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What is stock fuel pressure and what is good for max HP??

  • Thread starter Thread starter Kdubslugga
  • Start date Start date Aug 19, 2005

Kdubslugga

Active Member
Jun 7, 2003
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38
Akron, OH
Aug 19, 2005
#1
  • Aug 19, 2005
  • #1
I just got a Fuel Pressure guage and it reads about 33 psi warmed up. Im assuming this is rather low??? What should my pressure be?? This winter im installing a Fuel Pressure Regulator and a new 155 lph fuel pump. I want to get max HP out of it so whats the best PSI to set it at???
 
D

Daggar

New Member
Jul 19, 2004
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0
Aug 19, 2005
#2
  • Aug 19, 2005
  • #2
It's not a question of what is the optimum fuel pressure but rather what fuel pressure is required for optimum Air fuel Ratio on your particular combination. Normally aspirated with stock compression, a good AFR window would be somewhere between 13 to 14:1 at WOT. Blown apps will be richer (about 12.5:1). Put it on a dyno with a sniffer up the pipe and tune your fuel pressure for whatever your car likes best to make power.

Edit: And Welcome back Kdub... haven't seen you in a while.
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
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129
Aug 19, 2005
#3
  • Aug 19, 2005
  • #3
If you read 33 PSI wiht the vac line attached the to reg, that is just right. This should correlate to around 38-39 PSI with the line off and capped.

Remember, as long as you dont run out of pressure at WOT, the puter can adapt a bit around the pressure you set, by increasing or decreasing the injector pulsewidth.

Good luck.
 

Kdubslugga

Active Member
Jun 7, 2003
1,515
3
38
Akron, OH
Aug 19, 2005
#4
  • Aug 19, 2005
  • #4
Thanks Daggar, ive been around, ive mainly been posting on Talk though!
 

mustangGT85

Founding Member
Aug 16, 2002
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0
Orange CA
Aug 20, 2005
#5
  • Aug 20, 2005
  • #5
so stock PSI should be around 40psi?
 

HISSIN50

"How long does it take to get help in here?
15 Year Member
Nov 29, 1999
31,179
34
129
Aug 20, 2005
#6
  • Aug 20, 2005
  • #6
mustangGT85 said:
so stock PSI should be around 40psi?
Click to expand...
Stock spec is 38-39 PSI with the vac line off and capped. With the line on (as it is normally), anything over 30 PSI is ok, but most see 32-33 PSI.
 
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