so close yet so far

[EODMonkey]

so i figured i'd put my car up on the dyno to see where things were at, thinking it was running pretty well.. boy was i wrong. i knew i had an issue with fuel pressure under boost, i'd see about a 5psi loss under full boost but good a/fr numbers. so we hook my car up and first pull she chokes at 5500rpm, so we check the data and i couldn't believe my a/f was 15:1 when all along my wideband was showing 10:1 under boost and no knock. so after adding an additional 40% in fuel up top to bring the numbers down we saw my fuel pressure dropping into to mid 40's and figured it was time to call it quits until i upgraded the fuel system some more. really not what i had expected to see but so far she put down 650tq and 610hp not really good but i guess since i ran out of fuel pressure i cant complain. just got my new wideband sensor in and now i'm planning out the fuel lines and fpr. if its not one thing its another.

[Blackbirdws6]

At least you caught the issue before something more serious happened. What fuel system are you currently running?

[EODMonkey]

yea i got lucky there. i'm running a walbro 255 with a kb boost a pump. i knew i'd have to get a fpr but things were looking pretty good without it. i'm ordering fast rails and an a1000-6 fpr so that should take care of the pressure issue. i just got the new wideband sensor and have to put that in.

[Blackbirdws6]

Yea you definitely need more fuel than that for the power levels you are achieving. Why not run dual pumps in the tank?

[S.J.SLEEPER]

you NEED 2 pumps!!!

[EODMonkey]

I was thinkin about that, kinda had my hopes on one pump but of course funds are becoming an issue. If I go dual though I think I would want two aero 340's. Aeromotive rates them pretty well. "Flow at 60psi is 465 lbs./hr @ 13.5 V (Using 6.2 lbs per gallon)
465 lbs/hr / .5 NA BSFC = 930 Crank Shaft HP
Remember this pump flow and not a system (i.e. lines and rails). In order to get the most out of this pump it would require fuel system upgrades (lines, rails, pump wiring and reg)"
I'm running 60lb Siemens injectors but I haven't looked at the duty cycle since making the changes.

[EODMonkey]

I was looking around earlier and I saw something interesting. I've always seen people rerun lines and put a fuel pressure regulator under the hood but I saw one mounted under the rear where the factory return intersects the feed by the tank. Anyone ever done this before? I saw it on aps performance's website.

[EODMonkey]

What a pita. Had to take the intake off to do the rails because of one bracket So I figured I'd get rid of the air injection just cluttering up the engine bay. Now to clean everything and put the nice new things in

[EODMonkey]

just finished with everything, but i have a question. my fpr is set to 58psi i can see it climb as my vacuum decreases but should i go below 58psi when my vacuum increases as well?