dubulup

TIA

BLUE TII

iTrader: (9)

Check with fuel injector manufacturer for lowest recommended pressure for good spray pattern??

In my very limited experience I have found the higher flowing injectors need higher fuel pressure- especially when used below the recommended duty cycle.

dubulup

^good thought.

I should have given more info about my set-up...

13B-REW, single turbo, 550/1680 injectors.

dubulup

bosch was absolutely ZERO help...said its application specific.

BLUE TII

iTrader: (9)

Looks like you will have to experiment. Are you looking to run a very low base pressure to limit fuel pressure once at high boost to a reasonable level in order to get more flow out of the pump?

I bet you can run the 550 primaries at a low pressure w/ pretty good results if they are clean and then stage your 1600s at a higher boost where the fuel pressure has been raised to where they will have a good spray pattern.

You might max out your primaries before you can get your secondaries online smoothly though since there is such a size difference.

dubulup

I dropped fuel pressure to around 35-36psi BASE.

I found my maps were entirely too rich at 38psi; 10.9:1 A:F, and wanted a quick change to drop it. Even after dropping the pressure, I had to lean out a lot of fuel to get into the mid 11's.

1680s come on line just before 40psi and my pressure tops out at 52psi. I am having no issues suppling fuel at these pressures. It seemed running high pressure was to get more out of your fuel injectors...where it is not so crucial with my set-up. Maybe I'm saving pump life or maybe I'm bringing the pump into a zone where it can keep up-no problem. Only time will tell.