Re: fuel pump ques?
sy#276 said:
how much hp or boost is a walboro 255 good to? and also if im runnig 18psi and went up to 24-26psi how much usually hp gain will there be on a 20g or how much hp gain for 1lb of boost?
It is sort of is double sided question.
The higher the fuel pressure the less fuel the pump can supply. Since we have a rising rate fuel pressure regulator, if the base fuel pressure is at 45psi it will be at 70 psi with 25psi of boost. A Walbro really start to drop off at 80 psi (even the high pressure model). The main reason (note: not only reason) to run higher base fuel pressure is to allow smaller injectors to supply more fuel. If you keep the fuel pressure reasonable, I have notice 600hp is do able with an intank fuel pump. Will a walbro produce enough fuel at 75 psi to feed 600 hp I really don't know, but I would guess at 80psi it would be a crap shoot. In theory suposedly at 40-50psi at walbro will supply 800hp, but I don't think the rest of the fuel system is upto that task.