WHat should I set mine at?

 

My fuel pressure runs about 55 psi. I set mine at 45 psi.

 

good question, i would like to hear from the sponsers on this one..... what psi they recommend and how can you set it accurretly?

 

i wouldn't set it any more than 5 PSI lower than what it normally operates at. most higher hp cars with semi built up fuel systems see a fuel pressure drop of 2-3 PSI when they go WOT. i wouldn't want to be spraying if it drops off more than that...especially if you are spraying below 3000 rpms.

 

I agree with this. However, they are normally set lower from the manufacturer to cover the weaker fuel systems that have a supply issue. Remember when dropping pressure you'll be going leaner, and that can be dangerous. to set your sw, just turn your screw clockwise to raise pressure or set point, and counter clockwise to lower set point or pressure. You can do all this with an air compressor.
Robert

 

So are you saying I should set it 5 psi below what it comes set at from the manuf?

What do they come set at?

What is stock FP in our cars?

I don't plan on spraying below 3K RPMs

 

I was referring to not setting the switch more than 5 PSI lower than what the car's fuel system normally operates at. The NX FPSS comes preset at 35 PSI. Stock fuel pressure is about 58 PSI in our cars...it varies from car to car, but I believe GM's accepted operating range is 55-60.

 

So I should set it to 55?

 

Not until you know what your normal fuel pressure is. If your fuel pressure runs about 55 psi or just a little above you will be tripping the FPSS and shutting the system down or resulting in surging (the system going on & off as the fuel pressure changes.

 

Robert...

how do you do this with an air compressor?

 

I used some 1/8" pipe fittings and some adapters to hook the air hose from my compressor up to the FPSS. I set the air pressure regulator to 0 psi. Then I hooked a continuity tester to the FPSS terminals. (A 12 volt or any low voltage test light will work. The FPSS is a normally open switch so no current should flow through it at 0 psi. I slowly turned the air pressure regulator to raise the pressure when the continuity tester beeps (or the test light comes on) that is the pressure the FPSS is set at. If you want to change it go back to 0 on the air pressure, adjust the scew on the FPSS and repeat the process until you have it set at the desired psi.

 

much appreciated!

 

Well what is normal FP for these cars?

 

58psi if memory serves me right... seems to be the "standard" accepted psi

 

The factory manual for an 02 Corvette says 55-62psi.

 

Well the NOS FPSS I have is preset at 50psi. Should I just leave it alone?

 

I would leave it alone and see how it works. Do you have a fuel pressure gauge in the car that you can watch?

 

I'm putting an Auto Meter FP gauge in w/the nitrous kit