the corrosion resistance of stainless steel or titanium.
That said, automakers often equip middle- and upper-level models with stainless steel exhaust systems at the factory.
This is traditional "carbon" steel (not stainless) that's been fully coated on all sides with aluminum-silicon alloy. The process produces a strong metallurgical bond between the two metals which gives traditional steel better corrosion resistance. The underlying steel provides higher strength and rigidity than would be possible with all-aluminum construction, and the aluminum coating allows the whole system to reflect heat away more effectively.
However, while the aluminum coating keeps pit corrosion from occurring in winter climates, aluminized steel can corrode if the aluminum layer is scraped or chipped away by rock hits, scrapes, or other impacts.
"CARB-Compliant" And "EPA-Compliant" Designations
For both replacement and performance type exhaust systems, you may see fitment notes such as the one above regarding a product's "EPA compliant" or "CARB compliant" status. "EPA compliant" components meet federal emissions standards set by the United States Environmental Protection Agency. These will get you through emissions tests in all states except those following more stringent standards set by the California Air Resources Board (CARB).
If you're not sure which set of emissions regulations your state follows, contact the state motor vehicles division to find out. If you live in a CARB-following state, you'll need to select exhaust components that are "CARB compliant".
Containing a variety of sought-after models, Subaru's Impreza 4-cylinder engine lineup ranges from a 148-horsepower 2.0-liter on base models to turbocharged engines of 268-hp (2.0-liter) or 305-hp (2.5 liter) on the WRX. First, we'll look at two neighbors that are looking for exhaust systems for extremely different versions of the 2015 Subaru Impreza.
2015 Impreza WRX
After years of wanting one, Jeff purchased a 2015 WRX 2.0 - Subaru's high-performance version of the Impreza sedan and wagon. With all-wheel-drive, powerful brakes, a capable suspension, and strong turbo power, the WRX truly is a pocket rocket for all seasons. In Jeff's mind, the only thing lacking in his WRX was the 37 extra horsepower found on more expensive WRX STi versions.
To shrink this horsepower gap, Jeff looked at performance exhaust systems with a freer-flowing nature that unlocked additional engine power. Thanks to check boxes on our website, Jeff was able to narrow down his product search to exhaust systems that were a close match for what he wanted in a number of ways.
For example, custom-designed systems are available in single pipe, split pipe, or split pipe with two exits per side. They're typically made of stainless steel, and some even offer full titanium construction (with or without "neo titanium" blue tips in a few cases). Our computer system will also allow you to search exhaust systems with the level of noise you prefer - "Moderate", or "Aggressive/Loud".
Starting with polished stainless steel systems that represented good value, Jeff looked at the Invidia N1 Cat-Back Exhaust System with Single Rear Exit, Borla S-Type Stainless Steel Cat-Back Exhaust System with Quad Rear Exit, MagnaFlow Competition Series Stainless Steel Exhaust System w/Quad Rear Exit, and Injen Stainless Steel Dual Cat-Back Exhaust System w/Quad Rear Exit among many others.
He considered spending a few extra bucks for a titanium system that weighed less and would easily maintain its dazzling, corrosion-free looks. Jeff's main choices were did he prefer a single exhaust exit (Invidia Full Titanium Cat-Back Exhaust System) or four exits (Invidia Gemini Full Titanium Cat-Back Exhaust System with Quad Rear Exit)?
2015 Impreza Base
After riding in Jeff's WRX, his neighbor Jim was inspired to pick up a 2015 base Impreza wagon that best fit his own needs and budget, equipped with a 5-speed manual. With all-wheel-drive, a horizontally opposed engine, and overhead camshafts, even the base model is an all-weather driver's car - a canvas that can easily be customized and improved.
After swerving to avoid a minor accident, Jim ran up on a curb and damaged virtually the entire length of his factory exhaust system. When visiting our website and looking at complete exhaust system choices for his Impreza, Jim realized he could either keep things stock or go for something a little more exciting.
Choosing the "Direct Fit" checkbox, Jim is assured all further choices he sees will be a vehicle-specific, perfect fit. These typically will be offered only in traditional carbon steel to keep costs contained. Today's carbon steel is more resistant to corrosion than its counterparts from decades ago were, so systems made from it now offer great, long-lasting value.
Selecting the "Universal Fit" check box will bring up any systems we carry that may need fitment work because they're designed for multiple vehicles. In the Replacement Exhaust category, we usually don't stock too many.
For a relatively low cost, there's the Walker Replacement Exhaust Kit. This is a good example of a no-frills replacement system at a good value that will maintain factory levels of noise and performance.
For a little more, he also has the option of upgrading to performance polished stainless steel systems with freer exhaust flow. Because they're less restrictive, engine power increases slightly and the exhaust note is louder than stock. For example, there's the Borla S-Type Stainless Steel Axle Back Exhaust System with Single Exit and the HKS Legamax Premium Series Stainless Steel Axle Back Exhaust System with Split Rear Exit.
2014 Chevy Silverado
Chuck bought a 2014 Chevy Silverado 2500 crew cab pickup for his contracting business, which takes him to some rough unpaved areas. In his own mind, Chuck already justified spending money on a lift kit and off-road tires for the truck because the extra protection they afforded him on job sites comes in very handy. Now, he realizes he's got holes in his exhaust system because of rock damage and corrosion. This explains the extra exhaust smell he's noticed while sitting at red lights.
Upon coming to grips with the fact that he needs to spend unexpected money on the truck for a new exhaust system, the question Chuck faces is whether to buy the performance system with a throaty roar he's always wished for, or purchase a less-expensive OEM-style one and reinvest moneys saved back into his business.
When it comes to OEM style exhaust systems, Chuck would be well-served with the Walker Replacement Exhaust Kit. Made of durable carbon steel, this system features components that match the OEM metal thickness, shapes, dimensions, mounting points, and pipe diameters. Other factory style replacement kits for different models include the Bosal Replacement Exhaust Kit and the AP Exhaust Replacement Exhaust Kit.
Should Chuck decide life is too short not to purchase a sweet performance exhaust system, he'll have an easier time deciding on a specific one thanks to check boxes that allow him to customize his product search. For example, he can choose exact length, number of pipes at the end, exhaust sound preference, various diameters, and tip finishes. Selecting the check box for "moderate" exhaust sound, Chuck was presented with some choices for his truck.
If it was equipped with a diesel engine, MagnaFlow's Black Series Stainless Steel Exhaust System (for diesels only) creates great looks with a black finish over stainless steel. It has no catalytic converter, and is designed to extend all the way to the diesel particulate filter (DPF). If a louder, more aggressive exhaust note was preferred, the aFe Large Bore HD Exhaust System (stainless steel) is an example of what's available for diesel models.
We know that this article contains a lot of information to digest, that's why we have specialists available seven days a week to help with any questions you may have. And don't forget to put your vehicle's year, make, and model in our "Select Vehicle" box to narrow your search to products applicable to your vehicle. Once you get a new exhaust system installed, you'll truly appreciate the peace and quiet you'll gain. Or, you'll enjoy the new sounds and rumbles you weren't used to. The choice is yours!