Making a throttle body spacer work on a RENIX

Performance mods and Advanced Stroker discussion.
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Muad'Dib
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Making a throttle body spacer work on a RENIX

Post by Muad'Dib »

I was having trouble finding the info to make a throttle body spacer work with my RENIX XJ (87-90 Cherokee). So i figured i would post here.

Throttle body spacers are truly a waste of money unless you have a carburated engine. They will NOT improve gas mileage, or give you big HP/Torque gains. They will give you slightly more plenum volume thats about it. If you can make your own and / or are able to get it under 30 bucks go for it. Just dont be suprised if it does nothing.
Im also installing a 61mm TB, so im just trying to compliment that mod. This will all end up eventually being replaced by a HO (91-96) set up for the top end when i build my stroker...

Things needed:

1" Throttle Body Spacer (thanks oletshot)
Extra Throttle Body Linkage... from the TB to the "teeter totter thingy"... lol (Free.99 at the junkyard)
3 TB Bolts that are 1 inch longer. Size = 3/8-16 @ 3-1/2" Length.(You want socket button head cap screws that take an allen approx $4.50 for all 3)
2 TB gaskets ($4 a peice at the local parts store)

Here is a pic of everything ... ignore the bolts i didnt end up using them:

Image

Information:

As stated above, i got the TB spacer from oletshot for a very inexpensive price .. couldnt pass it up.. Not much more explaination is needed. It has a 61 MM bore to match the TB that i also got from him (very good work).
The spacer however was all he provided, so i needed to figure out how to make it work.
I knew that when Steve (XJ-Armor) was around he sold a spacer with the bolts and the linkage all in one package which was great (i always thought his products were the bomb). So, amazingly, i did a search and was able to find one of his pages (i cant believe that there still up...just not the homepage anymore).
Here is the link:
http://www.xj-armor.com/tb_spacer.htm

That is where i got the idea for the linkage and the longer bolts.. (duh!)

So my only problem was trying to figure out how to make a longer linkage. I did a search on NAXJA, and found a thread about linkage for a TB spacer, but it was information for a 91+. I did however post in this thread asking for advice, and then was given a link to RUSTYS website. He sells a TB spacer here. I have no freaking clue how that linkage spacer in his product will work. It looks like what you would get with a spacer for the 91+ which WILL NOT work with the RENIX. I wonder if anyone has actually bought this?? I hope not!
Anyway, i was at the junkyard with a long time friend, and was telling him my plans. He without thinking said "take this linkage peice into work and have them extend it by an inch.. they should be able to do it really easily!". I thought DUH!. So i grabed the linkage and took it into work. Told the guys what i wanted and how i wanted it, and this is the result:

Each Side:
Image

Image

Smaller on top of larger:
Image

And side by side:
Image

They just used some solid rod, and welded it in where i told them to cut. You want the extension to be on that lower side (should be self explanitory). The pics above show what it looked like right after i had them do it.. I just used my grinding stone on my dremel to make it fairly smooth.

So after i had that done i went to Ace Hardware and picked up some bolts. At first i was after some of those socket head bolts like in the XJ-Armor pics, but they didnt have any that were that long, so i (not using my noggin) grabed some fully threaded hex bolts. Well to my suprise when i got home i realised they would not work! DUH Chris... the spot for the bolt is recessed into the TB.. no room for a socket wrench!!! What i needed was button head screws that were the proper length, but no one had any that were long enough! Fortunately i found a website that had what i needed. You can order them here (make sure you get 3-1/2" Length).

After you have these parts everything else should be self explanitory. Remove your old TB, and TB linkage. Clean up all gasket surfaces, and put down one gasket on the intake manifold. Set your shiny new spacer down, then put down the other gasket, and lastly your trusty TB. Use the new bolts that you got earlier, and tighten to 23ft #'s (per 1990 FSM). Now snap in the new linkage you made or had made for you, and plug everything else back in. Make sure you adjust your TPS you noob! And now enjoy!!

