i am in the process of buying a 2008 jk 2 door w/ auto trans, it is all stock but i plan to run a rockkrawler 2.5" on 33'" km2's or general grabbers, i want to regain some of the power i am going to lose going to the bigger heavier tire. so im looking to do an intake/tuner/cat (or axle) back exhaust but i have no idea where to start on a jeep for this stuff. im positive i want a intake that is sealed with a dry filter of some kind but idk which one, and i want an exhaust that is going to add a little sound but not too loud. as far as a tuner goes, i have never been a fan of any of the "regular" tuners like bullydog,superchips,or edge. i had a diablo on my old chevy truck and didnt care for it, i am partial to sct but it looks like i would have to have the jeep tuned locally with sct and i dont trust any of the local tuners on a dcx platform.So i guess i have to stick with the "regular" stuff, i like the look of the superchips trail dash but idk about superchips tuning. so what have yall used and been happy with?

 

I hate to be a downer on this, but in my opinion tuners, intakes (CAI), and exhausts/muffler will do little to nothing for power or MPG.

I've played with all of the above -- even custom tunes. On the downside: Most CAI's make it easier to hydro-lock, tuners can cause everything from detonation and drivability problems to corrupting the PCM -- done that too. I like a hi-tuck muffler for clearance, and a bit better sound, but no other advantages seen.



edit: Forgot to mention that CAI's often use filters that are less efficient to get a measurable increase in power on a dyno (at high RPM's) -- meaning more dirt particles, and more wear. Another detail is that the pressure loss across a filter, intake, or exhaust varies with the square of the flow -- meaning that the potential benefits are at the very high end of the RPM range at WOT.

 

Engines suck air in and blow it out. The better the intake and exhaust performs, the better the engine performs. It may be negligible depending on what is done and to what extent, but better breathing is a good thing no matter how you slice it. And the cost of intakes and exhausts are well worth the gains imo. Even if you don't "feel" something gained, the engine is running better and more efficiently.

 

No matter how large your so called CAI is you are still limited by the intake runners, and the electronics of the intake system. Years ago larger intakes would allow for better breathing, however not so today. In many casses you could loose power with so called CAI's especially the ones with the tubes made of metal.

 

I have driven a 3.8 jku that was tuned with a intake and stock exhaust and it was a night and day difference from a stock jku, problem is I have no idea what tunes and intake it had and it's been sold since and the owner was a dealer that just told someone to put stuff on it and has no idea what was put on it.

 

Any idea what gearing it had? Even stock, there are several gearing options. My '07 non-Rubi came from the factory with 4.10s, and now has 4.88s.

To answer your question, I'm running a Hypertech. Little "seat-of-your-pants" difference in performance, but the speedo is correct. Intake is an AEV snorkel, but I use my Jeep as a Jeep--a CAI wouldn't work at all for me. Exhaust is from Dominion Off-road. Tucked up high with very nice note, but not too loud (enjoy seeing the wildlife instead of scaring it away).

While I usually use my Jeep in off-road travels, this video will help you appreciate the exhaust's nice note ...

Campo Road, May 2014: http://youtu.be/A77-7i5DrpE

 

I'm really not sure what gear it had but even the owner of it said it made a night and day difference when he did everything

 

Some tuners make the skinny pedal more sensitive (change the throttle curve). In other words, less pedal travel for the same throttle setting, which makes it "feel" like there's more power for the same pedal movement. And of course, the placebo effect is powerful too.

 

i know the difference in a changed throttle curve and real power gains, i change vehicles a lot and have never left one stock every vehicle i have had in the last 7 years has been tuned and few of them put on a dyno.

 

Can you share some of the before/after dyno data, and what was changed to get the improvement?