bad camaro RS

or a waste of cash?

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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

IROCZTWENTYGR8

iTrader: (1)

With your mods, especially with the heads and cam u have, I would say yes. Your engine is a high flowing 350 that wants even more flow, and the TB will give that when u have the kind of mods that u do. U might even want to go with a 58mm.

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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 15, 2001).]

88305tpiT/A

iTrader: (2)

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

IROCZTWENTYGR8

iTrader: (1)

His car will be in the 12's. He has 195cc heads and a cam. The engine will need more airflow if he wants better results. U will be able to go 12's with the 48mm, but your times will probably be better with a 52mm or 58mm TB. Can't guarentee that it will though.

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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).]

MadMax350

The question you need to ask yourself is what your engine actually requires in terms of airflow. There is a simple fomula for this : Cubic Inch Displacement (CID) x maximum RPM divided by 3456. So, if you had a 350 ci engine, the most air it could want at 6500 RPM is 658.3 CFM. This is assuming a volumetric efficientcy of 100% (which is hard to attain, especially at max rpm). Do you really need a bigger throttle body? Probably not. I recently flowed a stock 48mm throttle body without an airfoil and got 783 CFM out of it. (for more details, check out my flow test page at http://dtcc.cz28.com/flow/index.htm )
Does this mean your engine doesn't need a bigger throttle body? Maybe not. You have to remember that a flow bench provides a constant vacuum source, not like an engine at all. An engine depends on velocity as well as raw airflow. I have seen many stock TPI's get about .2 seconds faster with a 52mm vs. a 48mm, and have seen an LT4 go slower with a 52mm vs. a 48mm. Likewise, I have seen a 350 TPI go .5 seconds slower by going to a 58mm from a 52mm.
Basically what this means is that for the money it probably isn't worth it. My advice to you is see if you can borrow a 52 from a friend and do your own tests on your car to see if you actually gain anything before forking over some $300+ for an aftermarket throttle body.

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1987 Trans Am GTA WS6
-5.7L SuperRam
-TFS Twisted Wedge Heads
-LT4 HOTCAM
-LT1 PM Rods
-380 HP @ 5000 (net)
-442 TQ @ 4100 (net)
-4L60-E Transmission
-LS1 Aluminum Driveshaft
-4.10 SRD

1988 Pontiac Grand Am
-3800 SFI V6
-125-C Trans
-Stock 2.5L converter (stalls at about 3000)
-Stock emissions equipment
Domestic Terrors Car Club Online

vortech305

Whatever u do dont put a 58mm throttle bodie use a 52mm, 58 or for cars with 383's or 406's if your car has a supercharger use a 58 otherwise stick with the 52.


But hey thats my opinion

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92' camaro
New 305 block TPI conversion, Forged parts all around,Edelbrock intake,ported plennum,ported corvette alluminum heads accel cam,52mm throttle bodie, SLP runners,ford SVO 19lb injectors,fuel regulator,cloys timing chain, comp alluminum roller rocker arms and pushrods msd 8.5 mm wires hypertech coil and plug, Edelbrock TES headers, free flowing catalytic converter and a 3 ich force II flowmaster exhaust system.
Soon to come!!!
Procharger system 12lbs o boost.
Favorite quote: "where ever u go, there u are"

steve8586iroc

I thought the maf was a bigger restriction than the tb or am I wrong? I would think about a Wells maf along with a 52mm tb. It would be nice if a friend had both and would let you test with them.

Thats my .02 worth.

Dan87IROC-Z

I dunno if I'd go as big as a 58mm, but I do think a 52mm maybe a little too small with all of your mods. I think that AS&M carried a 54mm TB, that would work great for your car.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End

Current Mods: LT4 Hot Cam, Comp Cams 1.52:1 Roller Rocker Arms, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

7.5" 10 Bolt with 3.42s soon to come!