Options for exhaust. Just need opinions.

I have an 88 MJ, 4.0, auto. My current setup is stock pipe from the manifold to the cat, stock cat, 2.5'' pipe and a flowmaster 40 series. This isn't throaty enough for me. I think having so much pipe after the muffler is making it alot quieter. I do like the fact that it kinda "burbles" (dunno how else to describe it) at idle, and it gets kinda throaty on acceleration. What I don't like is that most of what you hear, is engine noise.

What are my options? I looked at borla stuff, no way in hell am i paying 205 bucks for a muffler. Flowmasters and magnaflows are cheaper. I know the 40 series delta flow is supposed to be pretty loud, but they're pretty expencive too.

I've been thinking straight pipe lately. just cut my muffler out, weld in a piece of 2.5'' that i have in the garage. I straight piped my last XJ, and didn't like it. It sounded like a tractor, albeit that it was a 2.5L 4 banger. I have a 1971 ford f100 that i ran straight headers on, and that was just too loud. I'm kinda iffy about straight piping my MJ.


Well, seeing as how I've written a book, I guess I need some opinions. I want it loud. I want it to be noticeable, so you can hear me a block away or so. But I don't want it to be so loud that I never want to romp on it cause it gives me a headache. I don't want alot of resonation, either. What do ya'll think?

I have heard a cherry bomb is pretty loud but still tolerable. I have no experience with one though, I just got a 40 to put on my XJ.

leave the cat(replace if needed), throw a glasspack on, and cut it right after the glasspack, sounds mean cut off pre-axle, but only mj's can get away with it without fumes.

its cheap, sounds good, and its not being a redneck without a cat...

i have a glasspack on my xj with a full tailpipe, it sounds mean, but a friends mj has straight exit right outta the glasspack (with a 4" straight tip), and it echos in the bed, it sounds real nice...

'90 xj 231 ax-15 4.0, i'm running hollowed cat with my muffler replaced with a resonator from a magnaflow exhaust system for a 2004 GTI VR6 LOL it sounds great and I just had it laying around ... now my buddy is running my factory GTI mid muffler as his muffler on a 95 4.0 which also sounds excellant

I went from a flowmaster to a cherry bomb glasspack the cherry bomb is the way to go. louder then the flowmaster but still sounds good and the bonus they are cheap. Also make sure you run the pipe out the back or you will get some nasty headaches from the fumes. Good luck

Well it looks like i had a FM 50 instead of the FM 40 I thought i had. I straight piped it anyways, its louder than hell, raspy, burbley, and I love it. I'm gonna keep it this way till i get tired of it. I can drive with the windows up and I get almost no in-cab noise.

put on a glasspack and say goodbye to low end touque

The 50 is way quieter than the 40 and that right there makes all the difference. For the burbles... just take an angle grinder to the tip. Cut a 45 degree angle off starting from the center of the pipe tip and work towards the outside. Look at a 90's Chevy truck tailpipe for reference. Mine sounded funny until I hacked a piece of my tailpipe off.

I found a picture that is close to what I'm trying to talk about:

http://cache.jalopnik.com/assets/resources/2008/05/tailpipe.jpg

I have a Magnaflow on mine, but it's probably too quiet for what you're looking for. Myself, though, I like it. Nice sound, but not annoyingly loud on the freeway.

+1 for a magnaflow. My personal experience with a 2.8 vw 4.3 chevy and 3.2 isuzu sounds great on V6's.

I straight piped mine and yea it does kinda sound like a tractor, but hey what's wrong with a tractor lol.

i have a 2 piece header going down to dual 2 inch cross over in the middle then dual 2.5" exit.

so in other words true duals.

sounds amazing

Spintech. Nuff Said.

88manche said:

Well it looks like i had a FM 50 instead of the FM 40 I thought i had. I straight piped it anyways, its louder than hell, raspy, burbley, and I love it. I'm gonna keep it this way till i get tired of it. I can drive with the windows up and I get almost no in-cab noise.

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Be careful, during the summer, some places require a sprak arresting muffler.

If you straight pipe it all the way back, it should not be too loud. Even if you pipe it and dump around the axle it should still not be too loud. I would recommend just getting a 12-14" magnaflow/bullet performance muffler in place if what you got, and figure out how far back you want to go with it. Or, if you want, you can pick up a Flowtech Warlok muller. It comes with a removable "flow intensifier" So you can run straight out from it.

I actually engineer exhaust systems for a living, and there are a few things you can do to make it sound nice. Alot of engines actually sound very nice with just a catlytic converter and no muffler, as the converter does a decent job of cutting the waves on most vehicles. If you live in a state like here in Michigan, and you can get away without a converter, go for it. There are a couple things to look out for though:

Like another member said, the length and shape of the tailpipe actually makes a huge difference that most people don't realize, as this is where the sounds waves meet your ears! Experiment with the angle and shape of the outlet to get a sound that you like. On some cars it makes a big difference in sound, others not. It's kind of a guessing game based on the geometry of the system before the tailpipe.

Try to avoid long straight sections of pipe, as these will create standing waves, which is the annoying resonance you hear at a certain rpm on some cars. If you find that you get this, you can usually stop it by putting in a muffler at the mid point in the straight section, or at the 1/4 or 3/4 points if this doesn't help. Just remember that this applies to taking out the converter, as this can create another standing wave location. And the muffler doesn't even need to be a true muffler to cure this, even a hollowed out "cherry bomb" can work as a resonator of sorts. Again, it's kind of a guessing game, I've seen some systems that can have mile long sections of straight pipe with no bad resonance, and other can get it with a 2 foot long piece!

Hope my .02 dollars might have helped!

my GF got me the super 40 or whatever it is.
the diamond plate one...
it's pretty loud, like too loud.
I'm not gonna remove it but I wish I had a slightly smaller one...

xcm said:

leave the cat(replace if needed), throw a glasspack on, and cut it right after the glasspack, sounds mean cut off pre-axle, but only mj's can get away with it without fumes.

its cheap, sounds good, and its not being a redneck without a cat...

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i have mine cut off right after the glasspack and have been running it for about 6 months with no fume complaints.

ROBZ95Xj said:

put on a glasspack and say goodbye to low end touque

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i still have plenty of low end torque on mine. stock 3.55's with 32's. even with 33" boggers it would crawl through just about anything and would pull like hell when i had to power out of pits

ROBZ95Xj said:

put on a glasspack and say goodbye to low end touque

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I actually noticed a gain in low end over having a chamber muffler. Hell I even noticed a gain in low end when my exhaust got ripped off right before the cat. Common thinking would say lose backpressure= loose low end, but not my experience at all.