I have a 2009 Rubicon Unlimited. I have recently brought it to Colorado and it is struggling at high altitudes. I have installed a programmer, afe dry air filter and changed the gears. My next step would be to modify the exhaust. I'm considering the Axle Back option, Can anyone give me any ideas about which is the best and which ones to stay away from?

Thanks,

 

I have an aFe scorpion which is fairly quiet but no muffler is going to make much of a difference in power. Either regear or supercharge.

 

What jadmt said about exhausts (and programmer and air intakes) is correct: None of that will make a significant change. Regear that Jeep. And, I know you may be at high altitude where "regular" gas is typically 85 or 86 octane. Buy 87 octane no matter your altitude. That will make a difference. That is based on experience with a group of other Jeep JK drivers (some 3.8s, some 3.6s), who all commented during a trip that they were experiencing lower power, reduced gas mileage, and mild pinging using regular grade gas. We all started using mid-grade and the problems disappeared.

BTW: If you want a nice, but quiet note from a muffler, I really like the Dominion Off-road. It's a custom muffler, not very loud, but does have a note that sounds better than OEM. You can hear it some on this video ...

Listen to it starting at 1:09 ...

https://www.youtube.com/watch?v=A77-7i5DrpE

 

It has been re geared, i'm running 5:13's and i'm using premium unleaded. I did add a bottle of octane booster when I got to Raton the other day, it seemed to help my mileage a little. I think a lot of my problem was wind, its hard to push a square box down the road with a heavy quartering cross wind. I crossed over Independence Pass, and it was 3rd gear a lot of the way. Goes like hell down hill though!!!

 

The gains that you speak of are closer to the redline and they can rob your torque. If you think I'm kidding then pull your muffler completely. It'll rev freely up to 6k but it struggles off of the line......and is loud as hell getting to 6k.

With where you are- you've regeared (fairly deep at that) maybe it's time to drop your tire size or look into forced induction solutions. A muffler isn't going to give you enough aside from a lighter wallet unless you have other reasons beyond 2hp to upgrade it.

 

Thanks for the info, I surely do not want the noise if there will be no gain realized from it.

 

If you have available funds, long tube headers with exhaust and a supercharger will do what you need. Although the ratio of oxygen in the air is the same at altitude there is less air per cubic foot which leads to power loss. The only real solution is to put more cubic feet of air per second into the cylinders and add more fuel. For off roading I am not a fan of turbo-charging due to lag and low RPM lack of torque. Several companies make good supercharger packages for the Wrangler. Just remember, more air and fuel in means more exhaust out which is why you want long tube headers and a new exhaust - to get the most out of your supercharger investment.

 

I also have the scorpion muffler from afe. It's got a nice deep note under standard throttle usage. Very quiet, almost factory, at highway speeds/cruising. When you stomp on the gas, it gets louder but nothing crazy at all. Great product. It also tucks way up out of harms way and will save you a few pounds of weight. Nice price note too.

 

Do you have the axle back or cat back system?

 

Axle back 😎