Fuel pressure regulator

[Smithaam]

I have fitted a Black Top fuel rail to my ST170 engine and using the standerd fuel pressure regulator. The bottom of the regulator there is a small outlet tube and I'm guessing this is to go to the inlet manifold?? I'm building a custom plenum to use with standerd intake and throttle body.
Thanks

[Graham]

yes the small tube goes to the inlet plenum so the pressure reg adjusts the pressure to offset manifold vacuum or pressure, IF you are running n/a and using aftermarket management you dont need it

[Smithaam]

running an Emerald ECU so does that mean i can just leave it as a breather?

[Graham]

yeah just leave it disconnected

[Smithaam]

ok thank you