exhaust: glasspack vs. muffler
CF Veteran
Joined: Aug 2010
Posts: 2,038
Likes: 4
From: DIRTY SOUTH
Year: 1991
Model: Cherokee
Engine: 4.0 ho
I understand the less pipe(saves you some money), and not to be an *** just curious, does it really make that big of a difference in restriction going the few bends over the axles and out? i mean i understand that thinking on a drag car cuz they can use every single bit of power there is to get, but on a jeep? I have the turndown in front of the axle now and i just cant stand the fumes when i let it idle, especially with my kid on board. Not trying to start any arguements just my opinion.
Junior Member
Joined: Jan 2011
Posts: 89
Likes: 0
From: Turlock
Model: Cherokee
Wow there's a lot of differing opinions and information on this topic so I might as well throw in my 2 cents :P
To make a true noticeable difference in your exhaust flow you would need to run straight pipes by taking out the cat and muffler, and then you would still have to change to high flow headers to cause a real noticeable difference in mid to high-end range horsepower since that's when the engine needs that flow to push exhaust (and provide better gas mileage) This would also take away a decent amount of low-end torque due to the release of back-pressure in the exhaust system. I don't know all the physics behind why it does this, but I have been told that the best way to attain/keep torque is to keep a consistent pressure between your intake and exhaust manifolds. This keeps your engine response quick and the valves/pistons/engine inlets and outlets running most efficient. Thus the reason to why the REAL pros (engine's and manufacturer's designers) make it that way.
A glass pack does have a straight-through design, but so does borla, magnaflow, and pretty much every other performance muffler except for flowmaster and alikes which throw in the chamber system that sound enthusiasts like to have (I'm a huge fan of the super-40 series, its not too loud except for when you wanna stomp on it, which then wakes up the engine, and ur neighbors, with an exhilarating roar)
Pipe size in these engines don't make a difference in anything except for louder sound and bragging rights. Taking pipe back to the rear bumper makes no difference in hp/torque then if you had it turned down after the muffler. It does however change the sound (too loud in my opinion) and you risk getting fume leaks into the cabin.
Exhaust is really a personal preference. It adds personality and performance to your ride but also is an expression of your personality. so I suggest listening to the different styles on you-tube (with a good pair of speakers to reproduce the sound real well) and make a good investment in something you would enjoy for a long time.
My suggestion? take out the cat, throw on a flow-master muffler like a 40 or 50 series that provide a sweet sound and aren't too loud (the straight through mufflers like magnaflow and borla often sound like a ricer unless it's on a V8 ). Then have new pipe ran back to the rear and throw on a nice chrome tip in a good location not to get crimped. Theres your classy stock xj look when you pull up to the trails, but gives real attitude when you put the power to the pedal, but that's just me.
To make a true noticeable difference in your exhaust flow you would need to run straight pipes by taking out the cat and muffler, and then you would still have to change to high flow headers to cause a real noticeable difference in mid to high-end range horsepower since that's when the engine needs that flow to push exhaust (and provide better gas mileage) This would also take away a decent amount of low-end torque due to the release of back-pressure in the exhaust system. I don't know all the physics behind why it does this, but I have been told that the best way to attain/keep torque is to keep a consistent pressure between your intake and exhaust manifolds. This keeps your engine response quick and the valves/pistons/engine inlets and outlets running most efficient. Thus the reason to why the REAL pros (engine's and manufacturer's designers) make it that way.
A glass pack does have a straight-through design, but so does borla, magnaflow, and pretty much every other performance muffler except for flowmaster and alikes which throw in the chamber system that sound enthusiasts like to have (I'm a huge fan of the super-40 series, its not too loud except for when you wanna stomp on it, which then wakes up the engine, and ur neighbors, with an exhilarating roar)
Pipe size in these engines don't make a difference in anything except for louder sound and bragging rights. Taking pipe back to the rear bumper makes no difference in hp/torque then if you had it turned down after the muffler. It does however change the sound (too loud in my opinion) and you risk getting fume leaks into the cabin.
