zero2005

Alright, there wasnt a specific forum for fuel system, but here's my question... if someone has a place this post should be, please feel free to move it

lets say that my fuel system is setup for a standard "high pressure" EFI running an adjustable (boost referenced) FPR at 45 psi to the rails (fed by two walbro GSL392's 255lph).

and i wanted to run a carb AND EFI setup (dont ask why! just keep readin lol) now, a carb needs low pressure (4.5 to 9 psi), lets say i run an adjustable FPR for a carb set to say 6-7 psi off the RETURN of the 45 psi FPR.

Will the pressure of the "low pressure regulator" effect the pressure of the "high pressure regulator" (ie problems with backpressure?)

i was thinking no, because the "backpressure" on the high FPR return wont exceed the 45 psi it normally outputs, and the excess pressure will simply "bleed off" (path of least resistance) the return of the low pressure FPR and return to the tank.

zero2005

Noone?
I'm not really very knowledgeable about how the Carb fuel systems work, but from what i've gathered, the FPR's for a carb are Non-Return style? is this due to the style of low-pressure pumps that are typically run on these kinds of cars?

if thats the case, can i run 45-65 PSI fuel pressure (on the high side of the injection system) to the INLET of an adjustable carb style 4.5 to 12 psi regulator (that has 1 inlet, and 2 outlets, think this is called a "deadhead" regulator as opposed to a "bypass" regulator?), will that damage the regulator?