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Adjustable Fuel Pressure Regulator

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Old Jul 20, 2005 | 09:59 PM
  #1  
Cdn Chopper's Avatar
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From: Ontario
Car: 91 GTA
Engine: 5.7
Transmission: 700r4
Adjustable Fuel Pressure Regulator

I have read that going from stock fuel pressure to around 48 or 50 lbs. will give you a nice little bump in HP. at wot. Can any one verify this?
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Old Jul 20, 2005 | 10:34 PM
  #2  
boussole's Avatar
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From: Gatineau,Québec, Canada
Car: 91 ws6
Engine: ENGINE, GAS, 8 CYL, 5.0L, TPI, HO
Transmission: TRANSMISSION, MAN 5 SPD, B0RG WARNE
Axle/Gears: AXLE REAR, 3.42 RATIO
good ?

what is the procedure to do this on tpi
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Old Jul 21, 2005 | 12:14 AM
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WhiteKnight's Avatar
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Car: 88 GTA
Engine: 305
Transmission: Manual
the procedure? Buy yourself an adjustable fuel pressure regulator and install it. You'll need a guage to check pressure for when you install and tune it. I have the Holley regulator. It more expensive than the others, but its really nice.
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Old Jul 21, 2005 | 12:41 AM
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
^ any fitment issues with the plenum?
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Old Jul 21, 2005 | 12:17 PM
  #5  
twobirds's Avatar
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From: Thornton, CO
Car: 1987 GTA 350
Engine: L98
Transmission: 700R4/2400 stall
Axle/Gears: B/W 3:27 posi disc
No fitment issues with mine(I have the Holley also).

Conrad
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Old Jul 21, 2005 | 04:09 PM
  #6  
Cdn Chopper's Avatar
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From: Ontario
Car: 91 GTA
Engine: 5.7
Transmission: 700r4
But what about the HP gain, if any
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Old Jul 21, 2005 | 04:43 PM
  #7  
87TPI350KID's Avatar
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Car: 1987 IROC-Z Camaro
Engine: 5.7 350 TPI - SLP Runners, AFPR, MSD Goodies
Transmission: 700R4 - Shift Kit, Corvette Servo
Axle/Gears: BW 9 bolt, 3.27s
.

Horsepower? Maybe 5 or so, but you can adjust your air/fuel mixture to make more power. Also a little flatter power curve. Ive seen them take .1 seconds off a 1/4 et when adjusted right.
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Old Jul 21, 2005 | 09:48 PM
  #8  
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From: Waynesville,Ohio
Car: 1989 Trans Am
Engine: 350 TPI
Transmission: 700R
Axle/Gears: 9 bolt 2.77
More Fuel

I just added A BBK FPR and BBK fuel Pump and I think I have bigger injectors on my 350 TPI car. I run a little more than 50psi and although my old fuel pump was weak it took me 2 a 15.0 quarter mile.,and now I can notice a big difference after I installed those parts + some headers.
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Old Jul 25, 2005 | 12:02 PM
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Rob Wade's Avatar
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From: Windsor Ontario Canada
Car: 89 jaguar xjs convertable
Engine: 89 L98 5.7 TPI
Transmission: 700R4
Axle/Gears: 3.23 dana 44
Carefull not to run to much fuel pressure. You will dramatically shorten the life of your injectors due to the added stress of the injector trying to close against the higher that stock fuel pressure!
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Old Jul 25, 2005 | 10:31 PM
  #10  
Cdn Chopper's Avatar
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From: Ontario
Car: 91 GTA
Engine: 5.7
Transmission: 700r4
I can't remember where I saw it, but there was an independent dyno run made with a stock 5.7 tpi. The HP gains were substantial. Something like 20 or 30 hp. Apparently the fuel atomizes better at higher pressure causing a faster and cleaner burn. Sounds reasonable. If I come across the dyno stats again, I will post it.
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Old Jul 29, 2005 | 08:04 PM
  #11  
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Car: 1987 IROC-Z Camaro
Engine: 5.7 350 TPI - SLP Runners, AFPR, MSD Goodies
Transmission: 700R4 - Shift Kit, Corvette Servo
Axle/Gears: BW 9 bolt, 3.27s
.

Originally posted by Cdn Chopper
I can't remember where I saw it, but there was an independent dyno run made with a stock 5.7 tpi. The HP gains were substantial. Something like 20 or 30 hp. Apparently the fuel atomizes better at higher pressure causing a faster and cleaner burn. Sounds reasonable. If I come across the dyno stats again, I will post it.
As much as I would like to belive it, I don't think it does. Couple of ponies at its best, but where it comes in handy is when you get better parts, you can tune the fuel pressure to make substantial power.
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Old Jul 29, 2005 | 08:29 PM
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From: columbus, in.
Car: 1989 pontiac firebird trans am gta
Engine: 355
Transmission: 700r4
Axle/Gears: 327:1 9 bolt
I knocked .24 secs off of my 1/8 mile time with a bbk regulator. I have pressure set at 48 psi. I did have a small fitting problem though. The bolt is to long and actually can not go any lower then 48 psi because it hits the plenum.
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Old Jul 29, 2005 | 08:42 PM
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From: Brooklyn NY
Car: 1985 iroc
Engine: 5.0
Transmission: auto
Since we are on the regulator, how do you know if you have a bad one? Also, what is the stock PSI on an 85 305? What would be the max that the stock injectors could handle?
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Old Jul 30, 2005 | 03:14 PM
  #14  
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From: Sioux Falls,SD
Car: 1985 Z28 Camaro
Engine: 5.0 TPI
Transmission: 700R-4
Axle/Gears: Posi Richmond 3.73
Not sure what the stock setting is, I think 42 psi. I have a Jet AFPR bumped up to 50 psi. I noticed a small increase in power, but I am using stock 19 lb injectors and modified exhaust manifolds. Next weekend I'm putting 22 lb injectors in so hopefully I'll get a little more hp.
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Old Jul 30, 2005 | 03:46 PM
  #15  
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From: columbus, in.
Car: 1989 pontiac firebird trans am gta
Engine: 355
Transmission: 700r4
Axle/Gears: 327:1 9 bolt
I know it is 42 psi on a 350 but I am not sure on a 305.
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