Jeep did a pretty good job with the stock exhaust. For the most part, it is tucked up, out of the way between the frame rails. About the only vulnerable place would be at the rear where it turns down. Even then, you would need to be wheeling on a pretty gnarly trail to come in contact with the tip of it.
As with most factory exhaust systems, it is also very quiet. For me, a little too quiet. Shortly after I upgraded my intake, I was looking for an exhaust upgrade that would flow better than stock, and add a little more in the way of sound when you put your foot into it. My first exhaust upgrade was an axle-back system from MBRP. I chose the XP-series, made of 16ga. T-409 stainless. This is a dual tip set-up. Here's a look...
What I liked about this system was it provided an improvement in flow, 22% better than stock, and it had a rich, mellow tone.
Here's a quick look at the install. This is the stock muffler.
To remove it, simply unbolt the clamp and pry it off the two hangers. The factory hangers are not the easiest to get off, I used a penetrating oil to help here.
Here's the new MBRP muffler about to go in. I have all the clamps loosely tight, which will allow me to adjust the muffler chamber and tips once I have it on the jeep.
This is a direct bolt in swap. the MBRP fit the factory hangers perfectly.
I adjusted the tips to get them up as high and close to the bumper as possible.
The MBRP XP has a nice tone to it. It sounds tuned, not too loud, and wakes up nicely when you're getting hard on the skinny pedal. Turn up the sound and give it a listen in the video below...
I ran this exhaust set-up for about a year, including my first trip to Moab. At this point in my build, I'm on 35's and my 3.5" lift. The last trail run we did on this trip was Fins & Things. This trail features some really steep descents that have you dropping the rear end down hard and sometimes making contact. Coming off a few of those, I could hear and feel I was making contact...
This experience got me thinking about a high-clearance exhaust. If I plan on wheeling my Jeep, which I do, I was going to need a different set-up for my exhaust. Back to the drawing board, time for some more research. For me, one of the more difficult aspects of deciding on which exhaust system to run on my Jeep is that there is not a lot of good sound clips out there for us to preview. This has us a taking a big chance on whether or not we like the sound output of any given exhaust. I'm hoping that the sound clips and videos I post will be helpful in that regard.
AFE Power Mach Force-XP
AFE Power has built a great reputation for quality products that are priced fairly and deliver outstanding performance. My criteria now was high clearance. If I could improve on flow by going to a 2.5" pipe, that would be a plus, and lastly, have all this in a quality stainless with a muffler that has a nice tone to it, and I'm in.
That thinking got me here, the AFE Power Mach Force-XP Hi-Tuck. this is a cat-back 2.5" exhaust system designed to provide maximum clearance. It's built with mandrel-bent 409 stainless steel.
Here's a dyno chart on it...
Here's a look at the AFE compared to my MBRP taken during the install...
And here it is installed. This is another unbolt the old bolt in the new swap that can be done in your driveway. The AFE fit perfectly onto the factory hangers...
In the above pics, you can see how nicely tucked and protected the new AFE is, up between the frame rails and high at the rear...
You can see in the above shot the quality and craftsmanship that goes into this exhaust system. The welds are beautiful. I was very impressed!
I installed this system shortly before heading off to my second wheeling trip to Moab. One of the trails we ran was 7 Mile Rim. The second half of the trail had several huge rock steps. You can see where I make contact at the rear coming down off the steps, on my tow hooks, not on my exhaust.
The video below is a compilation of the install and road test of the Mach-Force XP, enjoy!
As you can see, I really like this exhaust system. After having it on the Jeep for roughly six months, I began to wonder if I could make it any better. The exhaust does not drone at all, but at constant interstate cruising, you are aware of it's tone. I've been working at fine tuning the smaller details of my build to really suit my personal taste. I was looking to improve the interstate cruising experience.
After another round of research, I decided to add a resonator into the mid section of the exhaust, just as the factory was running. The idea here being trying to change the pitch of the exhaust. The resonator I'll be using for this is from Vibrant Performance.
The Vibrant Ultra Quiet series of resonators feature a "true straight through" design. In vibrant's own words, "originally designed to help eliminate the rifling noise that is common with most 6 cyl. and 8 cyl. engines equipped with straight through performance exhaust systems". The Ultra Quiet is constructed of 304 stainless. Here's a look at it being fitted on Rubi...
So how is it? This worked perfectly. It took a certain pitch I had in the Mach-Force, and dialed it out. I was a little concerned prior to installing this that it may take all the good qualities of the Mach-Force out. Things like the deep growl when you get on the gas, but it did not. The nice deep tone is still there, but the pitch at high speed/rpm has been dialed out. You now find it easier to talk comfortably or listen to music while cruising down the interstate at high speed. I feel I now have the perfect exhaust on my Jeep.