Hey guys Im sorry to keep bugging everyone but I kinda need to know what Im shooting for it Idles at 62psi and then at high rpms it will drop to around 40 to 45psi. What is normal pressure drop for what I have and also I still have the stock lines and stock regulator thanks again for your help

 

I have almost the same identical setup as you, and I've never seen my fuel pressure go below 57-58 at WOT. That's with a Warlboro 255, hotwire kit, and 60lb injectors. I also idle right at 62psi.

BTW, my sig says 42lb injectors, but the above information is taken with the 60s I previously had.

 

Im running the same set up with a warlboro 255 and 60lb injectors on stock lines and rails. I idle right around 62-65 and never drop below 56-58psi

 

youre not supposed to drop fuel pressure...its supposed to increase at WOT actually

 

Stock regulators aren't vacuum/boost referenced so at WOT it "should" stay the same or drop slightly....

 

If you have a correctly sized pump, there should be 0 pressure drop at WOT.

 

I should have the correct pump it it a 255lph racetronics with a hotwire kit

 

Well with everything I did to it today it may be unsalvagable I think I need to start over with a new bucket

 

I actually have this same issue, i have a racetronix 255 intank and my fuel pressure at WOT used to drop significantly to about 30psi from 60 at idle so i added another 255, but inline though so now at idle im at 60-62 psi and at WOT it goes to about 40-45 psi...... any help is appreciated guys, i have stock rails, 60# motron injectors, SD tune, and im procharged about 9-10 #'s of boost.

 

Possibly a restriction somewhere? Maybe run all new fuel lines to and from the tank.

 

would the stock lines really be THAT much of a restriction???? i have checked everything for blockage or restriction and nothing, everythings good to go...

 

Walbro, hot wire kit, MSD boost a pump, stock lines and regulator.
Idles around 60 psi and drops to around 48-50 psi at WOT. ???

 

Are you guys using mechanical or digital gauges to verify your fuel pressure?

 

mechanical autometer but i also hooked up another gauge at the rail to make sure and it still drops to 40-45 at WOT

 

I HAD THE SAME ISSUES,DO THE TWIN WALBORO INSTALL,THEIR IS ASTICKY IN HERE.i TOOK THE TANK OUT 3 TIMES BEFORE.TWINS AND NEVER LOOKED BACK.ENGAGE THE SECOND WITH A HOBBS SWITCH,NO TOGGLES,CLEAN AND LOOKS GOOD.AND IT WORKS.

 

Autometer Mechanical

 

Just because something says Walbro on it doesn't mean it's good. I've seen many bad walbro's in my life. I've got one in my Syclone with a Boost referenced AFPR & the pressure will come up for a second, then fall off & by 10# of boost my motor is bucking. This is the 2nd walbro I've personally had go bad, I've known of more others.

 

Just out of curiosity... when was the last time you changed the fuel filter? Maybe that is restricting a bit or well over due?

 

Well I finally just got tired enough of chasing so I ordered a twin system from Lonnies and a new bucket so it will be here in 10 days also Im running -8 from the tank to Lonnies filter then to a set of billet rails so I figured if I change everything Im sure to fix it and Lonnie told me since most of the racetronics pumps are good to 550 hp he said that with my 9inch its probably robbing just enough hp to keep the single pump from doing it and I did think of the fuel filter but it wasnt it either but thanks to everyone for all your help without this site I would really be lost

 

Good choice! You won't have to worry about fuel issues again.

I just wanted to point out to other who are experiencing pressure drop with FI setups. Take the amount of pressure drop at the rails and add the amount of Boost pressure you're running to get your Actual pressure drop. So, at 40 psi WOT and 10 lbs. of boost, your actual pressure is 30! Be Careful!