Jeep Wrangler Forum

Jeep Wrangler Forum (
-   YJ Tech Forum (
-   -   2.5 engine mods (

protron 10-27-2008 12:39 PM

2.5 engine mods
i have a 2.5 in my 95' jeep. i would like to make it run better. what mods can be done to improve proformance? i would like to do the most i can do to engine. i dont see myself putting in another engine. (engine is a rebuild that i recently put in)

also what has to be done to regear? i am rollin on 31" tires but next tires get are going to be 33".


Jeep_Geek 10-27-2008 01:35 PM

Not to much you can do that gives you much for your money

Some guys put 4.0 throttle bodies on. You can get them at a junk yard or off ebay pretty cheap.

Throttle body spacer... probably worthless

Intake... I guess

Headers are pretty expensive for the 2.5
gut the cat:rolleyes:

I don't think anybody makes a chip for the 2.5 YJ

Personally I have done absolutely nothing to my 2.5

Jeep_Geek 10-27-2008 01:38 PM

For a re-gear you will need to select a ratio that suits your driving needs

Is this an Auto or Manual Trans?

Just need to buy two sets of ring and pinions plus install kits for your axles.
They need to be set up correctly which will require a magnetic base dial caliper.
Most have a shop do them,

BamianYJ 10-27-2008 02:14 PM

Like 92JeepYJ said, there isn't gonna be too much you can do to get alot more power out of the 4cyl.

I think the 4.0 throttle body is probably the biggest one.

If you're looking for something to help you when your crawling check this out:
Nine pounds that make a difference for small motors

scrambler1 10-27-2008 08:11 PM

you do not need to even swap in a 4.0 throttle body. just take your time and take a porting tool and open up yours. That is what I did it does make a little difference. do not bother with the spacer. If you do go with exhast upgrades make sure a header and a high flow cat is part of the package.

protron 10-29-2008 12:34 PM

i had found this computer chip at . its says

1997-03 TJ Wrangler,2.5L 4 cylinder engine Manual or automatic transmission

Jet? Performance Stage 1 Module and Other Jeep Parts and Jeep Accessories by 4 Wheel Drive Hardware

is this the same 2.5 engine thats in my 1995 yj?

also what kit do i need for the new gears?

jgwalt 11-01-2008 05:17 PM

the throttle body makes a lot of difference. high flow air intake and electric fan are really the only easy things to do. I've heard the header makes you loose a lot of low end torque.

scrambler1 11-01-2008 05:30 PM

low end what?

Coyote_94YJ 11-01-2008 06:39 PM

Like everyone else said there isn't much you can do short of adding a turbo or a 4.0L. All those TB spacers and what not are a waste of time and money.

Here is a useful tool to help you figure out what gears to choose.
Gear Ratio Calculator

All times are GMT -5. The time now is 04:50 PM.

User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.