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Throttle Body

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Old Apr 12, 2011 | 07:49 PM
  #1  
lb9 GTA's Avatar
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From: Toronto
Car: '88 Trans Am GTA
Engine: 305 TPI
Transmission: 700R4
Throttle Body

I've been dealing with an intermittant code 34 for a while now and, after reading the article that formulax4 posted I read that a worn throttle body could be the problem. I went out and tested the TB and sure enough it's worn out. So I'm wondering what the best TB would be for my car. It's completly stock aside from a cat back and CAI for now. I know I won't see any benifits from going with a 52mm now but I do plan on up grading in a couple of years where it may make a difference. Anyway, suggestions and insite would be appriciated.
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Old Apr 12, 2011 | 09:44 PM
  #2  
james.gould150's Avatar
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Joined: Mar 2011
Posts: 183
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From: Mays Landing, NJ
Car: 1991 z28
Engine: 305 tpi
Transmission: 700r Automatic
Re: Throttle Body

i am subscribing not stealing your thread id like to know too i want to upgrade my tb as well but and reluctant to but the 52mm one but idk if ill even see performance
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Old Apr 13, 2011 | 01:05 PM
  #3  
lb9 GTA's Avatar
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From: Toronto
Car: '88 Trans Am GTA
Engine: 305 TPI
Transmission: 700R4
Re: Throttle Body

I know I won't with the way my car is now. My cam is too small and my heads and intake are too restrictive to see any improvement in performance.
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Old Apr 13, 2011 | 01:15 PM
  #4  
vette_1989's Avatar
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Joined: Aug 2007
Posts: 49
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From: Michigan
Car: 1987 Silver IROC-Z
Engine: 305 V-8 300HP LT1 Cam
Transmission: T-5 5-speed
Axle/Gears: 3.42
Re: Throttle Body

Everything that I have read is that the stock 48mm TB will support up to 500HP. So don't think that big is better.

Originally Posted by lb9 GTA
I know I won't with the way my car is now. My cam is too small and my heads and intake are too restrictive to see any improvement in performance.
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Old Apr 13, 2011 | 02:32 PM
  #5  
myzblubyu's Avatar
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Joined: Sep 2009
Posts: 95
Likes: 3
From: Virginia
Car: 1990 Iroc, 1984 Buick Regal
Engine: 5.7, ZZ4 crate w/FIRST injection
Transmission: 700r4, 700r4
Axle/Gears: 3.73, 4.11
Re: Throttle Body

BBk or Holley 52mm... If you need another TB let me know I have 3 stock ones laying around...
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Old Apr 14, 2011 | 11:09 AM
  #6  
lb9 GTA's Avatar
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Joined: Dec 2009
Posts: 517
Likes: 1
From: Toronto
Car: '88 Trans Am GTA
Engine: 305 TPI
Transmission: 700R4
Re: Throttle Body

I've desided to get my stocker rebuilt locally
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Old Apr 15, 2011 | 12:19 PM
  #7  
Chevy86 IROC-Z's Avatar
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From: Far West
Car: 1986 Camaro Z28 IROC-Z
Engine: 350 Tuned Port Injection, for now.
Transmission: 700R4
Axle/Gears: Posi - 3.23
Re: Throttle Body

If you plan on getting the larger TB (58mm), you wont see any difference. You need to port the plenum, get larger runners (edelbrock,Arizona Speed and Marine, Accel), and a Edelbrock intake manifold. New Aluminum heads would also benefit this combo. If you get just the TB and use the stock intake, the incoming air will be too restricted and itll defeat the purpose of a TB upgrade. I have my stock TB on right now. I got the Edelbrock Hi-Flow base aswell as a few more aftermarket parts just laying around in my computer room. No sense installing them just yet because i dont have all the parts necessary to make my baby tear up the rear tires.
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Old Apr 15, 2011 | 02:31 PM
  #8  
james.gould150's Avatar
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Joined: Mar 2011
Posts: 183
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From: Mays Landing, NJ
Car: 1991 z28
Engine: 305 tpi
Transmission: 700r Automatic
Re: Throttle Body

is it worth it to get just the runners and the tb? or is it the same deal and i should wait until i can afford the intake to?
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Old Apr 16, 2011 | 02:20 PM
  #9  
Chevy86 IROC-Z's Avatar
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Joined: May 2009
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From: Far West
Car: 1986 Camaro Z28 IROC-Z
Engine: 350 Tuned Port Injection, for now.
Transmission: 700R4
Axle/Gears: Posi - 3.23
Re: Throttle Body

Its best to wait and buy it one at a time especially if your tight on a budget. but to really FEEL a big difference, here is what I suggest. These changes will give you around 5-30 hp more depending on which items you choose. Here we go.
1. roller rockers, roller lifters (roller lifters will only work if you have a roller camshaft)
2. ported plenum
3. Air box filter bottoms removed
4. after market runners, aftermarket intake manifold
5. aftermarket aluminum heads ( better perfomance if heads are port and polished)
6. aftermarket headers and y-pipe
7. 52 mm TB (Holley) with TB Airfoil
8. MAF Sensor screens removed

these mods will increase power to the rear wheels and there is no need to reprogramm the MemCal (PROM). Also if you choose to buy a roller camshaft, make sure the camshaft is "Computer Controlled". If it aint "Computer Controlled," YOU WILL lose vacuum and you WILL have serious issues. This suggestion of mods is what I have done and will do to my 86 TPI IROC-Z. Like I said, buy the parts (runners and intake manifold) one at a time so that you can remove all the parts at one time instead of once every 3 months. You can choose to put on the TB though since it is easily accesable. Good Luck man
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