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Discussion Starter · #1 ·
how important is this to have in a nitrous setup?? wont the viper computer shut the system down if it drops anyways?
 

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plumcrazy said:
how important is this to have in a nitrous setup?? wont the viper computer shut the system down if it drops anyways?

Plum, I can try to get an exact number of when the stock system will shut it down, but I do believe it does....
 

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Discussion Starter · #3 ·
im also thinking my VEC2 will do it for me as well. i gotta aask sean when im down in florida on his dyno about THAT in april.
 

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The fuel safety switch keeps your N20 from spraying, in the event there is not enough FUEL pressure...Lets say your fuel pressure dips (would have to "dip" ALOT), shuts down, doesn't spray with the N20....But the N20 still sprays...What do we have:

An incredibly lean mixture...ie....GRENADE!

Don't skimp on the safety gear...Get the Fuel Safety Switch...It's cheap insurance.
 

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Phil,normal pressure for a stock car is around 50 to 55. Your car becomes severely symptomatic at 30 or so...now here's the gipper.

I'M SPEAKING FOR MY SET UPT WHICH IS NX. The max setting on the feul pressure safetly switch is 12.... 12!!!!! which is WELL below the point in which the car becomes symptomatic. it's just too low and doesn't make sense to mount it.


Your pressure is regulated by a conjunction of you O2 sensors and your injectors which keep your car at about 50 or so. Hope this makes sense.
 

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Discussion Starter · #6 ·
im NOt trying to skimp by any means. its my baby. bu im not really sure it is necessary in this case. I also think my VEC2 will do the same thing. i gotta do some homework on this.

thanx squirrel, mine is NX as well.
 

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Snake Bitten said:
The fuel safety switch keeps your N20 from spraying, in the event there is not enough FUEL pressure...Lets say your fuel pressure dips (would have to "dip" ALOT), shuts down, doesn't spray with the N20....But the N20 still sprays...What do we have:

An incredibly lean mixture...ie....GRENADE!

Don't skimp on the safety gear...Get the Fuel Safety Switch...It's cheap insurance.
Gerald,

I think Phil gets that. The moral of the story here is I agree, don't skimp, but here's the catch Gerald. If your feul were to drop..and drop it would have to significantly. AND you have a window switch (which I think Phil does), then your car would not have enough feul pressure to even operate at that RPM (in this case, most are windowing between 3 and 6K rpms). If your window switch is coupled with a WOT (which i think phil's is) then at WOT, your car wo9uld demand a greater feuol pressure that it could not provide, thus never firing nitrous. so your car would not "theoretically" have enough pressure to operate at any gear mind you, at 3K.

So, Phil, yes, gerald's right..if you have one, shit why not just throw it on, but it will NEVER be activated.

Hope this makes sense.
 

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Discussion Starter · #8 ·
i got one but im not happy with the placement of it. i can use it if i got to.

my window is by the VEC2 as is my WOT switch. sean roe just sent me some wiring diagrams for it to be done. im gonna talk to him on the FPSS too.
 

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A drop in fuel pressure will directly lean out the mixture, whereas the nitrous will remain fairly stable over the run. That is one reason for running a nitrous car fat or 10-11 to 1.

The fuel pressure switch is adjustable. I have mine adjusted it so that if shuts off the nitrous at 40 PSI (fuel). I log my fuel pressure and have come up with the 40 psi as a result of my log files. It is fairly simple to adjust. Set the regulator of your air compressor to 40 psi and and adapt the air hose to the pipe size of the fuel pressure switch, then, use a ohm meter to adjust the switch.

The oem PCM doesn't care about fuel pressure, it is monitoring closed loop (partial throttle) a/f.
 

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Discussion Starter · #10 ·
thanx jack, does the FPSS HAVE to be mounted directly to the fuel solenoid?....or can it be mounted anywhere in the line?

any ideas on where if it doesnt have to be directly on it.
 

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Jack B said:
A drop in fuel pressure will directly lean out the mixture, whereas the nitrous will remain fairly stable over the run. That is one reason for running a nitrous car fat or 10-11 to 1.

The fuel pressure switch is adjustable. I have mine adjusted it so that if shuts off the nitrous at 40 PSI (fuel). I log my fuel pressure and have come up with the 40 psi as a result of my log files. It is fairly simple to adjust. Set the regulator of your air compressor to 40 psi and and adapt the air hose to the pipe size of the fuel pressure switch, then, use a ohm meter to adjust the switch.

The oem PCM doesn't care about fuel pressure, it is monitoring closed loop (partial throttle) a/f.


Jack don't talk much, but when he do...he talk truth.
 

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You can mount the fuel pressure switch anywhere as long it is not near the fuel pump. There is more short time pressure deviation near the fuel pump that would cause the pressure switch to cycle.
 
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