Topic: Bored out Throttle Body

[RNandKT]

So I have 2 TJ's at my house, well actually I have one and my wife has one ;-)

Anyway both are 97 TJ Wranglers and both with 4 angry squirrls under the hood. On my Jeep before we got my wifes, I had to swap out a motor (found one with only 77K miles for $250 so way too good of a deal to consider swapping to 6 cyl or anything else). At the time I wanted to squeeze a few ponies and so I found some rebuilt Ford injectors and a throttle body from a 4.0 and tossed them on there. It definately runs smoother and seems to hold a highway gear better, and gained maybe 1-2 mpg back that I lost when I put a lift and 32's on it.

All in all pretty good. When we got my wifes TJ, of course we immediately lifted it and the difference was a little more obvious when comparing side by side (although my engine does have a lot less miles). I used my same source for the Ford injectors, but could not find another cheap 4.0 throttle body to save my life. Everyone wanted $50 and up. So I finally ended up coming across this on ebay. A service to have the throttle body bored out for $59 plus shipping and decided to get it done. I know it has been done previously on this forum, but seemed overkill compared to the expense and usually I could find a 4.0 throttle body for around $20.

http://www.ebay.com/itm/111296829505?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

Well so I went ahead and had my wife's throttle body done. Nice guy to deal with. Very friendly through email and really quick turn around. A bit over a week from when I sent it to having it back. I just barely installed it so might take a bit for the ECU to adjust but this week I plan to test it against mine to see if it is worth it compared to just getting a junkyard 4.0.

I attached some pictures of how it came back and will update a review when I have a chance to compare both of them. The little bit I did drive it, it seemed more eager in the bottom end but we will see.

[grumpygy]

Did you also open up the intake to match.

We have a guy on here who also does the throttle bodies and does spacers also.

http://4bangerjp.com/forums/index.php/topic,4044.0.html

This link is for the intake boring.

http://4bangerjp.com/forums/index.php/topic,6008.0.html

[RNandKT]

Yeah I took a dremel tool to the intake. Update you guys in a couple week to see how this compares to the 4.0 throttle body.

[Bounty Hunter]

Looks good.  A high-flow intake would help that throttle body a lot, I used a stock TJ 4.0L airtube with a conical filter.

One thing I add to my TB's is bead blasting, returns them to like-new condition.  If aesthetics are important

[RNandKT]

So had a few weeks to test this out and compare (1 of those weeks being in Moab). The bored out 62mm throttle body on my wifes Jeep feels a little more "eager" in the low RPM's but thats about the only difference compared to the 4.0 throttle thats on my Jeep. We even did a straight out drag race and in first and second gears my wife jumped a couple feet in front of me, but by 3rd, 4th, and 5th, she just maintained that 4-5 foot lead all the way to 70 mph. On the Freeway they accelerated (what little acceleration you get on the freeway with 32's) exactly the same.

So really it is nice as it does feel a bit more eager in the bottom end, but I don't plan on doing it to my 4.0 TB. Maybe you would notice it  more if you had other mods to compliment it. I have the Ford injectors in both Jeeps, and have upgraded the air filters, but thats it.

I would say if you can pick up a 4.0 TB for less than $20-30 bucks, go that route, but if you can't find one, $70 isn't too bad to have your 2.5 TB bored out.