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Trials and Tribulations of 11Hemi's Custom Exhaust

2022 Views 9 Replies 6 Participants Last post by  klement1
Hello to all,

So I purchased an 11 Laredo X Hemi a few months ago. I wanted to give it a little rumble so I brought it down to the local exhaust shop to have some changes made. Here are my experiences with the different setups we did:

1st setup remove muffler, leave both stock resonators in place:

Quiet at idle with a good gurgle. At partial and full throttle, a very loud and pronounced twang to the exhaust note. Huge loss in torque, MDS not functioning properly. 16 mpg hwy. This was way too loud and I did not like the fuel economy dropping from 21 mpg. 9 out of 10 in terms of volume.

2nd setup replace resonators with Magnaflows:

Recommended to quiet Jeep by shop. Much quieter at idle, gurgle is reduced as well. Partial and full throttle is still loud with a little more torque but nothing compared to stock. MDS still not functioning properly. Mpgs are around 17 hwy. 8 out of 10 in terms of volume.

3rd setup put center muffler back in:

This is the point where I stopped paying for the work and the shop was working to make me happy with the setup. We put the center muffler back in and left the Magnaflows in. Let me say, if you want power, this is the setup to have. With stock being a 4 out of 10 in terms of sound, this setup is a 6. The Jeep goes like a scalded ape. Plenty of tire squealing and just absolute performance all around. Easily knocked a half second off of the 0-60. Feels like sport mode in auto. Sport mode is just nuts. After I got done flogging it, I did a test on the fuel economy. Highway mpg driving like the other two setups netted 14 mpg. MDS still not functioning except on coast and going downhill. Absolutely horrible fuel economy but awesome performance.


I brought the truck back and had the stock resonators put back in. I am back up to 21 mpg on the highway and nice quiet performance. I do not know the science behind the way Jeep set the engine and exhaust up but in my experience, fuel economy is best with the stock setup and the stock setup only. I ate the money I spent on the custom system and called it a life lesson. I did not find on here a good writeup of what happened when you replace the different parts of the system. Had I found one, I may not have done what I did. I figure I would write my first post here to maybe save somebody down the line the aggravation of trying to find out. Happy Jeeping
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My guess with the mileage drop, is that after you begin to hear how beautiful the Hemi sounds when accelerating at moderate throttle input. This leads to more rapid acceleration just to hear the motor, which leads to a drop in mileage when you hear almost nothing. lol just a theory, but so true for me!
I removed my muffler and put 2 magna flows up front and also removed resonators, with NO replacements. I will agree 1000%, it sounds sooo good when I'm on it, it's hard to not get on it. I will say this too, that once at speed, inside sounds like stock, quiet.
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