Exhaust is really a personal preference. It adds personality and performance to your ride but also is an expression of your personality. so I suggest listening to the different styles on you-tube (with a good pair of speakers to reproduce the sound real well) and make a good investment in something you would enjoy for a long time.
My suggestion? take out the cat, throw on a flow-master muffler like a 40 or 50 series that provide a sweet sound and aren't too loud (the straight through mufflers like magnaflow and borla often sound like a ricer unless it's on a V8 ). Then have new pipe ran back to the rear and throw on a nice chrome tip in a good location not to get crimped. Theres your classy stock xj look when you pull up to the trails, but gives real attitude when you put the power to the pedal, but that's just me.
Last edited by CenCaliAlum2010; Mar 20, 2011 at 05:57 PM.
CF Veteran
Joined: Aug 2010
Posts: 2,038
Likes: 4
From: DIRTY SOUTH
Year: 1991
Model: Cherokee
Engine: 4.0 ho
Wow there's a lot of differing opinions and information on this topic so I might as well throw in my 2 cents :P
To make a true noticeable difference in back pressure and free flow you would need to run straight pipes by taking out the cat and muffler. Even then you would still have to change to high flow headers to cause a real noticeable difference in mid to high-end range horsepower (and better gas mileage) This would also take away a decent amount of low-end torque due to the release of back-pressure in the exhaust system. I don't know all the physics behind why it does this, but I have been told that the best way to attain/keep torque is to keep a consistent pressure between your intake and exhaust manifolds. This keeps your engine response quick and the valves/pistons/engine inlets and outlets running most efficient. Thus the reason to why the REAL pros (engine's and manufacturer's designers) make it that way.
A glass pack does have a straight-through design, but so does borla, magnaflow, and pretty much every other performance muffler except for flowmaster and alikes which throw in the chamber system that sound enthusiasts like to have (I'm a huge fan of the super-40 series, its not too loud except for when you wanna stomp on it, which then wakes up the engine, and ur neighbors, with an exhilarating roar)
Pipe size in these engines don't make a difference in anything except for louder sound and bragging rights. Taking pipe back to the rear bumper makes no difference in hp/torque then if you had it turned down after the muffler. It does however change the sound (too loud in my opinion) and you risk getting fume leaks into the cabin.
Exhaust is really a personal preference. It adds personality and performance to your ride but also is an expression of your personality. so I suggest listening to the different styles on you-tube (with a good pair of speakers to reproduce the sound real well) and make a good investment in something you would enjoy for a long time.
My suggestion? take out the cat, throw on a flow-master muffler like a 40 or 50 series that provide a sweet sound and aren't too loud (the straight through mufflers like magnaflow and borla often sound like a ricer unless it's on a V8 ). Then have new pipe ran back to the rear and throw on a nice chrome tip in a good location not to get crimped. Theres your classy stock xj look when you pull up to the trails, but gives real attitude when you put the power to the pedal, but that's just me.
To make a true noticeable difference in back pressure and free flow you would need to run straight pipes by taking out the cat and muffler. Even then you would still have to change to high flow headers to cause a real noticeable difference in mid to high-end range horsepower (and better gas mileage) This would also take away a decent amount of low-end torque due to the release of back-pressure in the exhaust system. I don't know all the physics behind why it does this, but I have been told that the best way to attain/keep torque is to keep a consistent pressure between your intake and exhaust manifolds. This keeps your engine response quick and the valves/pistons/engine inlets and outlets running most efficient. Thus the reason to why the REAL pros (engine's and manufacturer's designers) make it that way.
A glass pack does have a straight-through design, but so does borla, magnaflow, and pretty much every other performance muffler except for flowmaster and alikes which throw in the chamber system that sound enthusiasts like to have (I'm a huge fan of the super-40 series, its not too loud except for when you wanna stomp on it, which then wakes up the engine, and ur neighbors, with an exhilarating roar)
Pipe size in these engines don't make a difference in anything except for louder sound and bragging rights. Taking pipe back to the rear bumper makes no difference in hp/torque then if you had it turned down after the muffler. It does however change the sound (too loud in my opinion) and you risk getting fume leaks into the cabin.