I hope all this helps someone!
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
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oletshot
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Re: Making a throttle body spacer work on a RENIX

Post by oletshot »

Nice write up. I like the solution for the linkage, simple. I would have made it much tougher on myself! It seems I'm good at finding the hard way to do things. :)
Oh yeah, do you feel it made a difference or did you put it on the same time as the 61mm TB?
I would have installed them seperately, refer to hard way statement earlier in post. :lol:
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Muad'Dib
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Re: Making a throttle body spacer work on a RENIX

Post by Muad'Dib »

oletshot wrote:Nice write up. I like the solution for the linkage, simple. I would have made it much tougher on myself! It seems I'm good at finding the hard way to do things. :)
Oh yeah, do you feel it made a difference or did you put it on the same time as the 61mm TB?
I would have installed them seperately, refer to hard way statement earlier in post. :lol:
Actually my initial plan was to install them at the same time, however i was not able to get the longer bolts locally, so i only have the tb installed for the time being. Its a huge difference with just the tb. I can barely press the gas pedal at a stop without jerking back with tons of torque. Best mod i've done so far.
The new bolts should be here soon so i can finally install it, and then let everyone know how i feel about it from a personal experience. I am not expecting any change.
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
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Re: Making a throttle body spacer work on a RENIX

Post by oletshot »

When I bolted it to my son's xj, told him take it for a ride, and saw the smile on his face when he returned, I knew it was a noticable difference.
He lives at home with us and was out with a friend one night and had to call me specifically to thank me for the TB. "Dad, thank you for boring out that throttle body! It's awesome!"
I told him those are brand new tires and looked at my wife who just rolled her eyes. :D :D :D
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Muad'Dib
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Re: Making a throttle body spacer work on a RENIX

Post by Muad'Dib »

lol ^^

As an update, i got my bolts today that i ordered:
Image
Image

There perfect. The head is exactly like OEM except they took a allen instead of a torx which was just fine. Fortunately i have a bunch of 1/4" allen bits. I'm not sure what the size of the allen actually is, but i do know it is between a 6mm and 7mm. Those ones i tried were labeled and the 7mm was too big. The one that i found that worked was not labeled.

Here is everything put together except for the intake tube:
Image

Image

Image

Initial tests are inconclusive. I just changed the oil pan gasket and oil pump over the weekend. Fixing those problems, doing some bolt tightening, removing all the tools that i have had in the back of the heep for awhile now.... etc... really made a performance difference. (Or its in my head).
Ill be able to tell in about a month wether it does anything as far as gas mileage. I doubt ill ever really know if it did anything for power.
I did find out however that the throttle linkage i had made was just slightly too short. No worries though, it just made the pedal a tad bit higher which i don't mind at all.
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
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Muad'Dib
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Posts: 1497
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Re: Making a throttle body spacer work on a RENIX

Post by Muad'Dib »

Ok, as an update here we go.

Throttle response has smoothed out from after i just installed the bored TB. This is a good thing in my opinion.... the throttle response was just too extreme. You couldnt press the gas without shooting out of your stop.

Gas mileage is still kind of up in the air in my opinion. I havent seen much if very little improvement. This could be because now i have changed my driving habits. It seems with the bored TB, and the spacer i dont have to give it as much gas to go (and i like to go fast) so... of course that would have a positive impact. So basically yes, overall i have seen an increase in mileage.
If it feels right, then STROKE it!
You're lucky that hundred shot of CAPS LOCK didn't blow the welds on the forum!!
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Shark
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Re: Making a throttle body spacer work on a RENIX

Post by Shark »

the throttle response increase i noticed after installing my 62mm TB on my HO was awesome. over time it has diminished. i once read that someone on naxja said this could be because the computer learns to compensate for the increase in air. not sure if that is true.
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Re: Making a throttle body spacer work on a RENIX

Post by seanyb505 »

Yeah but wouldnt more air mean that the computer would give more fuel?
Now I can be like all those other awesome people with more than one Jeep in their sig, but now I have to say one of them is sold:(
97 XJ 4.6
90 MJ 4.0 - sold

I want to have as many Jeeps as children. DD, offroader, drag MJ and another one. 4=4
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Re: Making a throttle body spacer work on a RENIX

Post by gradon »

Nah--you just got used to the extra power and are feigning for more.
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