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AFPR SETTING

Old Apr 15, 2007 | 10:54 AM
  #1  
1987ZTPI's Avatar
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From: SOUTHERN ALBERTA
Car: 1987 IROC-Z
Engine: 310 lb9
Transmission: SEMI STOCK 700R4
Axle/Gears: 3.45 9 BOLT
AFPR SETTING

I just installed an AFPR i was running 40psi at idle and 45 when i disconnected the vacum line i'm told that stock pressure at idle should be 42-43 psi , i have a bunch of bolt on headers wires , pullies full exhaust , also msd 6a and coil as well as a programed E-PROM , tb air foil and port and polish on the upper plenum and runners . what is a good pressure to start off at i've been told that 46psi at idle will give you better performance even on a stock motor any input would help thanks

RYAN
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Old Apr 15, 2007 | 11:05 AM
  #2  
DJP87Z28's Avatar
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From: Florida
Car: 1987 Black IROC-Z (SOLD)
Re: AFPR SETTING

Stock fuel pressure at Idle shpuld be 36/38 PSI. Why do you think increase pressure at "IDLE" is going to increase your performance??
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Old Apr 15, 2007 | 11:05 AM
  #3  
Reid Fleming's Avatar
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From: Houston, TX
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: AFPR SETTING

5 psi difference when pulling the vacumme line? Mine was 43 psi with line on or off. In fact it's never made a difference for my car whether the line was on or off.

I upped mine to 50 psi and it seemed to have better throttle response. Better midrange power.
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Old Apr 15, 2007 | 11:06 AM
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Dyno Don's Avatar
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From: Orange, CA
Car: '90 Trans Am-12.45@110.71
Engine: 355 w/AFR 195's Elem. 400/430 HP/TQ
Transmission: Tremec T-56
Axle/Gears: 12 Bolt 3.73
Re: AFPR SETTING

Pressure at idle should be 42-43 psi with the vacuum line off. 37-38 w/it on.
Unless you do a custom chip, that is where it should be.
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Old Apr 15, 2007 | 12:21 PM
  #5  
1987ZTPI's Avatar
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From: SOUTHERN ALBERTA
Car: 1987 IROC-Z
Engine: 310 lb9
Transmission: SEMI STOCK 700R4
Axle/Gears: 3.45 9 BOLT
Re: AFPR SETTING

well not sure about everything i'm hearing cuz with the pressure at 49psi at wot and 44 at idle the car runs alot better it idles way smoother it idles at 650rpm and it just feels smoother it kind of feels the same or a tad slower than befor when accelerating but that mite be because it's 2 degrees outside but it feels alot better to me.

AND I DO HAVE A CUSTOM BURNED CHIP
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Old Apr 15, 2007 | 06:46 PM
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Dyno Don's Avatar
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From: Orange, CA
Car: '90 Trans Am-12.45@110.71
Engine: 355 w/AFR 195's Elem. 400/430 HP/TQ
Transmission: Tremec T-56
Axle/Gears: 12 Bolt 3.73
Re: AFPR SETTING

Was it burned for 49 psi @ WOT?
It so, that's why it runs better there.
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Old Apr 15, 2007 | 08:46 PM
  #7  
1987ZTPI's Avatar
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Joined: Feb 2007
Posts: 141
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From: SOUTHERN ALBERTA
Car: 1987 IROC-Z
Engine: 310 lb9
Transmission: SEMI STOCK 700R4
Axle/Gears: 3.45 9 BOLT
Re: AFPR SETTING

not sure if it was programed for that pressure , when i gave the guy my mods lisy he said i should put in a 165 degree thermostat and maybe an adjustable fuel pressure regulator to help tune it better .
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