ive replace my 255lph with a 340lph and my fuel pressure drop 6psi on my gauge on the rail. is it suppose to do this?? i thought the pressure should go up knowing its a higher pressure pump. anyone have a ideal if this is correct.

 

Pumps do not create pressure, they create flow. Hence the Liters per Hour rating, not PSI......

Your fuel regulator is what allows pressure to build, giving the pump something to fight against.

 

What is the max base pressure I can run to be on the safe side ? I had it On 80psi with the 255 and it drop to 76Psi after installing the 340 pump.

 

what kind of fuel regulator are you using?

 

Why are you running the pressure so high?

 

I have the aem. I was trying to squeeze as much out of the 255 as possible cause I was running out of injector(1000cc)