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Flowmaster 50 on cat-less Renix?

Flowmaster's are some of the worst flowing mufflers. My friend has your exact setup on a HO motor with headers and it sounds like a tractor. i'd go with a dynomax or a gibson or ANYTHING but flowmaster. I gotta say Glasspacks sound great too. been meaning to make a video of my glasspack and headers
 
I have a Borla system on my 87 Renix. Sounds great!! Nice and mellow at idle, it gets kinda loud inside (Keep in mind I have no carpet) about 3000 RPM, but stays nicely tuned outside.

I have heard one with a glasspack, it too sounds pretty good.

BTW Flowmasters sound like crap on a 4.0L
 
I run a glasspack on mine and it was catless when I got it. Sounded good but loud. With a cat it's about perfect. An added benefit is that it's a lot harder to tear off on a rock than a typical muffler. My XJ sees a fair amount of rocks and the glass pack doesn't have a dent in it.
 
Boy, I've never heard anyone saying a Flowmaster sounds like crap!

I thought I'd pony up for Rusty's "performance kit" with a 50 Series Flowmaster and an intake with a 9x6" K&N. $240?
 
wannajeep said:
I run a glasspack on mine and it was catless when I got it. Sounded good but loud. With a cat it's about perfect. An added benefit is that it's a lot harder to tear off on a rock than a typical muffler. My XJ sees a fair amount of rocks and the glass pack doesn't have a dent in it.
Click to expand...

Who makes the glasspack that you have? Is it too loud driving into the neighborhood at 3am?
 
I have a Flowmaster 40 without and pipe behind it(it kept getting tore off.) and IMHO it sounds great, very deep and throaty sound.
 
NXJ said:
I thought I'd pony up for Rusty's "performance kit" with a 50 Series Flowmaster and an intake with a 9x6" K&N. $240?
Click to expand...

I bought the same package except with a 40 Series and the smaller intake. It wasn't worth it in my opinon. The exhaust rubbed and was considerably too short. And the 9x6" is going to be ALOT bigger then you think. You could probably get a Flowmaster mounted up at an exhaust shop for cheaper.
 
What do you mean it was too short? I dunno, but it looked like a nice, smooth mandrel bent piece in the pics? As far as the filter; the bigger the better? :D
 
I got the Rusty's performance kit on my '99. The 50 series delta flow sounds nice at low rpm, but idle and high rpm don't sound much different than stock to me. Not sure what difference not having a cat will make on the sound since it really doesn't cause much restriction as is. As for the filter, the smaller one is fine and leaves you lots of room to mount stuff under the hood. Some people seem to hate the K&N's and complain of particulates in thier TB and intake, but I have not had a problem with mine. Just FOLLOW THE DIRECTIONS for cleaning (as in wash and let fully dry, then lightly oil and let sit for the full 24hrs. I recently had my TB off to bore it out and there wasn't any dust of film or anything as others had mentioned. I have been running mine for almost 5 years now and have no complaints. The exhaust was fairly easy to install, pulling the old exhaust off of the crusty rubber hangers being the worst part. The only thing I would change is the exhaust tip....now that I have a high clearance rear bumper, the turndown is the lowest point on the rear. I will have to cut it back at some point.
 
If you want an exhaust that sound like the stock exhaust then just buy a stock (OEM) exhaust. Everyone here on this board knows that a Flowmaster has a rather loud abd unique sound.
I bought the Rustys cat back kit with the FM 50. It fit like a glove. Easy to install and needed no modifications.The sound was a little louder than I would have like especially at 30 to 40 MPH on city streets. Highway was never a problem. I spoke to an engineer at FM about it. His advice was to reduce the 2.5" pipe from the muffler out back to 2.25". I reduced the section that run along the gas tank to 2.25" and that made a world of difference.

This link from GoJeep www.go.jeep-xj.info/HowtoExhuast.htm has good infromation.

I have seen (I think here on this forum) a comparison between some popular mufflers. It is important to note that the Flowmaster may not be the best flowing muffler out there. However, it flows way more than the CFM and the RPM of the 4.0L would ever need.

Those like me who want a cheap tough and easy to replace cat back I would whole hartedly recommend Rustys cat back. There is an exhaust out there for every taste. What do your taste buds desire?
 
Mine came with the Borla in it from the previous owner. At first I thought it might be too loud. I have grown to like it.....

BTW, my exhaust is loudest at about 2-300 RPM when driving through town. On the freeway it's nice and mellow.
 
I've read that the flowmaster design that is best matched to the I6 is the 70-series. Something about the 40 and 50 series design that doesn't go well with the I6, those are a better match for V8s
 
KMK172008 said:
Flowmaster's are some of the worst flowing mufflers. My friend has your exact setup on a HO motor with headers and it sounds like a tractor. i'd go with a dynomax or a gibson or ANYTHING but flowmaster. I gotta say Glasspacks sound great too. been meaning to make a video of my glasspack and headers
Click to expand...

Ive only heard good about flowmasters... i wish there was a way i could know what my shit is gonna sound like before i buy it. I might get like a gibson header and high flow cat and then a 50 series
 
here's the info I was thinking of
"6 cyl. models have been tested with 3.0" and we found that they have better performance with 2.5" and Flowmaster 70 series mufflers. (If you get a muffler that is too loud, it will resonate and sound "cheap", which is why we spec these specific mufflers for each engine. Trust us on this. :)"

from this page
http://www.kevinsoffroad.com/exhaust.html
 
I put a flowmaster on an '89 that I had with no cat and I think it sounded really good. I am not sure if it was a 50 or 40 series though. It sounded a little like a 5.0 mustang. Hope this helps.
 
I had a 40 series on my 89. It was to load with no carpet an exiting just in front of the back tire. On my 92 the previous owner had the cat stolen. I put the 40 series form the 89 on it for a quick fits. That was way back in February and it's still way to load. Sound a lot like a poorly tuned SBC. Tomorrow I'm going to replace it with a turbo cherry bomb. I got it for free so I figure its worth a try
 
Mudderoy said:
Who makes the glasspack that you have? Is it too loud driving into the neighborhood at 3am?
Click to expand...

I have no idea who makes it. It was on it when I bought it. I like the sound level myself, it's not too bad at 75 MPH. Withought a cat though it is a bit louder. It is fairly loud but no louder than my friends Renix with a 40 on it, witch I also like the sound of. Idling around it's pretty quiet, but if your foot is in it anyone nearby will know it.
 
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