I was curious what kind of fuel pressure the old girl was making so last night I hooked up a temporary fuel pressure gauge to get some readings. At idle I have a solid 5psi and crusing at 70mph it varies from 3-4psi. The first time I floored it, the gauge slammed to 0 before I got to 75mph and continued to stay there until I let off the throttle. Actually, I wasnt too suprised, but I figured I'd have atleast 2psi, but the gauge drops to 0 before I can even get the turbos spooled.

Now for the stupid question of the day....
I know you see better throttle response with increased fuel pressure, but is there any HP advantages and if so, how much? I know there has to be some for obvious reasons, but any idea how much more HP you would see with an abundant fuel supply?
Thanks,
Cody

 

I cant give any HP info. however the fuel is what cools the pump. If you go to zero, your not keeping your pump cool which can mean premature injection pump failure. You might change your fuel filter and see if it goes up. From there I would change the transfer pump. Mine reads 6 PSI at idle and wont go below 4 at Wide open throttle, and I dynoed 332 HP.

 

Cody, sounds like you have a normal, healthy stock lift pump. This is what you get out of a stock LP. Replacing the LP with another stock diapragm lift pump won't do you any better.

As far as the HP gain, I doubt anyone has dyno'ed before and after a piston or aftermarket lift pump install. But if no gain, I agree with Frostie as at least you would know your VE is sufficiently getting fuel and cooled.

 

Do yourself a favor and get something to keep up with the pump and see if you get any more boost out of it. After going to the Fass pump I can hear the blow off valves go off again. Without it my old system was going south on me and I was loosing boost. So if I was loosing boost it would seam to me that I am loosing power also. I did notice a difference after the Fass install. You are really going to need a new supply pump before you put on the big injection pump.

Stomp

 

What do we have for options as far a increasing psi? I have read about the piston pump but don't know much about the FASS. Thought that was a 24v thing. Anything else out there to consider? Maybe a pusher pump to help out the stocker?