APtuned Blog

12May/125

Catback Exhaust vs Axleback Exhaust – What’s the difference?

When looking for performance parts for your car or truck, it's often times difficult to understand what the difference is between certain parts if you are new to the performance and aftermarket scene or simply haven't heard of what the difference would be between two parts that might not have interested you in the past. A common question we get is "What is the difference between a catback exhaust and an axleback exhaust and which one is better?".

What is a catback exhaust?
A catback exhaust is an exhaust that begins at the end of your catalytic converter and goes all the way back to your rear bumper. For short, people call a catalytic converter a "cat", and this exhaust is a cat-back, so it goes from the cat to the back of your car or truck. A full catback exhaust includes the intermediate pipe, muffler and exhaust tip. For some cars or trucks that have extremely restrictive exhausts, it would make sense to replace to get a performance catback exhaust to free up your exhaust, so your engine can breathe better and make more power. Not all cars or trucks need a catback exhaust, and we'll explain more below.

What is an axleback exhaust
A catback exhaust starts from the catalytic converter back, but an axleback starts from the area of the rear axles back to your rear bumper. It doesn't include an intermediate pipe, this is why the axleback exhaust is typically more expensive. For front wheel drive cars that do not have a rear axle, it starts near the area where your axles would be, which is right in between your rear tires. For cars that are rear wheel drive, this would be the area where your rear axles are. Both a catback and an axleback include the muffler with tip.

So which do you recommend? A full catback or an axleback?
Usually a catback creates more power over an axleback. This is because you are replacing more restrictive exhaust with a catback than you are with an axleback. For some cars, there is only an option of an axleback. This isn't necessarily a bad thing. If the only option is an axleback, it will save you money over a catback, plus some cars have pretty decent size piping from the factory so there is no benefit to replacing more of your exhaust than is necessary. If your exhaust is already good flowing for your performance needs from the factory (minus adding a power adder such as nitrous, a turbo or a supercharger), then an axleback would be perfect. It would give you the sound you like plus remove the restrictive factory muffler. If your car has the option for both, we would recommend for you to plan if you will be adding more power adders such as a short ram intake or cold air intake, then we would go for the catback exhaust. If you are just looking to upgrade your ugly factory muffler with something sporty and that sounds good and save a few hundred bucks, you can't go wrong with an axleback. On the other hand, some aftermarket companies only produce an axleback for a car, because they believe the extra cost is worth the added power.

If you care about noise, an axleback is usually quieter as well, since you keep your factory resonator (which is located on the mid pipe or intermediate pipe) if your car has one stock.

What's the difference between mandrel bent exhaust and press bent exhaust?
A mandrel bent exhaust means the bends in the exhaust are smooth and do not neck down. A press bent exhaust has "dents" in the bends which causes a disruption in flow and isn't good for producing power. Many older cars have press bent exhausts, so a performance unit would give you a good boost in power.

What size piping is good for an exhaust?
This really depends on what you are going after, and what size your factory exhaust is. For example, for a turbo car, we recommend a 3" exhaust for max flow. For a non turbo, we would recommend a 2.3" to 2.5" exhaust depending on the size of your engine. For max flow, we would go with a 2.5" exhaust, but bigger if you are going to have a fully built engine, or some engine work such as porting or cams. Typically aftermarket companies take your stock engine size into account and create an exhaust size that will work best for you.

I put on an aftermarket exhaust and now my car feels slower, what's going on?
Depending on the car or truck, some people feel as though their car is slower or has lost power. Generally this is not the case. For an otherwise stock or slightly modified car, it might feel like some power has been lost because your power curve has been adjusted upwards. If you still have a stock catalytic converter, you won't notice it as much, but since your power curve has changed, you will need to get used to the new power delivery. After a few days, you will begin to appreciate the added power.

Do I need to get my car tuned after getting an exhaust installed?
Usually no, but if you have a turbo or supercharged car, then yes. On an otherwise stock or slightly modified car, the exhaust will not throw off the air/fuel mixture enough that the factory computer can't compensate. As you drive your car, the ECU will adjust for the added exhaust flow, and your car will run smooth and you will have full power benefits.

Why do people have angled exhausts? Is this just a style trend?
The angled exhaust trend started in Japan with drifters, but has caught on everywhere. The reason the exhaust is angled is to keep the exhaust piping as straight as possible. The less amount of bends, the more power you will make due to less restriction. The goal is to give your exhaust an easy way to escape.

My car has a dual exhaust. Do aftermarket exhausts also have dual mufflers?
If your car has a stock dual exhaust setup, most aftermarket exhausts will also be dual. However, some specifically say single muffler and the reason is to keep weight down. Since a dual setup requires two mufflers and an extra pipe, it's also less expensive to go with a single setup. This is a personal choice, and usually more hardcore people go for the single setup when their cars are dual stock to save as much weight as possible.

Do these come with silencers?
Depending on the design and size of the mufflers, not all exhausts come with silencers. A silencer hurts power by adding in a big restriction, and most aftermarket exhaust companies would rather you run it without a silencer.

Why are some exhausts so loud and some are so quiet?
Loud usually means power! If the exhaust is quiet, it's usually a muffler that is restrictive. A loud exhaust means it's very low restriction and the muffler doesn't do much to "muffle" the exhaust. This isn't always the case, some quiet exhausts produce as much power as loud exhausts, but every case is different. Generally speaking, a louder exhaust simply gives you more exhaust flow.

How can I keep my exhaust from being raspy or sound like a "bumble bee"
Usually an exhaust can get rid of it's "edge" or raspy sound with a resonator. A resonator is designed to ease the exhaust flow, adding a little bit of restriction, but many times removing the rasp or "bumble bee" sound many exhausts experience. Usually quieter exhausts do not have this problem since they have a resonator built in.

Which exhausts do you recommend?
Here are a few of the ones we recommend:

APEXi
COBB Tuning
DNA Motoring
GReddy
HKS
Invidia
Magnaflow
Megan Racing Axle Back
Megan Racing Drift Spec
Tanabe
Vibrant
Yonaka

We hope that you find our exhaust information useful. If you have any questions or anything to add, please do not hesitate to add your comments below. Enjoy!


Comments (5) Trackbacks (0)
  1. I have a 2013 Elantra Sedan and I want to know if dual exhaust or single exhaust is the way to go in terms of budget. I want a low deep sounding exhaust that’s street legal and won’t have a huge affect on gas mileage. I’m not looking to go on a race track or anything, it’s mainly for cosmetics. Do you have any recommendations? I’m new to this so your help is greatly appreciated? Thanks in advance.

  2. I have a c5 corvette and i switch my exhaust to the slp loudmouth and i feel like it has lost horse power .. Wats going on ?

  3. I have a 2012 Mitsubishi Lancer GT and was curious I which exhaust would work best and which brand would someone recommend?

  4. My 5.7L Charger came with 2 1/2″ exhaust pipes and exhaust crossover pipe, followed by mufflers, Tail pipes and resonators. The recommended catback system are also 2 1/2″. Is the after market exhaust pipes and cross overs that much more efficient?

  5. i have a bh5 legacy twin turbo i removed the axle back exhaust and i have weld a straight pipe..can this affect my engine..? Pliz help


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