So i just picked up a 98 TJ with the 4.0 I6 and a 4" lift with 33" tires and i'm annoyed at how sluggish it can be. It jumps off the line but just doesn't hold after. Anyone know of any tune ups to add some ponies?? got a budget of 2-7 hundred
This, gear it low. It's a Jeep, you don't need power. I have a 94 XJ with the 4.0 HO, full cage, custom bumpers, D44 and Ford 9" with Krawler 35s. It's not fast, but it'll crawl through anything and let mud fly.
The 4.0 has a shit aftermarket, unfortunately.
Stroke it. How good are you with a wrench?
Do you know what your gear ratio is in the axles? I've got a '98 TJ as well with the 4.0 and 5 speed. Had 3.73 gears when I got it with 31" tires and did pretty alright for what it is. Then I put 33's on it and holy shit it was sluggish in the higher gears. 5th gear was basically useless unless I was going downhill. After a while I got 4.56 gears put in and it was a night and day difference. It put a ton of pep back into it and brought the top speed up to about 105 mph by my gps, albeit cruising at 75 on the highway was turning something like 3,200 rpm Some time after that I went up to 35" tires and it is noticeably more sluggish, though not as bad as with the 3.73 gears. If I had it to do over again, I'd say 4.56 is perfect for 33's and 4.88 would be choice for 35's.
Anyhow, point I'm getting to is that if you are geared somewhat high a good 4x4 shop could have you re-geared front and rear for about $800.
You've got the wrong vehicle for going fast. Maybe futz around with gear ratios, you've got enough gears between the engine and wheels to do lots of things with all the torque that 4.0 makes. Just dont expect to get Corvette type shit out of that truck dude, it's a climber, not a marathon runner.
CHARGE YOUR FUCKING PHONE JESUS CHRIST
Regear OP. 4.10 are recommended for 33s, it's what came stock on TJ Rubicon and they basically had 33s from the factory. The problem with this is the Dana 30 in the rear. Putting money in that is a waste, it will break.
I would suggest an 8.8 with LS from an explorer. I believe 4.10 is common for that axle. Then regear the front. Go on jeepforum this is a very common conversion.
>in European standards it was not that slow
I've owned several jeeps. The 2.5 is as gutless as it gets. That being said offroad they are fine, actually being such a dog is a benefit, I've wheeled with more than a few guys who had automatic 4 cylinder wranglers. They did not have enough power to break anything.