im trying to cheaply make a 60mm tb for my 3.4 pr. should i use a 3400 tb? my trueleo uses the stock fiero style bolt pattern.

a 3800TB would suit your needs here, stock they are just slightly larger than 60mm, I think around 64-65?

i talked to orief about it and 62 is the biggest size for a 3.4 w ported heads and 60 for unported would be good to 6k. 64-65 would be a lil too big, my main goal is to get everything correct with nothing to big or too small.

perhaps a certian year 3800 would have a smaller size?

I don't know about the bolt pattern, but I know that a Quad4 (not 2.4 TwinCam) throttle body starts out at 56mm (Probably just the HO q4s at that), and can be bored to 60. I happen to have one of those in my basement actually. Mine is the 56. No provision for Cruise Control if you actually care.

Well your going to be making an adapter plate, so technically you could make it a restricter plate too? I dont know what it would mean to have it worked out like that, but you could dial the size down from a bigger TB.

edit

I think its more like 69mm, so no, I wouldnt start here lol.

[This message has been edited by darkhorizon (edited 10-29-2007).]

well i did some searching on the forum, had to use the entire post search but things r slow today, seems a gn throttle body is 59mm and can be adapted and an early dohc is 62 . the port opening in my intake is 61 so some minor grinding will work that out if i do go 62 but thats 2mm larger than i need. lookin for a 6k peak power which orief says is a 60mm tb, and of course a good cam for that.

i looked up the gn throttles and it seems some had 4 bolts and some had 2 bolts holding them down but there is a guy (the half shaft mod) guy who does these, if a gn tb is 59mm ill go for that as is. i shot him an e-mail, if anyone has a gn throttle body laying around it would be nice to know if it bolts up or not and if the sensors work.

from searching the forums it seems nobody has addressed where you get the correct throttle body for a 3.4 once you get a good intake on it, hopefully this will help in locating the right one.

[This message has been edited by megafreakindeth (edited 10-29-2007).]

You could use a GN TB (3.8 turbo) it's 59mm and can be bored to 65mm or 60mm if you like.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

does the gn tb bolt right up? are the sensors and cable orientation correct?

GN TB bolt pattern is different. Butterfly opening is the opposite. Sensors use the same plugs as Fieros. If your having this made by FrancisT he should have the pattern, he made mine.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

problem is the intake has been made. though i have no problem making a flange or adapter i got a good tig welder at work he used to weld cruise missle tubes into subs this will take him about ten seconds. wait and see if anyone else has any input then ill probably go with the gn tb.