I've been thinking about doing some performance mods on my jeep for a while and was wondering if anyone had any suggestions on what they've done or what they would do differently? I've looked into superchargers but they are costly for the amount of improvement they offer. I've also looked into the stroker builds but they are probably a little advanced for me. I've also heard some talk about switching over to a larger v8. This sounds appealing but I don't know what it entails. How difficult are the engines to find? what other mods need to be made...that sort of thing. I'd also be interested in just tuning up the 4.0 that's already under the hood. This is a project I'll be working on over the summer and I'm not looking to spend more than $4K but less is always better. I'm currently running a k&n air filter. I know they get bad reviews for letting particles through but I've also heard that the stuff that gets in won't harm the engine so long as you keep it cleaned regularly when you change oil and do normal upkeep. What do you all think?

 

O dude. Don't swap your engine. swap= more weight less reliable than the I-6 4.0. and A lot of work. Don't do it. Don't wast your time finding every bolt you can get. The 4.0 was built stout. Bolt on's will give you better throttle response( I.E. air right when you need it through a less restrictive filter, gas through better flowing injectors etc....) you will not see any significant H.P. changes and contrary to popular belief you cannot feel a 7 h.p. gain from your exhaust. LOL it may sound better and flow better but its all in your head. If you want power; and a lot of it, you need to consider a supercharger. There are a few companies that make them. the one I have seen and felt in action is this
http://www.avengersuperchargers.com/
That supercharger rocks man. will run at 270-300 h.p!

Don't go with a V-8 swap. There is a reason we love the I-6

 

I have been wanting to build a 4.7 stroker since I got my jeep. I have just not had time/funds. That is the way I would look at going if I was gonna do something. I have seen a couple that had v8's swapped into them but I dont think that is a worth while way to go. The 4.7 is a strong motor and it off of all of our favorite platform.

 

idont know if it will inspire or help you but my intentions are to wheel the sh8t outa mine til it dies then look for a 4.0 if no luck im gonna do a swap with front frame build with tree fitty, th350 and np 205 twin sticked...... its much more effecient to do minor mods and use the "factory motor" then to go the route of heavy fab work and expensive parts to swap a v8 in. and from my past experience i havent ever liked the GC v8. neways re gearing shows some power gains if your running large mud tires mud terrains create some drag...especially superswampers...

just my ideas and .02

 

I do love the 4.0. I realize exhaust won't give me much gain, but I really don't need a lot. The 4.0 is bomb-proof and packs a good amount of power. I am mainly looking to keep my baby running smoothly, cleanly, and efficiently. I want her to purr real nice. That said, all performance mods will probably hurt my gas mileage. However I think that whatever I do will help me out driving in the mountains and when my jeep is under a heavy load. Both of these conditions are fairly common for me. I'm sticking with the I-6, a super charger might be feasible in the future but it sounds like bolt-ons are probably the mods I'm most interested in for now. What have you guys done and what would you suggest? Brands to trust or avoid? Mods I might consider with axles or gearing?

 

Id suggest going witha bored out TB. Its a easy and cheap way to gain a little more power that is noticable.

I got mine from strokedjeep.com and would recomend him time and time again.

 

X2 on the bored TB.

 

I bought a k&n cold air intake. I got at least 5 or 6 mpg better on the highway. From 14 mpg to 21 mpg average on a half tank of gas on a highway road trip. In addition to that i also gained a good amount of HP and torgue which is always plus

 

sorry there is no way you gained 5 to 6 more mpg from this mod. and even if you did you can not get an accurate mpg off of a half tank of gas.

 

Depending on the V8 you put in, it is worth it. For than kind of money, you could put in a ls1/2 or other variation of an LS motor. Even with a stock LS1, thats 320hp right there. LS2 is approx 400hp. Or, what you could do, is find a wrecked later model full size chevy 4wd with a 5.3 or 6.0L in it (maybe do a LS intake conversion.) and drop in the engine/trans/t-case. You would need custom or modified d-shafts but it would be a killer combo.

 

Why on earth would you put a corvette engine in a jeep?
stick with the I-6 man. An LS1 are you serious. He is not wanting to race his jeep in the 1/4 mile. lol

 

Know you cant say that e ls1/2 is a bad motor for a jeep I got a friend out here who has a scrambler crawler and that is what he is running. But in a cherokee that is a bit of overkill.

 

I bet if i kept on the highway for the last half tank of gas i would get still get 21. I went on the same trip in the fall and got 15 and a half pg

 

#1 Im not saying it's a bad engine. less reliable than the I-6 is very true.
#2 The cost of an LS1/2 swap would be insane. not to mention the cost of a new tranny and transfer case. To do that much work and end up with 300 hp would not even be worth it. I could slap a super charger on it and get almost 300 hp for almost half the price. That engine is a dumb idea to put in an XJ. The I-6 is a well balanced engine that is reliable and long lasting. When it comes to engines look at some of the famous cars out there that stomp the crap out the competition( includin vets) Supra ( 2JZTT, straight six) Nissan Skyline ( RB26dett, turbo straight six) BMW M3 ( m50 NA straight six)
Needless to say I am not claiming the jeep I-6 is in the same class as the engine above but still the I-6 is the way to go. If I was building a race car. I would have an I-6. I love em and they are one of the best engines. PERIOD.