Jump to content

The Jeep needs more motor...


SPLN SUX

Recommended Posts

So Jeeps are slow to begin with... and with the 4.0L 5sp, it really isn't all that bad in stock form. Even with the 31's on it, it still isn't bad from say... 0-40. It'll actually bark both the rear tires grabbing second. The problem is... the interstate... As soon as this thing hits 3rd gear, it is the biggest turd on the planet. Something has to be done to this thing because its honestly scary to merge into 80mph traffic with a jeep that MIGHT do 85 or 90mph.

 

An SBC swap is out of the question.

 

I bought a 3yr warranty with the jeep so I cant really do much of anything that cant be reversed quickly or not seen at all.

 

The superchargers are garbage for this engine and only produce like 60 or 70hp.

 

The turbo kits are very spunky adding 92hp and 80 some lb-ft at the rear tires on only 8psi... BUT its a lot of plumbing, especially for a air-water intercooler.

 

The other alternative is building a stroker motor which has several combinations making any where from 230-300hp and 270-350lbft... no real HEAVY machining is required either... but it does mean I'd have to start from scratch and then swap it in... much more involved then just bolting on a turbo kit.

 

Ultimately this car is for daily commutes and crawling around on trails... interstate travel is only because I have to in order to get to the trails. This wont be a highway vehicle... just a around town and light/moderate off road rig.

 

Thoughts?

Link to comment
Share on other sites

I was reading some info on stroker motors. They seem like they would do what you were looking for. I have a spare 4.0 block sitting in jeep in my driveway. But I have not decided what to do with it yet.

 

If you have not been to jeepforums.com yet I would check it out have some good information on there.

Link to comment
Share on other sites

Depending on whether jeep kept with the old ways or not you should have 3.73 to 1 diff gears. If you've upsized your tires from stock and want to make it feel like its got the same power as before you can regear to 4.10 to 1. This will of course give you more take off power at the expense of top end speed, but its a brick with wheels and thats probably not your biggest concern.

 

If you plan on getting a lift and bigger tires down the road you might want to just deal with it for now and wait until you know what your going to do since gears are a pretty expensive part of a 4x4 mod due to having to buy 2 sets.

Link to comment
Share on other sites

The top end is not the problem, its the time it takes to get to freeway speed. if you come off a ramp at 40mph, and it takes 10seconds to get to 75... that's a lot of ground that will be closed up on you in a big hurry. Interstates here are 75mph outside of the city, so often traffic runs at 80-85mph. I have to at least be able to keep up with traffic.
Link to comment
Share on other sites

I too have a jeep 4.0l 5speed. They are pretty doggie!! I have put on a Dynomax cat back and opened up the air box with a k&n. Have noticed a little more roll on power with 2-3 MPG increase with 30" tires. Have herd that the TB spacers work well, if your willing to spend the money the whole Banks Performance kit is amazing!! Went to school with a guy that had the whole kit.
Link to comment
Share on other sites

opened up the air box with a k&n.

 

If you do actually take it on trails DO NOT put a K&N kit on it. I've seen several Jeep engines get killed because those kits will drink mud. If you do any intake kit on a Jeep do it right and do a snorkle:-)

Link to comment
Share on other sites

If you do actually take it on trails DO NOT put a K&N kit on it. I've seen several Jeep engines get killed because those kits will drink mud. If you do any intake kit on a Jeep do it right and do a snorkle:-)

 

 

I would agree however i only drive mine on the street. It has only seen grass and light dirt outside of that. Snorkles kind of suck because you have to cut a big hole out of your fender. But they do look sweet!

Link to comment
Share on other sites

i have 265/75/16 tires and my 3 speed auto does fine on the freeway. As long as i get it to downshift to 2nd and make sure it's high enough in the rpm in 3rd. Its a dog from about 50-70 bc it doesn't downshift. Its 70mph down here, i usually go about 70-75 bc I have the top up w/ everything off so i get blown all over the road. Maybe im just used to slow cars since my other one is an escort...i'd love a 5spd
Link to comment
Share on other sites

he lives in colorado in the mountains it is a suitable daily the tires are just too much for the stock gearing

 

Well maybe i can find a set of Dana 44's off a Rubicon... they have 4.00 gears in them i believe... The stock Dana 30's on the X aren't good for much more than what I have now, so eventually I'd have to swap up anyway I guess...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...