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General Forums => The Mess Hall => Topic started by: oldjeep on January 31, 2010, 01:20:06 PM

Title: Another 62mm tb install
Post by: oldjeep on January 31, 2010, 01:20:06 PM
Decided to try to coax a little more power out of the 2.5L.  Previously I had a stock 2.5L throttle body that Nutter had bored the bottom end out for me, which helped some.

This is a stock TB bored to 62mm, with a new butterfly and spacer.  (4.0L TB is 55mm).  (From BountyHunter)

First you need to put the new gasket on the intake and trace out what needs to be removed.  Then I took a rasp in my drill and ground it out.  Took about 5 minutes to get it looking pretty decent.  Only other mod needed was to tweak the throttle cable bracket up a bit so that the TV cable from my AW4 was sitting at the right angle to the TB.

(http://www.oldjeep.com/images/YJ/Jan2010/P1310001.JPG)
(http://www.oldjeep.com/images/YJ/Jan2010/P1310002.JPG)
(http://www.oldjeep.com/images/YJ/Jan2010/P1310003.JPG)
(http://www.oldjeep.com/images/YJ/Jan2010/P1310004.JPG)
(http://www.oldjeep.com/images/YJ/Jan2010/P1310005.JPG)
Title: Re: Another 62mm tb install
Post by: oldjeep on January 31, 2010, 01:21:05 PM
Initial impressions are just based on garage tests, but it seems to operate smoothly - idle is still around 900RPM.  I need to finish fixing my winch before I take the jeep out for a test drive.
Title: Re: Another 62mm tb install
Post by: Jeffy on January 31, 2010, 01:58:55 PM
Looks good.  What did you use to finish the hole?
Title: Re: Another 62mm tb install
Post by: oldjeep on January 31, 2010, 02:02:48 PM
Looks good.  What did you use to finish the hole?

The rotary rasp actually left a very smooth finish.  I did a once around with a little drum sander bit that came with my dremel as a finish.
Title: Re: Another 62mm tb install
Post by: Jeffy on January 31, 2010, 02:11:10 PM
Ah.  You can use a flappy wheel sanding drum to get a nice round opening.  Other wise a 2" sanding drum will clean it up.
Title: Re: Another 62mm tb install
Post by: oldjeep on February 17, 2010, 06:31:40 AM
Drove the jeep in to work today and I can definitly tell the difference.  Accelerates quicker and I didn't need to downshift as often or early when going up small hills.  Seemed to like staying in a higher gear better.
Title: Re: Another 62mm tb install
Post by: neale_rs on February 17, 2010, 08:11:16 AM
With so many people reporting good results from TB swaps I might just get around to installing the 4.0 TB in my parts pile.
Title: Re: Another 62mm tb install
Post by: Sine Deviance on February 17, 2010, 11:16:46 AM
With so many people reporting good results from TB swaps I might just get around to installing the 4.0 TB in my parts pile.

There's no good reason not to do it. It's cheap (~$20 for a junkyard 4.0L TB) and easy, and the gain is actually noticeable if you have a better-than-oem intake/filter.
Title: Re: Another 62mm tb install
Post by: Bounty Hunter on February 19, 2010, 10:28:11 AM
The 4.0L is a decent improvement but you still don't get the snappy throttle response you get from not having the taper beneath the throttle plate like the 62mm.
Title: Re: Another 62mm tb install
Post by: chrisfranklin on February 19, 2010, 02:20:10 PM
Drove the jeep in to work today and I can definitly tell the difference.  Accelerates quicker and I didn't need to downshift as often or early when going up small hills.  Seemed to like staying in a higher gear better.

Boring out the intake manifold sounds like a smart move.  Will have to do that to mine at some point
Title: Re: Another 62mm tb install
Post by: Torch_Ind on February 20, 2010, 04:05:58 PM
I have a 64mm in mine with no spacer and it was a greatly noticed difference!!!  complemented my pacesetter header!!!!
Title: Re: Another 62mm tb install
Post by: oldjeep on February 20, 2010, 07:16:41 PM
Was out on a snow run all day today and it made a big difference.  Only problem I had is that it is now happy to rev up and over 6000rpm - with no rev limiter you have to keep an eye on the tach ;)
Title: Re: Another 62mm tb install
Post by: 4BangN on February 20, 2010, 10:51:41 PM
Was out on a snow run all day today and it made a big difference.  Only problem I had is that it is now happy to rev up and over 6000rpm - with no rev limiter you have to keep an eye on the tach ;)
I have my MSD set to 5000 RPM.  So I don't have to worry about over reving.  I will be doing the 62mm TB swap soon.  As for the fact it is very cheap and seems rather easy to do.  If the results are that good.  WHY NOT DO IT!?!?   :beers: