Free Fuel Pressure Increase Modification

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modification was performed on an 87 Vette with approx. 100K on the
odometer, a gutted MAF, a K & N air filter, Jacobs 8.5mm plugs wires and
Delco sparks that are 2 heat ranges hotter than stock.
I tried
this modification and my fuel pressure went from 30# to 40# with only this
fifteen second mod. The modification is that I removed the vacuum line
from the factory fuel pressure regulator. Also, I capped the fuel
pressure regulator connection, so no dirt would get in, and plugged the
vacuum line, to maintain vacuum on the engine. I tested the car and
noticed a serious change in acceleration. I then took it on the highway,
set the cruise for 70 with this mod I was getting an instantaneous reading
of fuel mileage of 28-29 miles per gallon. I pulled off of the highway
and switched back to having the vacuum line connected. I immediately
noticed the power had reduced. I again took the car over the same stretch
of highway and the mileage went down to 26-27. I thought the second
mileage test would be higher than the first. I checked with my mechanic
on this and he said the car is just running more efficiently with the mod
than without. One other thing that got better for these test runs with the
mod was the temperature of the engine went down. Normally, when the car
is warmed up and going down the highway, it\’ll usually run about
208-211 degrees. With the mod it went to 184-187. My mechanic said that
that may be caused due to the cooling effect of more fuel entering the
cylinder. I don\’t know if the temperature differential is going to be
a constant, because as you can tell, the tests I did were not scientific
in any way. But, I feel there is an improvement, if only in my car.
I was told about this mod. via someone who works on, restores
and sells parts for nothing but Corvettes. So I thought I\’d give it a
Just make sure that the pressure you attain, if you do this
mod, is not too high for your system. Of course you can always put a
small needle valve in the vacuum line to reduce the press., if
If this works as well on all, none or slightly
modified, Corvettes as if did on mine, then there are going to be a lot
more wolves in wolf\’s clothing out there:-{}.
Blue Max

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