Exhaust is really a personal preference. It adds personality and performance to your ride but also is an expression of your personality. so I suggest listening to the different styles on you-tube (with a good pair of speakers to reproduce the sound real well) and make a good investment in something you would enjoy for a long time.
My suggestion? take out the cat, throw on a flow-master muffler like a 40 or 50 series that provide a sweet sound and aren't too loud (the straight through mufflers like magnaflow and borla often sound like a ricer unless it's on a V8 ). Then have new pipe ran back to the rear and throw on a nice chrome tip in a good location not to get crimped. Theres your classy stock xj look when you pull up to the trails, but gives real attitude when you put the power to the pedal, but that's just me.
CF Veteran
Joined: Feb 2011
Posts: 1,838
Likes: 1
From: South Dakota
Year: 1992
Model: Cherokee
Engine: 4.0
i completely understand but im 18 and no kids so i dont have to worry about that,and if i had a kid i would worry a about it a lil bit,but its mainly sounds better wit a turndown pipe,it echoes off the ground,and makes it sound deeper,but since i got a glasspack it wont make munch of a difference from where mines at to the back bumper,but if i had a actual chamber muffler then it might,since the chamber is more restrictive and less pipe after it is more restriction gone than all the way back
CF Veteran
Joined: Aug 2010
Posts: 2,038
Likes: 4
From: DIRTY SOUTH
Year: 1991
Model: Cherokee
Engine: 4.0 ho
Idk what age has do with having a kid, im only 19 and i've got a little guy of my own, cant say it was expected but i love that little boy. But back to the subject, i understand what your saying and never said it didn't sound better, and yeah it will have less restriction if you dont run it out the back, my question is, is it really gonna be THAT noticable or all that effective with that tiny bit of less restriction? If i didn't have my little co-pilot i'd leave my exhaust where it is(befor the axle) and save $80, but i wouldn't be doing it for less restriction, it'd be soly for hearing it better when i throttle out
CF Veteran
Joined: Feb 2011
Posts: 1,838
Likes: 1
From: South Dakota
Year: 1992
Model: Cherokee
Engine: 4.0
Wow there's a lot of differing opinions and information on this topic so I might as well throw in my 2 cents :P
To make a true noticeable difference in your exhaust flow you would need to run straight pipes by taking out the cat and muffler, and then you would still have to change to high flow headers to cause a real noticeable difference in mid to high-end range horsepower since that's when the engine needs that flow to push exhaust (and provide better gas mileage) This would also take away a decent amount of low-end torque due to the release of back-pressure in the exhaust system. I don't know all the physics behind why it does this, but I have been told that the best way to attain/keep torque is to keep a consistent pressure between your intake and exhaust manifolds. This keeps your engine response quick and the valves/pistons/engine inlets and outlets running most efficient. Thus the reason to why the REAL pros (engine's and manufacturer's designers) make it that way.
A glass pack does have a straight-through design, but so does borla, magnaflow, and pretty much every other performance muffler except for flowmaster and alikes which throw in the chamber system that sound enthusiasts like to have (I'm a huge fan of the super-40 series, its not too loud except for when you wanna stomp on it, which then wakes up the engine, and ur neighbors, with an exhilarating roar)
Pipe size in these engines don't make a difference in anything except for louder sound and bragging rights. Taking pipe back to the rear bumper makes no difference in hp/torque then if you had it turned down after the muffler. It does however change the sound (too loud in my opinion) and you risk getting fume leaks into the cabin.
Exhaust is really a personal preference. It adds personality and performance to your ride but also is an expression of your personality. so I suggest listening to the different styles on you-tube (with a good pair of speakers to reproduce the sound real well) and make a good investment in something you would enjoy for a long time.
My suggestion? take out the cat, throw on a flow-master muffler like a 40 or 50 series that provide a sweet sound and aren't too loud (the straight through mufflers like magnaflow and borla often sound like a ricer unless it's on a V8 ). Then have new pipe ran back to the rear and throw on a nice chrome tip in a good location not to get crimped. Theres your classy stock xj look when you pull up to the trails, but gives real attitude when you put the power to the pedal, but that's just me.
