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View Full Version : recommended fuel pressure for a Holley?


04ctd
05-28-2010, 10:46 AM
have a Holley HP 4150 on there, 950.

has a gauge, been running about 5.

moved the regulator around (moved fuel lines from wheel well area, that won't pass NHRA tech, i was told)

and noticed it was about 7 or 8 now, guess i nudged it.

does it really matter at all?

WWhittle
05-28-2010, 01:36 PM
Of course it matters! That's your tune up! That is like saying that you accidently bumped your timing up to 60 degrees and asking if it matters.
(Not trying to be a smartass)

04ctd
05-28-2010, 02:07 PM
Your carburetor requires 4 to 7 psi of fuel supply at all times, under all conditions.

http://www.bob2000.com/carb.htm

WWhittle
05-28-2010, 02:11 PM
Your carburetor requires 4 to 7 psi of fuel supply at all times, under all conditions.

http://www.bob2000.com/carb.htm

I'm not reading all that.

4 pounds of fuel pressure and 7 pounds of fuel pressure are completely different tuneups.

If your car was tuned up on 5 pounds of pressure, and you now have 7-8, it is a different tune up, there is no doubt about it.

And actually, 5 pounds and 5 1/2 pounds are a substantially different tuneup. If your car has never had a precise tuneup to begin with, then it probably doesn't matter, but that is a whole different issue.