I may start a war by asking this question......what is a good after market cat-back exhaust system? I have a 2007 JKU 4door 3.8. I've tried doing some homework on line and everybody is better than the next guy. I have visited YOUTUBE but the sound quality is just not there for me. I'm looking for a good throaty sound, not sure if I'm going with single or dual. Have you noticed any fuel in/decrease in mpg? Any added power?

Semper Fi, Drew

 

Been going through this too. I think I'm going afe

 

Subscribed....wanna see the answers too.

 

From what I've heard a dual outlet will decrease power..also everyone will have a different answer..I personally like no drone in the cabin..want it to sound stock but like a little noise out the back

 

Well i have had the afe 3" on my 08 jku for 2 weeks now with a kn drop in filter. I can feel the air going into the intake my first trip with it I spun the tires I have 34 inch toyo mt and at the moment i am getting better mpg. around town i can feel the tires grab the road and before i could not. the thing wants to go now for sure.at idol its not loud at all it has a little rumble to it.I also have an automatic with 373 gears bumper winch and a 3.5 lift .

 

Here is a picture of the jeep.good luck with your choices

 

I've got a 2011 rubi with the 3.8. I've added the banks power intake and monster exhaust system. For me it improved off the line drivability. Fuel economy maybe an extra mpg or two. Sounds good, easy too install, even for an old fat guy. Butt Dyno says it helps. A lot of folks say save your money for other mods, to each his or her own. I have no regrets for the money I spent.

 

I personally wouldn't spend the money on a full cat back. It's not going to do you much good in my opinion on these jeeps. I'd just pick a muffler based on the sound you're going for, mild aggressive ect.

Friend of mine has a flowmaster super 44 ($80) clamped in the rear stock location on his 3.8 and it sounds pretty good. Sounds better and deeper than a good number of full cat back systems I've heard. I myself have a flowmaster super 10 where the resonator was on my 3.6L ($60). Not everyone's cup a tea but about as aggressive as it gets :thumbsup

https://www.dropbox.com/s/ql8pal44hh...2015.37.56.mov

 

I'm very happy with my Dynomax rock crawler cat back system. Had it on for over a year and it sounds better now than when new. Butt dyno indicated a slightly better feel. I just added the AfE stage 2 si intake and super hips flashpaq, all I can say is wow! The total combo of exhaust, intake and tuner definitely woke up the 3.8. It's not a sports car, but noticeably better pull now and is able to maintain speed uphill.

 

I have the flowmaster (super 40 I believe) and man is it loud. Start up sounds great with an amazing grumble. When you take off it's really nice. Drone isn't too bad nothing some low to mid volume radio and cure. Mpgs will decrease, that is because you love the sound of it and won't be able to keep your foot off the pedal!