Where do you put your FPSS?
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I was going to install my FPSS right off the fuel rail like is typically done, but I ran across an install pic here somewhere the other day that had it after the fuel solenoid and that made a bit more sense to me. Just looking for more info on where everyone has their FPSS installed?
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Yeah, I wasn't going to install one but it was in the kit so why not. I just figured the typical was off the rail as suggested, but I saw the one install with it after the noid which kind of makes sense. If the fuel noid gets plugged or doesn't open, it won't allow the nitrous noid to work. I would think though that a -3an running to a fuel jet would still be enough of a restriction to allow the switch to see pressure. I mean, if it's not going to see any pressure, then your fuel rail won't have pressure either.
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gillbot,
The fuel pressure safety switch is designed to keep the system from activating in the event of fuel pump failure. So it needs to be in the fuel feed before the fuel solenoid.
The only thing there is to save the motor from if the system went lean is a lean cut off switch. Dyno Tune offers a nice one. However if you are not going to wore it to a wide band dont waste your time and money.
The best preventive is to make you are using a good quality solenoid designed for todays fuels and good wiring connections.
Dave
The fuel pressure safety switch is designed to keep the system from activating in the event of fuel pump failure. So it needs to be in the fuel feed before the fuel solenoid.
The only thing there is to save the motor from if the system went lean is a lean cut off switch. Dyno Tune offers a nice one. However if you are not going to wore it to a wide band dont waste your time and money.
The best preventive is to make you are using a good quality solenoid designed for todays fuels and good wiring connections.
Dave
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My fpss is right before it goes into the reg. Then off to the noid.
I got a good question..
If you feel the fpss is faulty, can you just hook the two wires together and the fpss is now unhooked and the kit work ok?
I got a good question..
If you feel the fpss is faulty, can you just hook the two wires together and the fpss is now unhooked and the kit work ok?
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So most people don't use a FPSS?
I am using all HSW stuff, (sorry nitro daves)microedge plus, interface, wideband O2, etc.
Is using a FPSS going to cause problems? If so how?
Is using one overkill, if there is such a thing?
Thanks for any input. I am wiring up my nitrous kit at the moment.
Jason
I am using all HSW stuff, (sorry nitro daves)microedge plus, interface, wideband O2, etc.
Is using a FPSS going to cause problems? If so how?
Is using one overkill, if there is such a thing?
Thanks for any input. I am wiring up my nitrous kit at the moment.
Jason
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I think the biggest problem i've seen with FPSS's is that people don't take the time to set them properly.
Dave,
That was my thought but seeing that picture got me thinking. That's where I had it installed and where i'll likely leave it but I had to ask. Never really thought of putting it there to be honest, it just sparked my curiosity.
gillbot,
The fuel pressure safety switch is designed to keep the system from activating in the event of fuel pump failure. So it needs to be in the fuel feed before the fuel solenoid.
The only thing there is to save the motor from if the system went lean is a lean cut off switch. Dyno Tune offers a nice one. However if you are not going to wore it to a wide band dont waste your time and money.
The best preventive is to make you are using a good quality solenoid designed for todays fuels and good wiring connections.
Dave
The fuel pressure safety switch is designed to keep the system from activating in the event of fuel pump failure. So it needs to be in the fuel feed before the fuel solenoid.
The only thing there is to save the motor from if the system went lean is a lean cut off switch. Dyno Tune offers a nice one. However if you are not going to wore it to a wide band dont waste your time and money.
The best preventive is to make you are using a good quality solenoid designed for todays fuels and good wiring connections.
Dave
That was my thought but seeing that picture got me thinking. That's where I had it installed and where i'll likely leave it but I had to ask. Never really thought of putting it there to be honest, it just sparked my curiosity.
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I would say you should monitor your fuel pressure during a run, then use an air compressor to adjust it but i'll let the "pro's" chime in.
Mine came pre-set at 50psi, at idle my pressure is at like 62psi but ive never checked it during a WOT blast so I don't know how far it drops off.
Mine came pre-set at 50psi, at idle my pressure is at like 62psi but ive never checked it during a WOT blast so I don't know how far it drops off.
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I know what's coming next, if you trust your wideband. Well I would trust it more than I would the FPSS and since it's good enough to count on form my N/A runs.
Just sayin'... I don't have near the experience a lot of you do with Nitrous so I'd be interested to hear what you feel.
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Mighta been one of my pics. The noid is a NX Lightning, it has a flow through port, so it can be on "other side" of the fuel noid. For my application it was the cleanest install option, and worked fine. I eventually ditched the FPSS for an AFR shutdown built in to the Trick Performance V Guage.
Below is an 1/8 mile pass (NA) with fuel pressure being logged from the far side of the noid. Racetronics pump, new fuel filter got as low as 47 PSI upper RPM of first gear. The pump recovers on the shift, but you can see if your FPSS is set for around 45 PSI, one could dip into the window for the FPSS to shut down the nitrous during a pass.
FP PSI far right second batch of 4 from the top PIDs logged in magenta
![](http://www.retrorelics.net/jim/Boards/Corvette/Dec07Fuelnoid.jpg)
Below is an 1/8 mile pass (NA) with fuel pressure being logged from the far side of the noid. Racetronics pump, new fuel filter got as low as 47 PSI upper RPM of first gear. The pump recovers on the shift, but you can see if your FPSS is set for around 45 PSI, one could dip into the window for the FPSS to shut down the nitrous during a pass.
FP PSI far right second batch of 4 from the top PIDs logged in magenta
![](http://www.retrorelics.net/jim/Boards/EFILive/Fuelpressurescreen.jpg)
Last edited by Beer99C5; 09-18-2010 at 02:14 PM.
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Nope, that wasn't the pic I saw but great info there!!
I was thinking of setting mine for ~40 psi anyway. Many FPSS's come pre-set at 50 psi and I figured that would be a bit high. That could be why most people ditch them, they leave them set at 50 and they'll drop off the N2O during a pass when pressure drops.
I was thinking of setting mine for ~40 psi anyway. Many FPSS's come pre-set at 50 psi and I figured that would be a bit high. That could be why most people ditch them, they leave them set at 50 and they'll drop off the N2O during a pass when pressure drops.