Exhaustive Series #2: Performance Exhaust Systems - Midwest Aftermarket

Which Complete System is Right for your New Aftermarket Exhaust?

In this article, we will break down the various Exhaust System Types so that you will know which system is best for your vehicle. Now that you know a little about what each part does because you took notes reading the Exhaust 101 article already (didn't ya?), let's see where your exhaust overhaul begins. Should you install a Cat-Back Exhaust System or an Axle-Back? What's the difference between each? Read on to find out.

A Complex Question with Nuanced Answers

The TL;DR Quick Answer

So we, here at Midwest Aftermarket, get asked this question all the time: which complete exhaust system is the best one? And the answer really depends on your vehicle and how you drive it. Thus, the truth is it all depends on you and what you drive. We are going to spend an exhaustive amount of time running through everything from the basics to the most minute bits of minutiae, but if you'd just like the short answer here it goes. If money is no object to you and you are looking for the truly best of the best in performance exhaust systems, your choice should be pretty clear whether you read on or no: get a Complete Aftermarket Exhaust System--a Header-Back Exhaust system--as this will involve an upgrade to every aspect of your exhaust from the Headers all the way back to your Tailpipe, giving you the best possible boost to performance and fuel economy, the note or growl you crave, all while minimizing your backpressure. But that really just covers the obvious, right? What specific system you choose or what Downpipe diameter is really the right size is much more complex than that. It is a no brainer to say replace the whole damn thing also, but what if you can't afford to do it all in one go? Don't worry. We will discuss all your options with handy pictures in this Exhaustive article.

First a Refresher Breakdown

Exhaust System Parts Labeled

Some Additional Piping Not Shown (Also, obviously, not to scale--tee-hee)

Before we look at the various Performance Exhaust System Types, here's a quick closeup.

Header Back Exhaust

Header Back Complete Exhaust System

Perhaps the most complicated part is understanding exactly what parts are replaced in each system. These illustrations should help. Starting with the easiest, in a Header-Back Exhaust System the entire exhaust from Header to Tailpipe is upgraded from start to finish. The ultimate in performance and least restrictive, the header back exhaust is also the most costly and hardest to install simply because you are upgrading every exhaust part.

Turbo Back Exhaust (Turbo Only)

Turbo Back Complete Exhaust System

The second most extensive and most powerful upgrade is the Turbo-Back Exhaust. This system involves replacing everything behind the Turbo, starting with the Downpipe. Those who already have a Turbocharger installed often opt for this upgrade package as it covers just about everything your Header-Back does but means you don't have to remove your Turbo to install. Of course, add in a new Header and you've basically done the whole exhaust too.

Downpipe Back Exhaust

Downpipe Back Complete Exhaust System

This system keeps your stock Downpipe and replaces everything from it on back, including your DPF (if you have a diesel) and your Cat, all the way to your Muffler and Exhaust Tip(s). While both the DPF and Cat are illegal to remove, you can at least upgrade the Cat legally with one that is less restrictive. If you are looking to replace the Cat and don't have a Diesel, this is the system for you. If you are rocking a Diesel, then you'll want to check out a...

DPF Back Exhaust (Diesel Only)

DPF Back (or Filter Back) Complete Exhaust System

If you own a 2007 or newer Diesel, then you've got a DPF (Diesel Particulate Filter). And if you want to upgrade your exhaust but don't want to fuss with that bad boy (whether for legal reasons or just cause it can be a pain in the ass), then a DPF-Back Exhaust will replace everything after that DOC/DPF. Sometimes also called a Filter-Back Exhaust, diesel drivers looking to install an Aftermarket Cat often start here. This upgrade also won't void your warranty.

Cat Back Exhaust

Cat Back Complete Exhaust System

One of the most common exhaust systems, the Cat-Back replaces everything behind the Catalytic Converter (the final one, that is, as you likely have 2 or 3 of these thingies). Many enthusiasts like this system because it leaves the Cat intact, keeping you street legal and keeping your manufacturer warranty while providing some additional power and MPG improvement. Of course, the benefits aren't nearly as great as the comprehensive Header Back.

Axle Back Exhaust

Axle Back Complete Exhaust System

The least expensive and easiest to install, the Axle-Back Exhaust typically just replaces the muffler and your tailpipe, & sometimes also includes a mid-pipe as an adapter piece to tie into stock piping. While this type will not give you as big of a performance boost as any of the others, there is still much to gain (& backpressure to lose) in installing a new muffler section, including nice growl. So if you are looking for sound, this is a great first upgrade.  

Vs. Battle: Comparing One to the Others

Want a Comparison Between Each Exhaust System?