To make a true noticeable difference in your exhaust flow you would need to run straight pipes by taking out the cat and muffler, and then you would still have to change to high flow headers to cause a real noticeable difference in mid to high-end range horsepower since that's when the engine needs that flow to push exhaust (and provide better gas mileage) This would also take away a decent amount of low-end torque due to the release of back-pressure in the exhaust system. I don't know all the physics behind why it does this, but I have been told that the best way to attain/keep torque is to keep a consistent pressure between your intake and exhaust manifolds. This keeps your engine response quick and the valves/pistons/engine inlets and outlets running most efficient. Thus the reason to why the REAL pros (engine's and manufacturer's designers) make it that way.
A glass pack does have a straight-through design, but so does borla, magnaflow, and pretty much every other performance muffler except for flowmaster and alikes which throw in the chamber system that sound enthusiasts like to have (I'm a huge fan of the super-40 series, its not too loud except for when you wanna stomp on it, which then wakes up the engine, and ur neighbors, with an exhilarating roar)
Pipe size in these engines don't make a difference in anything except for louder sound and bragging rights. Taking pipe back to the rear bumper makes no difference in hp/torque then if you had it turned down after the muffler. It does however change the sound (too loud in my opinion) and you risk getting fume leaks into the cabin.
Exhaust is really a personal preference. It adds personality and performance to your ride but also is an expression of your personality. so I suggest listening to the different styles on you-tube (with a good pair of speakers to reproduce the sound real well) and make a good investment in something you would enjoy for a long time.
My suggestion? take out the cat, throw on a flow-master muffler like a 40 or 50 series that provide a sweet sound and aren't too loud (the straight through mufflers like magnaflow and borla often sound like a ricer unless it's on a V8 ). Then have new pipe ran back to the rear and throw on a nice chrome tip in a good location not to get crimped. Theres your classy stock xj look when you pull up to the trails, but gives real attitude when you put the power to the pedal, but that's just me.
)
CF Veteran
Joined: Feb 2011
Posts: 1,838
Likes: 1
From: South Dakota
Year: 1992
Model: Cherokee
Engine: 4.0
i have noticed a difference,a lil one but its still a better one,but i also had the stock muffler all the way back then i went to the glasspack and a turndown pipe so theres a decent amount of difference in the restriction between the 2,but there wont be alot of difference between mine now and havin it run back all the way,but mine was mainly for sound a and price
Junior Member
Joined: Jan 2011
Posts: 89
Likes: 0
From: Turlock
Model: Cherokee
Originally Posted by Kyle 4x4 4life
... it will have less restriction if you dont run it out the back, my question is, is it really gonna be THAT noticable or all that effective with that tiny bit of less restriction? If i didn't have my little co-pilot i'd leave my exhaust where it is(befor the axle)...
Last edited by CenCaliAlum2010; Mar 20, 2011 at 06:24 PM.
CF Veteran
Joined: Feb 2011
Posts: 1,838
Likes: 1
From: South Dakota
Year: 1992
Model: Cherokee
Engine: 4.0
You will definitely notice a difference when changing from the stock muffler to anything else. Those stock mufflers are designed for quiet operation and good gas mileage for the average driver, which jeep owners usually are not 8) haha but if you have no pipe after the muffler, adding pipe back to the bumper will make absolutely no noticeable difference in performance. Even throwing it on a dyno will show that there is minimal to no difference from adding a few feet of pipe after the muffler... I believe it is a common misconception that people tie louder sound with more horsepower.
