im probably gonna lug the tbi and intake up to college one of these days to do a little machining. Just out of curiosuty, what is teh biggest bore on a stock tbi i can get away with doing? i was thinking maybe somewhere in the nehborhood of 48 mm or so.

 

Anyone?

 

go with 48mm, then you can use the stock TPI TB throttle blades. Thats what im going to do, i have a used TBI and some TPI throttle blades on there way and i cant wait to get started. Keep use all updated with the project. THANKS

 

Where is a good place to look for used 48mm tpi blades?

 

http://www.skulte.com/porting.html

This place bores out stock TPI TBs to 52mm so they probably have a lot of 48mm throttle blades sitting around. I emailed them the other day about selling me some of those blades. I also put some posts on these classified boards as well as the ones on 3rdgen.org and camaroz28.com, and within a day i got an email from a guy from camaroz28.com saying that he would be willing to sell me the throttle blades for 10 bucks shipped. So i think im just going to take those. hope this helps.

 

Read the BIG article Snf just posted about TBI's and you will learn all you need to know.

One more thing. BEFORE you bore the TBI out, turn it over and find the little ports that the evap canister vapors go thru. Follow the port on the front of the TB...see where the ports go up into the casting and then the little holes go out into the throttle bore? You need to machine some aluminum rods and cram them into the two ports that go up into the casting. If you don't you will be left with a gaping hole in the side of the bore.

take a look at mine
http://communities.msn.com/V8AstroCa...oto&PhotoID=90

http://communities.msn.com/V8AstroCa...oto&PhotoID=88

 

i read his article and what you said pritty much answered what i wanted to know.... I was just wondering what i would run into in the casting itself...

 

Over at the Crossfire forum, we are in the process of testing TB with 2.13" bores. These aew being built by our member Dan Plett and he is using sleeves. Anything more than a 2" bore will window the balancer port on the single bore TB's used on Xfire Vettes.

 

Here is a link for Crossfire 2.130 throttle bodies being tested now. Has anyone tried this with the 2 barrel throttle body housings?