I want to know if what I currently have is going to feed enough fuel for my engine (read sig for engine specs). I have a Holley 255 lph in-tank and the inline pump ATI gave me with my P1SC kit. I've moved up to 60# injectors. Will the in-tank pump be enough or should I keep both?

 

At 100% (no margin) and .55 bsfc and 15 psi would get you 450hp with the 255 alone.
Remember a 255 only flows about 50gph at 15 psi boost.

(50/.55 * 6.2)

edit:
The 6.2 is lbs/gal

And the 450 is actually at 80% capacity

 

I ran out of fuel pressure with my Walbro 255lph at 5000rpm and 4.5psi of boost so next year I will have 2 in my tank

A guy at camaroz28 had 600rwhp with a Walbro and a BAP...

/N.

 

Thanks guys. Where did the 6.2 come from though in your formula?

Also, does anyone happen to know what ATI's inline pumps flow? Sounds like I'll be okay if I keep the walbro in tank and the ATI inline (providing the inline flows enough).

 

I would use both pumps. I had the same situation on a customer who was running an fmu and wanted to go to 42 lbs injectors. We removed the fmu but left the booster pump. As long as the return can keep up (witch it can) it will work great. And with that pump you dont have to worry about loosing fuel pressure since that pump can supply up to 100 psi.