tom i have seen in your posts that you have your throttle body bored out to 2.09".

i guess i can see how this is accomplished as far as the throttle body goes, but what the hell do you do for the throttle blades? they only really are a factor at idle..so did you just keep the stock ones and have a little extra air going into the engine at idle?

i saw your sig and got thinking about it. just wondering..

-Brian

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1991 Camaro RS
GMPP 350 HO crate engine - 454 TBI, MSD ignition, SLP exhaust, everything is new
700R4 - 2,400 stall converter, vette servo, shift kit
My car's webpage - z28boy.cz28.com
President - Central New York F-Body Association
Email - z28boy@twcny.rr.com
AIM - "Z28 Boy"

 

you need larger blades..theres a company that offeres them, but i cant recall the name

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1984 Z51 Auto, Ported and polished intake, K&N, MSD, Ram air/Cold air intake, no cat, no AIR, no egr, no swirls plates

 

Braswell carries them.

http://www.braswell.com/

More specifically

http://www.braswell.com/html/throttl..._base_pl.html#

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Dan

[This message has been edited by Lionsden (edited November 16, 2001).]

 

they wanted 40 bucks for 2 2.25" blades.

and they dont take credit cards.

they equip every nascar car with their carb and they dont take credit cards???? Well, thats what they told me anyway, i dont know if i beleive any of it.

 

I would like to know how you bored it also, I've got a spare TB laying around I'd like to play with. Also about what CFM do u think it flows now, and what is the maximum you can bore out the stock TB?

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89 RS parts car
Daily driver 91 RS auto LO3 70k, 14x3 K&N Open element, cat-back delete, Richmond 3.42's, Zexel Torsion posi, Accel remote mount Super Coil.
Coming soon: 470HP 383, Hooker SC/LT headers, Custom 4" exhaust, VAFPR.

 

cfi tb's can be bored out that much, but our sb 2bbls cant be. just to let people know. sbc tb's can only go to 48mm. i think that number is right. been a while since this topic came up.

 

Hey snuf, what about a 454 TB, how much can they be bored out?

------------------
89 RS parts car
Daily driver 91 RS auto LO3 70k, 14x3 K&N Open element, cat-back delete, Richmond 3.42's, Zexel Torsion posi, Accel remote mount Super Coil.
Coming soon: 470HP 383, Hooker SC/LT headers, Custom 4" exhaust, VAFPR.

 

not much more at all. but a little. i dont know if i would bother though. youve only got 4mm before you break thru the back or front wall of the bores to the outside of the tbi. i would worry about rigidity if you bored it out at all. the 454 is nearly impossible and worthless to want to mod, and you wouldnt really need to until really high hp applications.

 

Why do you feel it is nearly impossible & wothless to modify? I am doing a small cam 383 & with a bored & shaved SB TBI there is not enough air flow.

 

Sorry I haven't gotten back sooner. I got my plates from Braswell as Dan stated above. They cost me a whopping 12 bucks each. I bored the bodies using a boring bar meant for boring motorcyle/snowmobile cylinders. They came out beautifully. You also need to drill and tap new holes in the throttle shaft, since the holes in the plate are in a different location. Also, you need to grind the throttle shaft wider where the plate rests in the shaft. After I bored the bodies I nicely radiused the mouth into the bore like a velocity stack. It had this feature originally, but when you bore it, you leave a ridge where the bore job ends. Radiusing the bore-to-mouth grabbed me a whole 10th in the 1/4! Much to my surprise, so it is well worth doing.

I always wondered if people read my sig.

 

the 454 unit is large enough for most aps, not to worry about modifying, and the little that you COULD, wouldnt be worth much at all. the sb is worth modifying to the point you need the big block tb. Then after that, you will want to worry about either going to a holley 4bbl, or something with more cfm. This is one more reason i want to build my 2.25" 2bbl design ive made. 2bbls, more flow than the 454, less $$ than the 4bbl. i just dont have the prototype cash or means to make one on my own.