What does Static/Target Rail Fuel Differential Pressure mean?
 

MS3PNP Pro on a 99 1.8. I'm trying to learn every field just for posterity, rather than just copy a bunch of data.

Under Fuel Pump Settings, for Static/Target Rail Fuel Differential Pressure, it's set to 43.5, and says "The fuel rail pressure in PSI referenced to manifold pressure. Typically 43.5PSI for many installs." I'm having trouble understanding this, I thought NB Fuel Pressure was a constant 60psi, but can't figure out the final number. On some NA basemaps, I see 42.9 that confuses me too.

1. Can someone clarify how this number is derived?
2. What should I anticipate happening by raising or lowering this number? (more or less pressure, causing bandaids to VE?)

Thanks!

That does nothing on a miata. Your fuel pump runs full speed all the time and a mechanical regulator keeps the pressure constant. That feature is there for systems without a mechanical regulator where fuel pressure is controlled by changing the speed of the pump.

Thanks very much! I mistook it for some part of a calculation. Chasing my tail again... :)