I'm about to order a new throttle body and was wondering if I should just buy a 58mm one instead of a 52mm one because they are only about $20 different in price. What do you think? I'm not sure if I'll ever need the 58 but it's only a little more. It wouldn't hurt performance any, would it?? Also, can the plennum be ported enough to match a 58?


Thanks for the time

Rob

------------------
1987 IROC-Z Auto (LB9)
Black/grey with the stance of a streetfighter

Mods
Custom exhaust. 4 Inch pipe from the headders all the way back to a single muffler at the rear. No Cat.

Future mods:
K&Ns
RAM Air
New Underdrive pulleys-either March performance pulleys or Auto Specialties Performance
Air foil

 

Why spend all that on a TB when u could get other things that would give your car more HP?? The TB doesn't restrict as much as u think, especially for a 305. There are cars making more than 500HP with a 48mm TB, and they are 350's.

https://www.thirdgen.org/messgboard/...ML/001210.html
https://www.thirdgen.org/messgboard/...ML/001112.html


------------------
Looking For:

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

[This message has been edited by IROCZTWENTYGR8 (edited February 08, 2001).]

 

If you want to kill power, sure go get the 58.
I see from your sig you have an 87 with exhaust. An airfoil is probably your best bet, followed up by the 52 if you plan on porting and a cam in the near future. The 58 on a 305... well, a 305 that would need that you would not want to drive on the street.

 

a 58mm TB will kill your air flow velocity. your cylinders will not fill up as well as they could and you will lose power even a 52 is too big for a stock intake 305 IMO

 

I agree with the others, you are not anywhere near needing a TB yet, you would be better served to spend your money elsewhere.
And i'd love to hear an explanation from 88 on how a 58mm TB will hurt velocity and torque.
...ed

------------------
Ed Maher - Moderator @ The Carb Board
92 Z28 Convertible - Quasar blue / Tan top
LB9 4L60 GU2 G80 - stock, soon to be sleeper

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

 

He's right the 58 mm will hurt him. 58mm tb's are for cars in the low 12's high 11's. 52 is fine for mid high 12's-high 13's. other than that the stock is fine.

------------------
SUPERCHARGED 87 GTA: Blk/Gld w/Superam, 355cid Trickflows, forged pistons 9.5:1. Auto 2,600 stall, 3.45 9 bolt disc, Best time & mph (Naturally Aspirated): 13.567 @ 101.900 w/ a poor 60ft. Best mph: 104.3 *This car is 100% NYS emissions legal, w/ all emissions controls!* "If you want to have a fast car, hang out w/ those who do!"
http:// www.community.webtv.net/munks87/JustinsGTApage.com
VORTECH S-TRIM, INSTALLATION IN PROGRESS: 10 & 15 LB> PULLEYS, CUSTOM HKS RACE BYPASS, CUSTOM DUCTING W/ COLD AIR, SWAPPING TO SERPENTINE, & MANY EXTRAS! BEST TIME: 11'S I GUESS. WE'LL SEE IN SPRING!

 

To make you feel better, GM has a 48mm t-body on the ramjet 502 that makes 500+ horsepower. I'd spend that 300 bucks on something else!

------------------
'87GTA w/ SLP Cold Air, MSD Coil, Airfoil, Gutted MAF, AFPR, TES Headers, HI-FLOW CAT, Flowmaster Catback, Energy Suspension Master Bushing Kit

 

Your car would get better results just by porting the plenum, airfoil, and airbox mods.

------------------
Looking For:

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

 

I'm waiting for my AFPR, K&Ns and my RAM AIR to come through. I'll be porting the plennum and gasket matching everything too. As I'm getting a cam change in the summer I figured it would be better to get a 52mm throttle body than just the air foil.

 

No, just get the airfoil, its a 305 not a 383. U could spend that money on things that would actually make your car faster.

------------------
Looking For:

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

[This message has been edited by IROCZTWENTYGR8 (edited February 09, 2001).]