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Discussion Starter #1
i have a 5.2 and i came across some tips on how to bore and polish the tb.
well i did a great job of smoothing out and polishing and the performance gains are great

but it idles in park around 1400 rpms.

i tried to fab up some new butterflys that are a tad larger but it only made it wors.

im at a dead end. anyone know how to solve this?
 

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Discussion Starter #2
hey, i had to fab up some larger throttle plates. i did this with a brass sheet from home depot and my drelmell.

ill have to make another more refined set though.

brought the idle down to 900 rpms. this is better that 1500 rpms. ya think?
 

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It was really that noticeable as far as gains go?

I was on the dakota forum, and they recommend purchasing a junk yard TB to do this experiment on.

I'm actually pretty impressed that you were able to dremel a set out that improved things.
 

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Did you somehow alter the mounting position of the tps (throttle position sensor)? Just 1 degree of rotation could jump your idle my that much. I don't believe stock that they are adjustable but if all else fails, use a dremel or drill and elongate the tps sensor bolt holes and adjust it using a tach. Ideally you should use a volt meter not a tach and set it to about .7 volts as I recall. If you need the actual setting I can scan my with my snap on scanner and give you the exact voltage.
 

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Discussion Starter #5
no i didnt alter the tps at all. i bored out past the throttle blades thus making the stock blades too small and too much air was getting in. this caused the engine to idle high. do not bore past the blades unless you want alot more work for yourself!

i hit it right on the nose with the 3 rd set of blades. it took me 6 hours of meticulous grinding for those to fit perfect.

did it make a difference?

this mod works incredibly well with headers, intake, and free flow exhaust.
hell yes. no more dead spot on take off . on highway speeds it is very noticeable. just a tap on the throttle gives you much torque to the ground. almost too responsive.

when i put 31's on i lost alot of low end speed. now its back to hauling ass. it feels faster than when i had the 30's on.

a worth while free mod. i used this web site for instruction. and got the brake caliper honer from pepboys for 8 bucks.

i sanded until mirror finish was achieved then polished it with my dremell and some tripoli compound and then with mothers alluminum polish.

heres the site with the step by step instructions:
http://www.geocities.com/MotorCity/Garage/2566/

hey, you can do almost anything when you become completly obsessed!

i was on spring break so i took about 3 days to fine tune it. taking it on and off several times.

ill try and get some pics for you.

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<font size=-1>[ This Message was edited by: Bender on 2002-03-25 14:22 ]</font>
 

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Discussion Starter #7
fromwhat i understand , they do have the same tb's. the 318 and 360 block are the same size.

but its all said and done and in great working order.
 

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Discussion Starter #8
 

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i have a question.
were the plates round or did they have flats on them? the flats would be where they pivot. just wondering. i am thinking of boring my i6 TB out to 62mm but i will have to make a new plate too. thank goodness i work in a machine shop.
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Discussion Starter #11
where they pivot and are bolted into the shaft?

if this is what your asking then they are round. i am by no means a machinist and it took me 3 tries to get it just right with a dremmel.
 

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i read the page and i don't understand what that guy did to remove the most of the material. i thought i would just use the brake hone for the removal and boring of the throttle boddy but he said he used a grinding wheel?? i don't get it. i understand the sanding and the hone for polishing but the rest i am confised, do you think you could explain exactly what you did on yours? i have the 4.0L and i will be doing this soon aswell as port and polishing of the intake and exhaust.
 

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Discussion Starter #14
i got the dremmel out and ground and cut almost all of the air dam off. then i used a sanding attatchment on the surface. i switched to sand paper using finer and finer grit til i got to 600 afterwhich i polished it with mothers and tripoli compound.

you probably wont have to do the surface since you have the i6 right?


the cylinder hone will doo most of the work. might want to have a set of replacement pads for a second time. after your satisfied with the hone, go to the sand paper. the grinder is only for the air dams.

dont bore where the butterfly blades contact the wall unless you want to make your own. its a pain.
 

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save yourself time & patience? go to a local machine shop and have them do it. tell them 60mm diameter. especially if you've never done something like this before.

if you are going to do it, have a BIG can of WD-40. aluminum will load up any abrasive - big time!!.. liberal doses of WD-40 will help to keep that from happening.
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