I've had several people tell me that a fpss will cause surging and not to use one. What does the surge feel like? I think I'm going to still run the fpss, but I would like to know what to be on the look out for.

 

If you hook up a FPSS wrong, you can cause the surging your friends are mentioning. It will feel like you're flipping the nitrous on and off, and will be very obvious. Rather than not using one, I'd suggest not hooking it up wrong

Dave

 

i had surging problems. No matter how u hook it up unless u crank it down to like 25psi there will always be a SLIGHT surge because pressure will drop when the noid opens if u T it in b4 the fuel noid. Unless u hook up the FPSS up close to the pump and not the noid, but that would be a PITA. I pulled out my FPSS and replaced it with a FP guage. The surge isn't THAT bad, but IMO i don't like ANY surge, i want 100% clean hit.

 

i have no surging problems .. though i run a walbro 255 intank

i think anyone running nitrous should upgrade their fuel pump

 

What would be the wrong way??? you just take the activation wire and run it inline with it right


_______O________ <------like that

 

Yep, but lots of folks have it cut off the fuel solenoid as well as nitrous. You only want it to cut the nitrous solenoid.

Dave

 

the meaning behind it is to let the fuel pump catch up with the flow right. so It will actually shut the N20 off but still be flowing fuel . then when the pressure goes back above 35 psi it will turn on the N20 noid. I have a 255 lph and you can watch the fuel drop this happens really fast. you caint see where it drops to but the neddle moves .I do have it hooked up wrong. mine cuts off both

 

My switch came with no instructions.How do you adjust it?
Thanks,BC

 

LPEdave is right. That would run BETTER then having it turn off both noids. HOWEVER, even in this setup the nitrous will kick on for a second, turn off for a split second, then hit again and stay on. Some ppl may not notice it, but i do. It's because soon as the fuel noid opens, pressure drops, the nitrous noid is cut off, then the fuel pump catches up and then your set. But u still have that split second where fuel is going in and the nitrous noid gets cut. For safety, run it, for a 100% clean hit, don't

 

Dave's on the money. Also, make sure you mount the FPSS as close to the rail and as far from the solenoid as possible. This way, pressure drop at the solenoid won't affect the FPSS as much as you have more volume at the rail.

 

what if you adjust the cut off setting higher?