adjustable fpr settings?

[josherino]

I now have a full fuel system, and with my 660's I am not sure what to adjust my base fuel pressure to? I set the afpr to about 38psi with the vacuum line off and when I put the vacuum line back on it dropped to about 30 psi. please help, I want to adjust it correctly

 

[awdtalontsi1992]

It should be adjusted to 43psi with the vacuum line off. It should drop to 38psi with the vacuum line on. Good luck.

 

[steve]

The stock base fuel pressure (with the refference hose disconnected and plugged) on a 1G is 38 psi. The pressure will drop depending on your vacuum at idle whit the hose connected. (Remember to convert vacuum readings from inches or mercury to negative psi before adding to the base pressure for final values)

You can run a different base fuel pressure if you tune or otherwise correct for the additional fuel over what the ECU expects as long as your injectors and pump pump can deal with your max fuel pressure at full boost plus any pressure losses in the system.

The pump will have flow issues and a max pressure where the relief valve opens.
Fuel lines, fittings, and filters cause pressure drops in the system which means the pump pressures are higher for a pressure reading at the fuel rail.
Injectors don't always have good spray patterns at higher base fuel pressures.

Steve