OK, I am wondering if it would be a bit much for the mods that I have done to my car.

Here is basically what I have done to my engine:
Ported & polished Plenum, runners & intake base, 9.5:1 Compression, SLP Cam (Duration: 258/264 Dur @.050 206/212 Lift 480/487 centerline 112), SLP 1 3/4" headers, SLP Cat Back Exhaust.

Would the 52mm Throttlebody be too big. I am also considering a little shot of N0S.

any thoughts...

John


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87 Formula Yellow/Black

5.1 TPI Automatic
Baer 12" brakes 4 wheels, KYB AGX Adjustable Shocks & struts, Custom Leather interior, WAAAY TOO MANY MODS TO LIST

87 Formula TPI (5 Speed) Yellow/Gray STOCK

1967 Buick Riviera 430hp Turns high 14's (Not bad for 4300 lbs)

83 Camaro (Parts)
83 T/A (parts)

http://www.3rdgenformula.com

[This message has been edited by okfoz (edited September 17, 2001).]

 

Nah, the 52mm might give you the little help you are looking for, especially with that cam being a little better than the stock one. I say go for it if it's cost effective! Just don't forget to clean and reset the IAC and set your TPS voltage when you do.

Good Luck,
Brian P
89 IROC-Z 355

 

52mm will be too big.

Stay with the stock 48mm and use an airfoil.

 

I don't agree with it being too big. FWIW, I know someone using the 52mm TB on his 305 and it helped him out alot. He was using the L98 Camshaft, which is slightly smaller than your SLP cam, he had an AFPR(hope you got one of those by now!) and just recently added 24# injectors. While he did say that he cranked his stock 19lb injectors up to 49psi(that's where he was getting the best results) there were no vacuum or other issues to be noted.

52mm is okay, 58mm would be way too big for your application.

HTH,
Brian P
89 IROC-Z 355

 

It wouldn't be too big. That's like in that Car Craft 400 HP 305 buildup. They used a 750 cfm carb on a 305, despite the fact that every car guy on the planet would have advised against it. Was it streetable still? Yep. In fact, they said it was very streetable. The same would apply to a 52 mm throttle body over the 48. If your car has enough power, it's going to love the extra air.

Jon

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89 GTA
Beautiful Gunmetal gray, LB9 305 and T5 tranny. Only 60,000 miles!
Dual cats, 3"flomaster
Accel 300+ Ignition, wires, cap, coil, etc
Airfoil
KN Airfilter
Removed Screens on MAF
SLP 1 3/4 headers
No Smog/AIR system

 

It will work fine for you, there is no such thing as too much TB. Increased TB size does not have the same stigma as running too large a carb. The TB just lets air into the plenum. There are no velocity issues, nor are there fuel mixing distribution issues either.

The better question is, is it worth it. It seems to me that you are still running stock heads. That alone tells me that you are nowhere near needing a bigger TB. You'd be much better served to put the money for a TB into something you could use.

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Ed Maher - Moderator @ The TPI & Carb Boards
92 Z28 Convertible - Quasar blue / Tan top
305 TPI A4 2.73 - 14.8 @ 93.1
Stock except ported plenum and dual cats
-=ICON Motorsports=-

- Definitely prototypes, high powered mutants of some kind. Too weird to live, too cool to die

 

ok, I guess that makes sence. I enentually wish to go to a 350 or 383 and go Vortech, I know that is a dirty word around here, but there are alot of guys here using the vortech heads for roun-d-round racing.

thanks

John

 

The 52mm TB will be fine. I've been running one on my IROC for 4yrs now and it's very streetable and did well at the strip.

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1986 IROCZ-28 Site
Best Times:
60'=1.92sec, 1/4mi=14.42sec @93.99mph in 65deg temp

 

52 is over kill, get the 50

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- David
88' GTA 5.7L TPI MODS---> air foil, K&N, Shift Kit, 180* therm, TB bypass, Gutted CAT, Flowmaster 80 Series

 

Who makes a 50mm throttle body???

That is a new one on me.