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Upgrading Exhaust.... what Muffler?

milehilonewolf

NAXJA Forum User
Im upgrading my exhaust system this week and was wondering if anyone had some advice as to what muffler I should use.... i have read conflicting reports regarding 2 and 3 chamber mufflers used on v6 motors. Does anyone know which works best on the 4.0?

I have read people using the Flowmaster Super 40 series mufflers, and I was leaning that direction... I want and exhaust I can truly enjoy/hear (I have owned v8 powered trucks for years, and love the sound) I will be putting in a high flow Cat and an exhaust header with 2 1/2 inch pipe.

I saw that another forum user posted a thread today regarding which header people have found to work and last the longest on the 4.0 so I will keep my eyes on that thread to answer a similar question...

Thanks for your input...
Mike
 
First off the 4.0 isn't a V-6, it's an inline 6!!

Second, it's a matter of preference, but I'm not a huge fan of the flowmaster on a 6 cylinder. I used to have one back when I was 18 and sold that jeep when I was like 21ish. I put one on one of my XJs a few years ago (at 25) and it was just a tad too loud. It isn't way loud, but IMO, too loud for a 4.0L XJ. If it's making that much noise, it should be able to fly!! Plus, I like keeping as low a profile as I can, even with a lifted jeep!!

That being said, I'm a fan of the dynomax mufflers. Not quite as high quality as the flowmaster (the joints aren't all welded, but it's still pretty solid) but I like it enogh to run one on both of my jeeps!! They're slightly louder than stock, but not loud by any means. I let the driving skills do the talking, not the exhaust tone.
 
mjma said:
First off the 4.0 isn't a V-6, it's an inline 6!!

Second, it's a matter of preference, but I'm not a huge fan of the flowmaster on a 6 cylinder. I used to have one back when I was 18 and sold that jeep when I was like 21ish. I put one on one of my XJs a few years ago (at 25) and it was just a tad too loud. It isn't way loud, but IMO, too loud for a 4.0L XJ. If it's making that much noise, it should be able to fly!! Plus, I like keeping as low a profile as I can, even with a lifted jeep!!

That being said, I'm a fan of the dynomax mufflers. Not quite as high quality as the flowmaster (the joints aren't all welded, but it's still pretty solid) but I like it enogh to run one on both of my jeeps!! They're slightly louder than stock, but not loud by any means. I let the driving skills do the talking, not the exhaust tone.

Very well put I've put a flowmaster on my friends and it wasn't bad but it wasn't good either. I have a high flow cat and the dynomax setup, and I couldn't be happier. Plus the dynomax setup from jegs is like 130.00 shipped can't beat that. One little thing if you have an aftermarket shackle like me then the last turn where the tip is will hit it. I cut it off and welded on a turndow and all is well. The only thing I screwed up was putting the nut on my shackle on the inside and the plastic nyloc is now melted goo. Doh
 
Sorry about the miss-print of a V6 :) Should have known better....

Thanks for you opinions so far.... but is there any opinion regarding 2 or 3 chamber mufflers.... I have see posts in other forums around the web talking about 3 chambers are better for L6 and V6 motors?
 
ok. well,my buddy and i both run 10 series delta force race muffler from flowmaster. they are tiny. mines 4 x 9.5. my jeep isnt too loud, and it sounds amazing... trust me on this. doesnt sound like a v8, but it sounds better then any other jeep ive heard. i like it because its hard to hit my muffler on the rocks when its sooo small



_10_series.jpg


part number 9430109
 
lose the flowmaster, they dont sound the greatest and the do NOT flow very well despite the name.

Dynomax super turbo, all day, everyday. They sound great, flow very well, last pretty long, and they are inexpensive.

I am beginning to class the sound of flowmasters with the sound of rice rockets.
 
wolfpackjeeper said:
I am beginning to class the sound of flowmasters with the sound of rice rockets.

I wouldn't go THAT far, but I see (or hear) what you're getting at.