Too freakin' bad. We aren't doing it! Well, kinda. I mean, it's already basically been done for ya above. Those systems are listed in descending order from best performance boost & fuel economy improvement to least, which also probably means they are in descending order on cost (starting with the most expensive) and on difficulty (starting with the most time consuming and difficult) to install.Street Legal Exhaust Systems Want the easiest install you can do at home with some performance gain, while adjusting your stock sound to something powerful? Axle Back is great for that. Looking to maximize performance and got the cash to buy and maybe pay someone to install it for you? You got no excuse not to go all out and get a Header Back system. Looking for the best bang for your buck with performance gain and a boost to fuel economy all with that sweet new growl from your tailpipe? Here's where the argument truly takes off. While enthusiasts and experts alike will argue about this for days, likely the sweet spot is somewhere between Downpipe Back and Cat Back. If you want to stay street legal and are looking for max gain on limited dollars, Cat-Back's the answer. Not so concerned about being street legal? Don't have to pass any emissions tests where you live? Guessing you aren't a California state resident then. Just double checking. Finally, is your vehicle a diesel? Do you have or care to keep your warranty? If you answered "no" to all of those questions, (so you mostly drive off-road and don't need to pass any emissions tests, don't have a diesel, and aren't worried about voiding any warranty) then you can get the most for your dollar by going with a Downpipe Back system as this will offer the least amount of restriction for the money, but it involves losing your Cat and maybe your muffler too, so consider long and hard here. I guess the bottom line is even though I've answered this question at least three different ways now, the answer is complicated and really depends on where you live and how you drive. So make sure you check up on the local laws before you order your brand new exhaust system. We wouldn't want you to fail emissions or get a noise pollution ticket. But we do want you to maximize your performance!

Street Legal

As usual, we aren't in the practice of forcing our views upon you all. Its your truck. Do with it what you like, we say. But we also want to make sure you are a properly informed consumer. If you want to make sure to stay street legal and not void any possible warranties, probably the safest bets for you are Cat-Backs and Axle-Backs or make sure you go with a Gibson Performance Exhaust, as every line they carry is Street Legal. And that's whether you are rocking a diesel or not. If you want to purchase a modified catalytic converter that will improve your horsepower and decrease backpressure, we do offer a number of options from Magnaflow. Beyond that, if you choose to go without a Cat or to remove your DPF, you're on your own with all of that as far as consequences are concerned. Consider this a disclaimer and yourself disclaimed.


Now that that's out of the way, let's say you don't need to be street legal because you're just driving your sweet ass truck off road or you're a guy who likes to just buck the system, kinda like some of us; then why didn't you say so in the first place?! If you are looking to remove any Federally mandated pieces of machinery (again, not that we recommend such madness/excitement), you should consider these three options and read up on each carefully: Header-Back, Turbo-Back, and Downpipe-Back. It is possible to find "off-road" versions of a lot of these. You can tell which is which by carefully examining what comes in the kit. Does it not include a catalytic converter? Does it come with a Test Pipe or Cat Delete? This kind of item allows for the removal of a Cat from your exhaust. Does the kit suspiciously not include a place to connect into your DPF or Cat? We didn't tell you to install it that way, but what you do once you have the equipment in hand is really beyond us. The final big clue that you're browsing these kinds of "off-road" kits is if it is illegal to sell or ship in/to the state of California. There's your red flag. Again, make sure you educate yourself on all local and Federal laws before going this route. We understand your right to Freedom, but that doesn't mean local emissions or law enforcement officers will understand.

Trouble Finding a Specific Style Exhaust System

When in doubt, if you are having trouble locating a specific type of exhaust system for your vehicle, reach out to us. Give us a call and see if we can help. Occasionally there is a case made for not making a Header-Back system, though, for instance, if the stock manifolds are really solid. Some manufacturers might not make a Turbo-Back for a truck that has a really excellent and wide downpipe already equipped stock. So we do occasionally find ourselves in these situations. However, still if you truly want max horsepower/performance unless that stock downpipe is the right diameter and mandrel bent, then you should still probably upgrade that puppy. In this case, you may have to order both a kit and a single extra item or two. In my example, say you can only find a Downpipe Back exhaust kit, you may also be able to order an Aftermarket Downpipe to go along with it, and voila! You basically converted a Downpipe Back Exhaust Kit to a Turbo-Back one. You'll be an exhaust master in no time. But until you get it all figured out, we'll be waiting by the phones to help out. 

Also, our final article, the trinity of the Exhaustive Series is on the way: Ex. Config. & Mats

Gibson Dual Exhaust

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