I watched Stacey David's Gearz recently. He did a piece on getting more performance out of a pick up truck doing three modification: large diameter cat back exhaust, free flow air intake, and a computer gadget to reprogram the vehicle computer. He claimed to take a stock engine with around 300 HP and get an additional 35 HP and 50 ft-lbs of torque out of it as measured on a dyno plus get better gas mileage.

- Is this possible on a Jeep Cherokee?
- Has anyone done this successfully?
- If so, what was the improvement in performance and gas mileage was achieved?
- What products were used?

Thanks.

 

FWIW and what u paid for it. LOL

http://www.jpmagazine.com/techarticl...ies/index.html

 

Your best option would be to buy a fast car

 

An engine is just an air pump in a sense, so it would make one think that more air in(plus fuel, spark) and more air out would improve performance. But from what I read all over this forum, the 4.0 has a problem adhering to the rule. I'm reluctant to do the whole bolt-on shabang. Before I got my '01 2WD I was shopping for a CAI, header, TBS, and straight pipe(no cat) exhaust. Then I jump on here and you hear this and that, kind of discouraging. I would love to be sitting somewhere between 250-275bhp and 300lb-ft if possible, maybe even 300-300. I don't go off-road, and maybe that's why there is a difference in opinions on this forum. Maximum performance while crawling has to be different from someone who enjoys high speeds in straight lines, right? I would like to hear what the experienced crowd has to say.

 

If you want THAT kind of performance out of the 4.0, stroke it for at least a 4.5

Immediate performance gains can be realized by upgrading the intake and exhaust. Like the JP Magazine link up there says, bore out the throttle body (or swap for an already enlarged one), get an easier to breathe through filter, and open up the exhaust. You will definitely see an improvement.

Chips on the other hand are a waste of time and money on this engine.

 

Chips wont work on us renix owners either! I prefer the simple mods that give more seat-of-the-pants power than dyno power. Who needs a dyno for a jeep anyway? It's a brick on wheels. If you hit 100mph pat yourself on the back. Then get to a gas station as quick as you possibly can cuz I bet that tank is now empty.

 

Ive only had My renix up to like 80-85

 

on a closed track performed by a trained professional....
seriously tho, ive dropped down to 4 and floored to pass many a trucks on the thruway... as far as performance chasing upgrades, I/H/E and thats about it..

 

Stacey David also gets paid the show us these magic chips and bolt on crap.

 

Does he get paid for wearing pants that are four sizes too small?

 

Spray the hell out of it

 

I call FAKE! The jeep is shifting normally if you listen to the rpm's. I think the camaros started off fast and then let off the gas. Jeeps are quick off the line, but not very much after about second gear. Just enough for the camaro to launch hard, then die down once it looks like the jeep will win. If that is in fact real, thats a fast as hell jeep. I give it about a month until the engine just dies from not being tuned for the nitrous.

 

Luckily I investigated this and contacted the owner. This is real alright but he only sprayed 3 bottles through it then took the system off. I have a 01 TA and I think a Jeep on a 100 shot would eat it alive off the line especially launching in 4 hi. Top end would be no competition but I think the F bodies just quit trying after a certain point. The LT1 cars are ridiculously slow anyways

 

Yeah, the jeeps have good torque at very low rpm's. They would definitely get off the line quicker. Top end is no match though.

 

However XJ with a LS1 swap would desimate all (not trying to quote The Fast and the Furious)