Catback Exhaust vs Axleback Exhaust – What’s the difference? - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

phenom86 · 07-26-2012, 04:40 PM

Just for reference, specially to the ones who just got bit by the modding bug. Courtesy of APTUNED.com

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.

http://www.aptuned.com/blog/catback-...ifference.html

OrbitalEllipses · 07-26-2012, 05:01 PM

Quote:

Originally Posted by phenom86

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.

Might want to fix the bold portion.

xwd · 07-26-2012, 06:03 PM

It will be interesting when dyno numbers come out for more catback exhausts.

Nameless said they didn't see any gain with replacing the stock midpipe and with a resonator it ended up weighing more than the stock midpipe, so they don't even bother selling a catback version of their exhaust.

However Perrin was able to get like 7WHP more replacing the midpipe versus just replacing the muffler section with a straight pipe... Their prototype catback also didn't really weigh any less than the stock exhaust with the resonator, without I think it saved like 8lbs.

Acc · 07-26-2012, 06:34 PM

My theory is that catback alone there wont be significant gains in power until the entire exhaust system is done. Same issue with the 2.5RS impreza's(98-01) Their issue was that the exhaust outlet was so small it didnt matter what sort of exhaust you had on it until you changed the outlet. Just choose what sort of sound you wanted.

drifter · 07-26-2012, 08:08 PM

I don't want my car to sound faster than it really is. I will wait for some California friendly exhaust system that will increase performance. If not, I'm staying stock.

Pdub86 · 07-27-2012, 10:32 PM

Thanks for all this. It def explained alot and will help me in the future

mike2100 · 07-27-2012, 10:38 PM

Quote:

Originally Posted by phenom86

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.

seriously?

dabocx · 07-27-2012, 11:05 PM

I wonder if the midpipe even makes power, i have a axleback already so im wondering if its worth getting a midpipe made.

xwd · 07-28-2012, 08:30 AM

Quote:

Originally Posted by dabocx

I wonder if the midpipe even makes power, i have a axleback already so im wondering if its worth getting a midpipe made.

I think it will be tough to ever tell. Perrin is te only company I've seen results from which say replacing the stock mid pipe results in more power. Most of the other vendors replacing it are doing it so they can change how the muffler attaches and so they can market a true catback exhaust.

Like I said in my earlier post when I talked to Nameless they said they aren't making one since it didn't add power and would just end up making things more expensive.

BAE · 07-28-2012, 08:39 AM

I am interested in which power gains you could get with headers alone compared to a catback system. I need to keep the cat or get a more open sportscat that can still meet the emission requirements,

Opposed · 07-28-2012, 09:08 AM

Quote:

Originally Posted by BAE

I am interested in which power gains you could get with headers alone compared to a catback system. I need to keep the cat or get a more open sportscat that can still meet the emission requirements,

Look up Lachute Performance. They have dyno's of their headers only on stock exhaust and it did 14whp and 10wtq gain.

07-26-2012, 04:40 PM	#1
phenom86 Senior Member Join Date: Jun 2012 Drives: Scion FRS Asphalt Location: Bay Area Posts: 307 Thanks: 39 Thanked 150 Times in 71 Posts Mentioned: 2 Post(s) Tagged: 1 Thread(s)	Catback Exhaust vs Axleback Exhaust – What’s the difference? Just for reference, specially to the ones who just got bit by the modding bug. Courtesy of APTUNED.com 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. http://www.aptuned.com/blog/catback-...ifference.html Last edited by phenom86; 07-26-2012 at 05:40 PM.

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07-26-2012, 06:03 PM	#3
xwd Senior Member Join Date: Feb 2012 Drives: 2013 DGM Subaru BRZ (Subie #9) Location: ATL, US Posts: 2,667 Thanks: 123 Thanked 860 Times in 552 Posts Mentioned: 32 Post(s) Tagged: 0 Thread(s)	It will be interesting when dyno numbers come out for more catback exhausts. Nameless said they didn't see any gain with replacing the stock midpipe and with a resonator it ended up weighing more than the stock midpipe, so they don't even bother selling a catback version of their exhaust. However Perrin was able to get like 7WHP more replacing the midpipe versus just replacing the muffler section with a straight pipe... Their prototype catback also didn't really weigh any less than the stock exhaust with the resonator, without I think it saved like 8lbs.

07-26-2012, 06:34 PM	#4
Acc Old Schooler Join Date: May 2012 Drives: GD, GC, NPS50 Location: Bellevue, WA Posts: 47 Thanks: 9 Thanked 6 Times in 6 Posts Mentioned: 1 Post(s) Tagged: 0 Thread(s)	My theory is that catback alone there wont be significant gains in power until the entire exhaust system is done. Same issue with the 2.5RS impreza's(98-01) Their issue was that the exhaust outlet was so small it didnt matter what sort of exhaust you had on it until you changed the outlet. Just choose what sort of sound you wanted.

07-26-2012, 08:08 PM	#5
drifter Senior Member Join Date: Jun 2012 Drives: truck and old car Location: CA Posts: 295 Thanks: 120 Thanked 168 Times in 66 Posts Mentioned: 0 Post(s) Tagged: 0 Thread(s)	I don't want my car to sound faster than it really is. I will wait for some California friendly exhaust system that will increase performance. If not, I'm staying stock.

07-27-2012, 11:05 PM	#8
dabocx Senior Member Join Date: Jan 2012 Drives: Scion FRS Location: United States Posts: 1,267 Thanks: 564 Thanked 261 Times in 191 Posts Mentioned: 9 Post(s) Tagged: 0 Thread(s)	I wonder if the midpipe even makes power, i have a axleback already so im wondering if its worth getting a midpipe made.

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