Okay, I know I ask alot of questions on here but this ones actually not about my Camaro. This question is on behalf of my brother about his 96 or so Jeep Cherokee. He has one with a V6 and is generally pleased with it, but when he goes over a pass somewhere around his college his car lags a bit due to the elevation. Now he wants a little more power, but mostly he just wants the power to not die so much up there. Any recommendations for him? I said a K&N and exhaust work should help alot towards his goal. How but it guys? Help him out? Thanks.

 

TB,

Elevations can be pretty tough. These are the places that a MAF system excells, since it actually measures the mass of air entering the engine. I would suspect a newer Jeep would be using a MAF, but I'm not certain.

The best solution would be a turbocharger, but that might not be an option. Aircraft piston engines have had great success with turbos at high altitudes for decades, and even turbojet and turbofan engines benefit from a similar effect.

Obviously, a good clean air filter is a good start. A less restrictive exhaust may not be as great a benefit, since there really isn't that much volume of air moving at those elevations anyway. Still, there is always an argument for a free-flowing exhaust system.

Another thing to monitor in elevations is the coolant temperature. It is very easy to overheat at altitudes, since the heat is rejected less effectively. If the PCM detects a higher engine temperature, it will tend to lean the fuel mixture and retard the spark timing, which simply adds to the problem at altitudes.

It might be worthwhile to consult a Jeep dealer, since they may have a solution similar to what GM had for their cars destined for higher altitudes. IIRC, there used to be some adjustment made to programming on GM cars to correct this. The MAP engines were particularly sensitive to altitude changes, and I seem to recall some TSBs that involved a replacement PROM.

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Later,
Vader
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If you want to beat the World, it might reach up and pull you down...
Adobe Acrobat Reader

 

hmm, thanks for the suggestions, i' ll tell him to ask what his dealer has to say. i think we will do the cat, and filter like i suggested anyway as well.

 

there isn't a v6 available in a jeep cherokee. for what he has though, they do make a cat back system as well as cold air induction systems. i believe mopar makes a performance computer also for it but there should be plenty of companies like jet or hypertech that make plug in performance modules for it.

 

Yeah, aren't the inline-6's?

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

correct.

 

yeah thats correct, i forgot guys, cut me some slack