Alright, Im in need of a fuel pressure safety switch. Been using a small shot of nitrous for too long without one and have a question.

Alright, I understand that my stock fuel pump runs around 45-50psi or so, im replacing it with a 255lph walbro later this month.

When shopping for a FPSS I found a nicely priced one from NOS. It says it is adjustable 25-50psi. The following is assuming I have it adjusted to 50 PSI for examples sake. Its installed properly, set to 50PSI.. Now.. that means it will only allow my nitrous to be sprayed when its at 50PSI or higher, correct?

Just trying to verify before I end up with one I cant use, even though im pretty sure I got this right. Never hurts to ask for a double check.

PN is: 15685NOS

-Lurius

 

i think it goes the other way you adjust it to not spray if it gets below a certain amount of pressure

 

With it set at 50psi, that means once the FPSS reads less than 50psi it will ground the nitrous system and stop spraying, but YES you are correct!!!!

 

Awesome, Thanks guys! Put away the bottle for winter and am itching to use it this spring, want everything to be perfect. Next im going to do away with the push button and go with a window switch.

-Lurius

 

the Fpss is closed when above the set pressure. When pressure drops it opens causing an incomplete circuit to ground or to a timing tuner/window switch

 

Correct but you have it backwards - the FPSS is put in the path to ground. The FPSS closes a contact and completes the circuit to the noids (usually thru the window switch) when sufficient pressure is present, and opens, thereby breaking the ground when it drops below a threshold.

 

Correcto mundo.
Robert

 

So do I turn the allen socket plug clockwire, or counter clockwise to set it to 50 psi?

-Lurius

 

Lurius, clockwise will raise pressure or set point. counter clockwise will lower the set point or pressure.
Robert

 

Awesome, thanks! =)

-Lurius

 

How do you accurately set the FPSS? What is the optimum psi? I was thinking 40psi.