I have an 08 jk unlimited x and i was wanting to know what is the best cat back exhaust system to use? Ive been told that some exhaust systems have to much flow and decrease performance. So if some one has had a good experiance with a certian system than will you please let me know?

 

The best cat back system will assuredly spur a little debate.

To keep exhaust velocity you don't want to run anything larger than 2.5".

Installing headers will help performance as well on the front side of the Y pipe. I had a thermal barrier powder coat job done to my headers before the install which keeps heat out of the engine compartment.

I'm using Banks stuff and I'm definitely happy with the performance, but certainly didn't do any independent testing of all that's out there. I'm much more inclined to jump on my soapbox and name names when something doesn't perform as advertised. My decision wasn't based on exhaust sound, but simply who I felt was going to deliver performance. I also didn't need the vanity of dual exhaust tips that weren't going to give any performance gains where the rubber hits the road.

 

That's rare enough to be quoted. I couldn't agree more.

 

I went with the Borla single axle back assembly. The factory pipe from the catalyct convertors looked good except for the dent at the axle so I saved a bunch of money by going the axle back route. The single exit was advised by Borla to preserve bottom end torque!! The dual outlet only provides HP at high rpm, not what a Jeep needs. There was a post a while back that proved on a dyno that dual exhaust on the JK actually provided LESS power. Check out the Borla website, great sound bites. I think I got the best of both worlds, a little more power, gas mileage (if I keep my foot out of it), great sound, super quality, and tucked up a little higher.

 

I think either the Woods or Cool Tech systems are real good. They are similar. If I decide to modify mine, it will probably be one of those. There's plenty of info on both on the forum.

 

Woods relocation kit.
https://www.jk-forum.com/forums/sponsoring-manufacturers-vendors-check-out-cyber-monday-specials-24/4xfix-hi-clearance-muffler-relocation-kit-52079/

 

x2, plus it relocates the muffler to a safer location....

 

Call me crazy but I enjoy the stealth mode that the stocker has. Maybe if one of these bolt on cat/axel back systems still provided the same performance with as much sound as the stocker I would probaly do it. Until then I will silently wait.

 

Thanks for all the info esecialy about the flowmaster 80 series muffler. i have one on my camaro and love the sound. plus it looked really easy to adapt to the stock exhaust.

 

Yep, poor little weak me with less time than money decided to buy an exhaust and have it show up on my doorstep.

A dual exhaust wasn't even a consideration as to maintain exhaust velocity with the small power plant you need to run 1.75" pipes, a crossover, ditch the Y-pipe and buy two catalytic converters. Dual 2.5" pipes are going to slaughter any low end torque and any gains would only be found at very high rpm horsepower.

I'm sure it sounds cool though.