I dont do exhaust thinking im gonna gain a ton of power and make my vehicle a ton faster, i do it to give it a nice tone and turn some heads with the added affect of losing some restriction compared to stock
Junior Member
Joined: Jan 2011
Posts: 89
Likes: 0
From: Turlock
Model: Cherokee
Originally Posted by Kyle 4x4 4life
Well ya i know switching from a stock muffler to a aftermarket one will be noticable, i never said anything like that. I was just talking about the addition of the pipe after the muffler out the back. And trust me there are tons of people in my town who rod their vehicles around with either no muffler or a loud one and think its the fastest thing in town just because its loud I dont do exhaust thinking im gonna gain a ton of power and make my vehicle a ton faster, i do it to give it a nice tone and turn some heads with the added affect of losing some restriction compared to stock
I dont do exhaust thinking im gonna gain a ton of power and make my vehicle a ton faster, i do it to give it a nice tone and turn some heads with the added affect of losing some restriction compared to stock
CF Veteran
Joined: Feb 2011
Posts: 1,838
Likes: 1
From: South Dakota
Year: 1992
Model: Cherokee
Engine: 4.0
My bad I guess I read it wrong heh. You are correct though the mufflers are great for sound and a slight increase in hp. I havnt owned a ride that hasn't had a good sounding exhaust. It just makes driving more fun and enjoyable when you can hear the horses under the hood and can unleash them at any given will. Only problem is that in my experiences I've learned that cops and car thieves in my area also like to pay attention to those cars more...
But back in my younger days...(im 19)lol i had the crazy thought that i had to straight pipe every vehicle so it was as loud as possible, i had on old diesel chevy with 7" stacks that was so loud you couldn't even talk to your passenger in the cab if you where on the throttle at all and suprising enough the cops never bothered me, but i did make sure i just coasted when a cop drove past me
and car thieves in my area are near unheard of, truthfully cant remember that last car theft in my town...there is only like 4,000 people in my town though. But anyways im getting a little bit smarter as i get older and starting to like the nice clean sound that the muffler puts out.
Last edited by Kyle 4x4 4life; Mar 20, 2011 at 08:07 PM.
Seasoned Member
Joined: Dec 2010
Posts: 345
Likes: 1
From: So. California
Year: 1991
Model: Cherokee
Engine: 4.0 HO
Someone may have already mentioned this, but any packed muffler you get "glasspack" or ceramic packed will get louder as it gets older because the packing will eventually burn away.
Junior Member
Joined: Jan 2011
Posts: 89
Likes: 0
From: Turlock
Model: Cherokee
Originally Posted by AMXJ
Someone may have already mentioned this, but any packed muffler you get "glasspack" or ceramic packed will get louder as it gets older because the packing will eventually burn away.
CF Veteran
Joined: Feb 2011
Posts: 1,838
Likes: 1
From: South Dakota
Year: 1992
Model: Cherokee
Engine: 4.0
Someone may have already mentioned this, but any packed muffler you get "glasspack" or ceramic packed will get louder as it gets older because the packing will eventually burn away.
Found this post on another forum pertaining to glass packs and in opinion he has a real good point.
The design technology alone is over 30 years old and I don't even think it was the best available back then. There are a lot of mufflers out there that look, sound and operate a lot better than glasspacks... I kindof think of glasspacks as the "why bother" muffler. I think if you actually tried a set of flowmasters or hookers, you would be surprised by how much better your car sounds and how much more power you make. Newer mufflers like flowmaster are much more professional sounding and give your car some class. They rumble when you're idling, but get pretty loud when you hammer it, that's how (I think) its supposed to be. Who wants to drive around in a car you can't hear yourself think in? I guess I'd just rather people think "man that car sounds mean" than "good God, that thing sounds like crap and is obnoxiously loud!
Just my .02
Thread Starter
Seasoned Member
Joined: Jan 2009
Posts: 443
Likes: 2
From: Prescott, AZ
Year: 1996
Model: Cherokee
Engine: 4.0L
Okay, another question. I just got under my jeep and pulled of the old exhaust system and found that the down pipe actually measures 2.5 inches. I thought I was supposed to use a 2.25 inlet/outlet muffler. What should I do? Use a coupler to convert 2.5 down to 2.25 before the muffler? Get a muffler that is 2.5 inlet and 2.25 outlet? Or just use a 2.5 inlet/outlet muffler? Thanks.
