Fuel pressure question!
 

It's like this, my standard FPR started to malfunction so I removed it from the fuelrail, then I hooked up an aftermarket linear FPR instead.

My question is, what fuel pressure should I use if I want to be in the "safe zone" but still want the engine to produce power?
I don't have a wideband controller yet so I can't see my AFR value.
I'm planning to max the stock turbocharger (12psi of boost).

My mods are:
Stock turbocharger
Rtek 1.7
720cc secondary injectors
Walbro 255lph fuelpump
FMIC

Or should I get an progressive FPR instead?

It's in the FUEL section of the free FSM online.

Does the stock FPR work like a linear FPR cause I thougt it was an progressive but I'm an idiot =P