i dont wanna buy it if itll be a waste of $$
i have a gutted maf on the way no fins no screens whatcha think mods im my sig

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1992 camaro RS
195cc AFR heads with compition port work milled to 58cc
373 10 bolt rearend
ssm sfc's
87 350 TPI
bored 30 over
compucam 2032 with 1.65 full roller rockers
497-510 LIFT 214-220 duration
msd6AL
1 5/8 headman headers
2 `1/2 flowmaster exuast
k&n filters gutter air box gutted maf
3 pc under drive pulleys
no emissions no egr etc
custom ED Wright chip
eddelbroc intake base and runners ported plenum
Taylor 8mm wires
B&M mega shifter
gutted maf/airbox
hotchkis lower control arms
3" exhuast cutout
homemade cold air intake
2000 tci stall
700R4 with B&M shift kit edelbrock water pump
new best ET 13.5 @104.66
no times with new afr heads hopeing for 12's

 

Simply put.... HELL YES YOU NEED IT. Do you think that the stock TB is going into the 12's? Nope

 

thats what i thought but heard gm is useing 48mm throttle body on a 500hp crate motor

 

the bigger throttle body shouldn't hurt you at all and may help some.
Yes you can go 12's or 11's or whatever you want with the stock throttle body. Whoever thinks you can't just doesn't understand airflow.
Just don't spend a lot of money on a TB because it's not really worth it.

ODB

 

u think a 58mm is to big for me?

 

There's no such thing as too big. You just have to have the ECM programmed to match the airflow when you open the throttle, otherwise you could have a stumble or flat spot.
There's also no promise that a larger TB will make you any faster.

 

maybe someone who reads this can verify what I am about to suggest. I dont know if this is true or not but I have thought about it and have figured this much anyway.
ok, so you want a bigger TB, well there is only one real benifit you can see by going to a bigger one.
that is that your old one is not flowing enough to meet your engines demands.
this is the old kink in the garden hose theory.

the thing that I have come up with will tell you if you really need a new one.
I notice that my tpi (a 305) pulls harder and harder with the more pedal I give it --- to a point! --- after I reach about 80 - 90 percent throtle all the extra pedal does is make the tranny hold the gear longer.

now by assuming that the TPS has signaled for WOT before I reach this "wall" i am describing, we can extrapolate from this that once that certain percent of the throtle body is opened, and then exceeded, some other part of the intake system BECOMES the throtle (i.e. some other part of the intake is a bigger restriction than my partially open TB)
so this tells me that untill I find the other restrictions that limit or "THROTLE" the engine the stock TB is big enough and flows more than that other restriction in the intake.

I understand that this simplified discussion does not include rpm considerations. but I think that if I did this kind of test at the strip and fixed the tranny shift points or shifted manually at the same points, then I could acheive simmilar timeslips with ANY percent of throtle application above the "wall" or intake tract throtle. once I had reached the ultimate flow limit of the intake (at whatever rpm it occured) torque would level off and times would too. if times got better and better right up to 100 percent throtle, only then would I really consider the TB to be a "restriction", and accordingly try a bigger one until times started leveling out.
i dont think you really need a strip to do this though.
just find somewhere you can punch second gear safely and put your tranny in second.
then do a series of "runs" at varying pedal positions. idealy you would want every one of these runs to be with the ECM in WOT mode just to make things even, but I think checking that your TPS is over 4 volts at like 75-85% throtle should do it.
start from that % throtle on your runs and once you feel that the car doesent respond to any more pedal then you know your TB is big enough.

whew!

1000 apologies for the long post but I figured I had to write this stuff in an aplicable topic.

all in all I think looking at your mods a 52 would help, but you might want to listen and see if someone thinks my idea is a good one.
if not please disregard and call me an idiot.

good luck



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88 WS6 T/A 305 TPI--
K&N,Air foil,hypertech chip, thermostat+fanswitch
free mods, dynomax catback, urethane motor+trans mounts,
SSM SFCs, Bilsteins
very trick homemade ramair, Accel 300+ ignition system.
Planning: hedman 1-5/8 longtubes, NOS 150 plate, world 305 heads, replace the "peanut"! and other susp. mods.
check it out at:
http://www.geocities.com/transam617

 

Yes, like ODB said, u can run 12's on the stock 48mm TB. But if u went to a 52 or 58, u would probably run even better than with a 48. It would also be good for even heavier mods that u might want to do. When u are running 11's and 12's, the 48mm TB will probably be a restriction for a high flowing 350 running those times.

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Looking For:

87 IROC-Z 350 TPI
84 TRANS AM 305 H.O.

[This message has been edited by IROCZTWENTYGR8 (edited February 16, 2001).]