Quiet Custom Offroad Exhaust

[Irish JK]

Humm interesting....can't stand the sound of my rice rocket dynomax comp.

 

[raycn]

I just went with the Borla single cat back. All stainless and quiet until you really stomp on it.

 

[turbineguy]

I have been scouring several forums to get feedback on a few exhaust systems that eliminate the rear muffler on a JKUR. I have had my 2014 JKUR for several months and recently decided to move towards the EVO DTD front and rear suspension and upgrade to long arms. The two pre-packaged exhaust systems I looked at and considered buying were the Magnaflow 17143 or the Dynomax 39522. The issue I had with both was the feedback on several forums for people stating it was too loud, it droned, or it sounded raspy like a civic. The rep from Dynomax on the forum, exchanged messages with me and understood my need to keep the jeep quiet for my fiancee, and was kind enough to provide suggestions on keeping the factory resonator upstream of the 14" canister muffler offered by the 39522 system. Though I truly appreciate the candor from the vendor, the more I thought about it, the more I felt that it was a shame to buy an exhaust system only to butcher it. I decided to take it to a custom exhaust shop to have a custom stainless system installed.

When I got to the shop we discussed utilizing a 6" round 14" long 2.5" inlet/outlet canister muffler with the factory resonator in place. I knew that this would scavange more exhaust energy than the canister muffler on its own. What I ended up going with is a 24" long 5x8 oval 12286 muffler where the factory resonator resides and dumping by the skid of the rear drivers side control arm (factory control arm skid location). All pipes were stainless and I was able to keep the muffler tucked up higher than the factory resonator.

The end result (dont ask for sound clips because Im honestly too lazy to take videos) is a VERY quiet exhaust system. Lets put this in context. Its louder than stock, but not much. You can definitely hear it when your foot is on the gas and you are accellerating but its not bad AT ALL. I would be surprised if anyones wives or girlfriends complained. At 60mph (on 37" tires and 4:88 gears) it doesnt drone at all. At 70mph you can hear the exhaust, but the wind noise from my light bar and the tire noise from the toyo open country's FAR exceeds the noise of the exhaust. At 80mph ~3000rpm), the exhaust noise is there but everything else is noisier. At 85mph it quiets down to a nearly imperceptable hum again.

Basically I think the longer oval muffler solved the problem many here are looking for. Unfortunately its not a kit, but the result is a clean looking full stainless system that cost me less than $300 installed. (actually $307 with tax).

I just wanted to say thank you for the inspiration. I went to a local custom exhaust shop here and had something similar done.

They installed a HP-2 Hushpower muffer right behind the resonator. I also had them fix my crossover which was rattling against my skid. They managed to keep it pushed back, but raise it up a little to give me clearance. They also put a nice little bend in it to give me a little extra clearance.

The sound has a quite rumble at when I hit the gas, more so at lower speeds. Nothing obnoxious, but it does sound cool. At highway speeds, even with the doors off I can't tell the difference between the stock system.

Good luck on the rest of your future build.

 

[jhires]

Thanks for this thread along with all the ideas, and pics!
I've noted in the past that I wanted to go with a different exhaust system, but that I also wanted quiet. Glad to see people doing just that. :thumb:

 

[chipper]

Looks great.

I also wanted to get rid of the stock muffler out back but did not want it to be too loud. I did something similar with a Dynomax Super Turbo where the stock resonator was followed by a six inch round can similar to the Dynomax Evolution.

Tight fit but very quiet (stock quiet) and sits tucked up above the frame rails for the most part except for the back 2-3 inches of the 6 inch can where the frame rises for the rear axle.

A friend owns an exhaust shop so was lucky to play around with a few options. A 4" can that Magnaflow makes fits better/higher but it resonated and droned too much for me so we went back to the 6". I figure if I bounce off of a rock it'll just be self cleared for the next time.

What is the model # of the dynomax super turbo you used ?I can't make it out in the pic. Also if you stayed with all Dynomax is that 6" can the ultra flo welded round? What # ?
Also did you stay with the same diameter inlet/outlet size or go bigger towards the rear?
I'm wanting to copy your setup with all dynomax. Want to get rid of muffler in back but don't want the loud noise, my brother just did a custom exhaust but it's still to loud for me.
Do you still like it? Or if you were to change anything what would you do different with it?
Thanks

 

[SaddleTramp]

What is the model # of the dynomax super turbo you used ?I can't make it out in the pic. Also if you stayed with all Dynomax is that 6" can the ultra flo welded round? What # ?
Also did you stay with the same diameter inlet/outlet size or go bigger towards the rear?
I'm wanting to copy your setup with all dynomax. Want to get rid of muffler in back but don't want the loud noise, my brother just did a custom exhaust but it's still to loud for me.
Do you still like it? Or if you were to change anything what would you do different with it?
Thanks

Sorry, inbox is cleared now...

Pretty sure it's a Dynomax PN#17731. I had a 6" round Magnaflow can that was installed right after (downline) the oval Dynomax but after I went to the Double Throw Down rear suspension, we put a 4" round Magnaflow can after the Dynomax (Dynomax oval was installed in the factory resonator location) muffler and I really couldn't notice a difference in sound and it gave another inch of clearance.

Actually, all of it fit flush with the frame rails or better and I got a lot of compliments on the quietness and sound of it. I'm getting old and this was very quite, close to stock, but also very tight up to the tub and great to keep up and out of the way.

I would have done a Dynomax 4" round too but my buddy's shop for some reason doesn't carry them, only the Magnaflow 4 inch round's, but but he does a lot of the Dynomax Super Turbo oval muffler's for JK's and started adding the 4" round downline after he did mine for those wanting a little more quite ride.

 

[SmokinV10]

All if I were to do this again, I might go the way that saddle tramp recommended. Mine works, is pretty, quiet, and does not drone. The issue is that it hangs about 3/4" under the frame rails and has gotten hit a few times on the rocks.