TB Swapology

[jsawduste]

Bringing this back up from the dark ages. Want to try and have a single data point thread for clarification or those of us with limited attention spans.

Most of the info is from here
http://www.jeepstrokers.com/forum/viewt ... hilit=70mm

IF I am understanding things properly. I can snag a 2001-2007 Dodge, Jeep TB that has a 68 to 65mm taper (Chris`s post on page 1) and machine out the taper then build a new 68mm TB plate. And as I understand things Ryan is no longer offering 70mm TB`s .

Shawn's buddy is making adapter plates
http://www.ebay.com/itm/Throttle-Adapte ... 0813261913

BUT
we still need to modify the linkage of the 4.7 TB to work with our XJ/YJ stuff.

Then of course the intake manifold has to be opened up to take advantage of the increased diameter.

The other option is to simply purchase a F&B 68/70mm TB that has the correct linkage and bolts up without and need for an adapter plate.
http://www.fbthrottlebodies.com/products.htm

Painless comes in at around 400-450 bucks and I do not see any advantage over the F&B.

Looking at the Jeepers and Creepers site http://www.jeepersandcreepers.com/13601.html it doesn't look like they bothered to make a 70mm per Chris`s comments on page 4 of the above referenced thread.

Am I on track here or has my attention span wandered off again ? Perhaps your best buddies third cousin is machining out 4.7`s to 68/70mm with the correct linkage already installed ?

[jsawduste]

Thinking about this a little bit more.........Believe I have overlooked the obvious.

The 4.7 taper is BELOW the TP. Thus by removing the throttle plate, machining the bore to 68mm throughout the original 68mm TP can be reused, correct ?

[SilverXJ]

IF I am understanding things properly. I can snag a 2001-2007 Dodge, Jeep TB that has a 68 to 65mm taper (Chris`s post on page 1) and machine out the taper then build a new 68mm TB plate. And as I understand things Ryan is no longer offering 70mm TB`s .

The 68 mm version already has a 68mm plate. However, there is a taper above the throttle plate that needs to be machined out.

we still need to modify the linkage of the 4.7 TB to work with our XJ/YJ stuff.

Correct. Some people remove the WJ throttle arm and weld the XJ one on. However this will be an issue because they have removed the throttle stop as well. Meaning the butterfly is acting as the stop.. bad idea.

Crappy image taken with tablet shows this:

Looking at the Jeepers and Creepers site http://www.jeepersandcreepers.com/13601.html it doesn't look like they bothered to make a 70mm per Chris`s comments on page 4 of the above referenced thread.

From what I heard about a month ago they are still working on it.

[jsawduste]

I see what you are showing Chris. The omission of the stop would not be acceptable, as you mention.

The picture is becoming clearer that an aftermarket TB is the better, although not the cheaper, way to accomplish the extra diameter.

Perhaps contacting J&C might be a worthwhile endeavor to help push them to market the 68/70mm TB.

[wjtom]

as much as i hate to say this 505 performance has one in 70mm.seing he doesnt really have anything to do with making it he cant screw it up.

[wjtom]

pretty sure its an f and b anyways.I have one and its a pretty nice piece.

[jsawduste]

as much as i hate to say this 505 performance has one in 70mm.seing he doesnt really have anything to do with making it he cant screw it up.

Thanks Tom, but even the idea of sending them any $$ would be against my better judgment.

[jeepxj3]

Magnum Powers has a 85mm TB
http://shop.mpsuperchargers.com/Magnum- ... TB85mm.htm

[wjtom]

Im not even sure there is enough room between the bolts to mount that.....but interesting.

[shawnxj]

modifying the 4.7 tb to fit a xj/tj took me all of about 20 minutes and 2 tack welds but i understand not everybody has a welder but i'd imagine most people know a welder or somebody with a machine. the swing on the 4.7 is too short for xj linkage

[jeepxj3]

Im not even sure there is enough room between the bolts to mount that.....but interesting.

Would require modifying the intake manifold, making a new TB mounting surface/plate for the 85mm to bolt to.

[jsawduste]

modifying the 4.7 tb to fit a xj/tj took me all of about 20 minutes and 2 tack welds but i understand not everybody has a welder but i'd imagine most people know a welder or somebody with a machine. the swing on the 4.7 is too short for xj linkage

How about a picture Shawn ?

[SilverXJ]

Magnum Powers has a 85mm TB
http://shop.mpsuperchargers.com/Magnum- ... TB85mm.htm

I've seen that before. From the pic it looks rough.

[shawnxj]

modifying the 4.7 tb to fit a xj/tj took me all of about 20 minutes and 2 tack welds but i understand not everybody has a welder but i'd imagine most people know a welder or somebody with a machine. the swing on the 4.7 is too short for xj linkage

How about a picture Shawn ?

i'll get a pic tomorrow

[FlyinRyan]

I will be trying the 85mm TB soon on a Kenne Bell SC'd 4.6 . The truck already makes 8.5 lbs of boost with an F&B 70...we are upgrading the TB, making a larger diameter intake with a bigger filter, and adding a hood scoop all at the same time.