Would this be a good fuel pressure safety swtich?
http://store.summitracing.com/partdetail.asp?autofilter=1&part=NEX%2D15718&N=700+4294845251+4294903084+115&autoview=skuJust wondering how they work? The sense Fuel pressure dip below a certain point and they cut the power to the nitrous solenoid or what?
Also, where does it get installed on the fuel line? (Im running a Schrader valve tap for my fuel-in line)
That is a good switch. Below 25psi it will cut power to the Nitrous solenoid to protect your system from going lean.
60psi is max pressure but thats cool because contours run max 55psi regulated at WOT. You will run it inline in the middle of the fuel line coming from the fitting that is currently holding the schraeder valve, continuing from there to the fuel solenoid.
The wires run from 12v->fuel solenoid->microthrottleswitch->nitrous solenoid->ground.
Basically it will break the continuity of the circuit when fuel is below 25psi.
Run the biggest line you can fit on that fitting. You won't have a schraeder valve fitting there anymore once you replace it with th NPT-A/N fitting. Run a line out from under the manifold where you have room to fit it into a brass fitting where you can mount your pressure sensor and fuel solenoid. Don't worry, there is plenty of room to turn the line or buy one of the AN lines that have a 90 degree elbow with the fitting just like what we use on the turbo oil feed line.
Just be sure to wire the pressure sensor in series with the NITROUS solenoid for it to work right.
What size NPT fitting do I need to take the place on the schraeder valve?
You need a 1/16" threaded fitting, outputting to whatever size hose you're using (likely a -4AN).