I have been reading everything being posted regarding fuel pressure/pumps/injector compatibility thanks to my SX pump crapping out at the track. Apparently turning the pressure up to 80 lbs was not making the pump happy. Before the pump failure, 80lbs would make it smoke a lot more than the previous 60lbs, and the truck was running 1/10 faster in the ¼ mile. It smoked out the lights for the first time using this pressure. This is contradictory to what I have been reading and have been told.
I now have the FASS system installed which might add another small wrinkle to the equation. It has a return line going to the tank directly from the FASS for the extracted air. I used a ball valve on this line to further regulate the amount of fuel returning to the tank. I can’t say for sure but this may help move more volume of fuel to the heads. I am currently running 62lbs at the regulator.
Now a few questions:
• Why would the truck smoke more with the pressure set too high? Doesn’t more smoke mean more fuel?
• If the fuel pressure was too high, why was the truck running faster?
• Could there be a weak component that would be helped by excess fuel pressure?
• Will higher pressure kill the FASS pump?
• Most importantly, what are your findings regarding MM’s and the best fuel pressure to use for performance and fuel mileage? I have been told that 55lbs nets a few more HP than higher pressures. Seems low to me and it nets less smoke than higher pressures.
, I do have the regulated return sump feed fuel system.