We have a 1998 Wrangler 4L with 35,000 miles. Got the basics, 2" lift, wheels, tires, Gibson exhaust, lights, etc. But we need MORE power, and we have money to burn. We're gonna make it the winter project. Any suggestions. I'm new to the 4.0L I6... Thanks
Sell the engine with the computer get at lest $1000 for it then look into a v8. You can sell the tranny and tcase too. Gives you more options if you do the whole drivetrain together. Look on ebay for what used parts are going for.
There was a thread not too long ago that answered this. I remember the 4.0 upgrades for more power as:
1) K&N air filter
4)Performance injectors (larger)
5)Better exhaust - cat back system with high flow cat
6)Stroke the 4.0
7)Internal engine mods
Lets do the #'s first.....
Stock 4.0 FI is pushing about 165 HP
Stock 4.0 HO pushes about 185
All the above mods will help a little....but at the end of the day, at most you are going to get at most about 10% more HP...(under the best of conditions).
The whole is not the sum of the parts...this is the same problem engine builders have been having for years...the most common was the kid who put in the "Full Race Cam" on a stock engine and wondered why his car ran like *&$#. The truth is, there is not much you can do the 4.0 without taking it all apart and doing some internal work. Then you have the issue of the FI being matched to the new cam and other mods. Believe me, even a mild cam will throw off the computer (my 89 Cherokee is only getting 10-12 MPG).
Then there is the issue of drive train. Any more power and your going to trash the stock D35 in no time.
So...if you really have money to burn...give it to me..I'll modify my jeep first and then show you how to do it....
Just kidding...but actually, one of the suggestions above is the way to go...sell your 4.0, tranny and computer for $1200-1500...find a good doner vehicle with 350 and auto tranny..pull it and the computer out and slap that in your jeep. Then after you grenade the D35 on the first burn out, slap in a D44 or Ford 9" with 4.10 gears and ARB lockers. It will have plenty of power and still do nicely on the trails.
Whew. Lots of choices. Thanks. I love the idea... BIG BLOCK...But I may be getting in over my head with that one. No engine lift, etc. Wanted to do it ourselves. mmmm, how do you get rid of a 4.0L Wrangler engine anyhow? Anybody need one?
If I keep the I6 and went the Clifford way you guys think only a 10% power pick-up is possible?
Most of the "bolt on" mods do virtually nothing for you. A bored out throttle body gives you the illusion of more power because it gives you more throttle opening for every mm of skinny pedal application. Most of the rest don't do squat until you've exceeded the stock intake/exhaust capacity ...which is pretty much at WOT at high rpms (which you aren't likely to be at very often). With a K&N ..you "may" ease the factional percentage of hp the engine consumes drawing the air into itself ..again you're looking at nothing of any amount except at near WOT.
Look at all the data on the dyno tests for all these bolt on mods. They start the graphs at around 2500 rpm ...and most of the "very little" hp/torque increases, if any, are usually in excess of 4000 rpm. How often do you wind it up that high in 2WD? Unless you're trying for the ulitity vehicle position in "Fast and Furious" ...that is a street racer (yeah, right) ..why bother?
If you want to "perceive" more power ..get the bored TB