I liked the flowmaster on the MJ...maybe it wasn't so bad due to the longer tailpipe?? But on the XJ, sounds rice-ish kinda!! So, I traded it for someone who had just bought a dynomax for their v8 ZJ. If you had a v8 ZJ, I would recommend the flowmaster, sounds great on the v8!

Also, I have no idea how many chambers are in the dynomax....maybe 3?? Why not compare the mufflers by brand name?? EAsier than by chamber!!
 
Spintech Mufflers are the way to go. I have one on my XJ and had one on our old Scrambler. They sound awsome and flow great.
 
my dynomax muffler is going in the trash after 4 wheeling trips. its a great sounding and flowing muffler, but it cant take abuse. i'm picking up a red hot with the fancy angle pipes so it fits in the stock location. theyre durable and cost 15-20 bucks.
 
I have the dynomax catback. It sounds pretty good. It has actually started to sound really good in the past couple of weeks. I like the sound of a 40 series too. If you want something that is more mellow i would go with a dynomax. if you want it to be loud as hell put on a 40 series! :D JUST DON'T GET A GLASSPACK PLEASE!
 
Any old OEM replacement muffler will do. Weld some 1"x1/8 strap to the case bottom spaced apart an inch or so. Cover with some sheet steel (1/16 to 1/8 thick) and rosette weld in place.

Result is very tough muffler that is quiet and dirt cheap. FYI if you are going to slam the muffler on rocks expect to crack the OEM exhaust manifold fast unless you use a flex joint between the manifold and the pipe.

John
 
Nosigma: My interest has been peaked by your comment about using a flex joint between the manifold and the pipe... what exactly do you mean by this? Please excuse me, i tend to be a layman when it comes to the in depth technical/mechanical subjects....

Thanks again to all of your opinions... I have been researching all of your suggestions in depth... hopefully I can make a final decision soon..... this has been a little more difficult than I had imagined.

Nothing wrong with ample amounts of information....
 
Does anyone now of a link to actually hear what the dynomax mufflers sound like under an XJ? I have found a ton of sound bites with the flowmaster 40's but only 1 on the dynomax.

Im still leaning toward the flowmaster 40 but I could be persuaded if I had some decent audio to compare the dynomax.

I love the way the flowmaster 40 "seems" to sound at idle but a little turned off by their sound a high rpm's... do most of the aftermarket mufflers tend to sound so rice-ish at the higher rpm range, from the lack of V8?
 
I just run the stock exhaust system with a hollowed out cat:shhh" and a donated Flowmaster muffler.... Probably the only reason I use the flowmaster is cause.. well.. it was free. Can't beat free, right? Of course, being 18, it's all about who's rig is the loudest. I definitely take first between all my buddies. So far the only downside I found is that I can hardly hear my radio while I drive because the exhaust is so damn loud....


Edit: I read a lot of posts on this thread about the flowmaster sounding rice-ish. Any exhaust system (stock included) under any XJ i've seen, is the furthest sound from rice I can think of (well, with the exception of diesel).

Just my $.02
 
Milehilonewolf,

The post below has links with flex pipes. This is about the only way to fix the cracking problem. A lot of folks have had no problems with header systems. I have no idea if they bash on the muffler. I hammer my muffler frequently and have cracked several stock exhaust manifolds. The flex pipe got rid of the cracking manifold problem on the OEM manifold for me. Fingers crossed I have not had a problem since putting it in.

http://www.naxja.org/forum/showthread.php?t=954423&highlight=flex+pipe

John
 
I may be late to the table with this advice but don't go Flowmaster. Irritating sound at 15-1800 and they don't flow any better than stock from what I've heard... also, my butt dyno was unimpressed. Going to go glasspack when I have money just lying around.
 
how do classify irritating? from what i have heard, the flowmasters sound pretty good at idle and little higher... they seem to have a nice low rumble...., but as i was saying, the higher rpms are a little questioning...

Im not sold on the flowmasters, still considering the dynomax, possibly the Ultra Flow Welded one....
 
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