welllll on the 510 i need to get an electric fuel pump because the stock pump clearly will not pump enough. I dont know if anyone knows anything about SR20s, but do i need a fuel pressure regulator?

 

I don't know Nissan motors, but I would imagine that all cars use FPRs of some sort, otherwise, the fuel line would never build or keep a steady pressure because all the fuel would just pass right through the fuel rail and back into the tank.
Fuel Pressure Regulator. See? There has to be something to help pressure rise and fall.

 

Just get an FPR lol. Save yourself the worry. Its not even costly.