a little more jhuice...

[SwampSinger]

I was looking to had a little humph to the good ol' 4.0...

The only aftermarket parts that I have  to help to get more power is the header and the 2.5" cat back exhaust system....oh yeah, I forgot the K&N air filter .

I don't want to go crazy. My truck is a little heavier now and  a little more juice might be good. 

I was thinking of changing the air intake system and adding an aftermarket throttle body with a larger diameter or adding a throttle body spacer. I have to do some research.  I don't know if it makes that much of a difference. Is it worth it?...

Let me know what chu think?

[born2jeep]

I cant remember what year yours is, but if its 98 or older you could put a 99+ intake manifold on. Throttle body spacer is a waste of time and money from what I have gathered over the years. Boring out the TB or getting one that is already bored is good for a few HP. I think a cone style intake system would be a good start.

Other things you could look at...Changing your fan set up to electric. If your running steel wheels, you could go to aluminium, it will make a difference.

Or just go the easy cost efficient route of changing it to a stroker. lol

Sam

[hps4evr]

maybe you should start useing that fancy new machine in your basment more!!! that will knock some weight off the drivers side;)
a throttle body spacer is useless really. a bored throttle body would help, an intake and air filter will help. pick up the latest JP magazine, they tried out a bunch of intakes and other power adders. a good one that seemed not too expensive was a cam swap.
and yes, a full electric fan would help too.
of give up and buy a yj;)
hehehe
ttyl

[BlackYJ]

Dom, put a Comp Cam in.  I was riden in a 4.0L with one and it was a rocket.  This is on my to-do list and also look at some 24 lbs injectors.  rws posted a link to get some from the states.

[cablesmurf]

Come by when I get back from Mexico and take my Jeep for a spin...it has alot of snap.

Here's my setup:

RE 62mm throtle body
Airaid TB spacer (these are more for towing than anything)
K&N cold air intake
Banks header
Flowmaster muffler
MSD coil blaster & 8 mm plug wires
4:56 gears
33" tires

[BlackYJ]

4:56 gears
33" tires

Thats the problem right there, he only has 4.56 gears because of the 8.25 axle.

[calltrex]

i would put the extreme 4x4 cam in

[4PLAYZJ]

Drop in a chevy 350 and be done with it 

[Bnine]

The can will be the only one you can really notice Dom.

Ideally, you want to find a 95 head, and get Jeff to rework it for you, then install it with the came.

The only major difference between our xj's is mine has the 95 head. Without a doubt that head breathes better providing smoother power.

There is a mild change to the cams as well, but really, its the head that makes the major difference.

The reason throttle body's and headers dont make a realy significant difference on 96 and later 4.0's is due to the changes in cylinder heads, causing a lot more restriction.

Also, to really get better breathing with a spacer and bored throttle body, all  three components should be honed out to match. Intake inlet, spacer, and throttle body.

Mustang 24 and 26lb injectors swap directly on to 4.0's. If you get an aggressive enough cam, they would potentially make a difference as well.

Just replacing the stock injectors with multi nozzle (bosch) style injectors make a slight improvement over stock due to better fuel atomization.

There are tons of things to do, it takes money, but can be a bit frustrating because the gains are never very large with 4.0 mods.

[rws]

Lots of info here
http://www.jeep4.0performance.4mg.com/index.html

[SwampSinger]

Thanks guys...


I think it will be a project for next winter.  If you have to do it ... might as well do it right.

[hps4evr]

i heard any head from 1991 to 1995 has the higher flow design? bill can you cinfirm its just the 95?

[Gearhead]

I've been away on another course for a week ,  otherwise I wold have added a few comments .

91 to 95 HO heads are the same casting    # 7120 ,   beyond 95  ,   as EPA  regs were tightened and will continue to be , the heads became a little more restrictive , most noticable when looking at the exhaust port.
More grinding is necessary ,   time is money = more expensive to port these castings.

We'll talk some more about this soon Dom , I have an idea 

[Bnine]

Thats right, 91-95. I just always refer to 95 as thats the newest year you can get for that casting, and 95 seems to be a pretty common year.

[SwampSinger]

I've been away on another course for a week ,  otherwise I wold have added a few comments .

91 to 95 HO heads are the same casting    # 7120 ,   beyond 95  ,   as EPA  regs were tightened and will continue to be , the heads became a little more restrictive , most noticable when looking at the exhaust port.
More grinding is necessary ,   time is money = more expensive to port these castings.

We'll talk some more about this soon Dom , I have an idea 

Kool... Thx...