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Here are the directions that came with my NX wet kit. These are easy enough, however I have a window switch and timing retard and need to know how to tie them into this.
My ignition (Mallory 685) has one wire for the timing retard. It is selected when the wire has 12V applied.
It also has one wire for the window switch. It is connected to ground when the switch is active.
Details are appreciated because I'm not very good with electrical stuff, especially when relays are involved. Also where would the timing retard wire go to on an LT1? The same place my tach connects?
First off, disregard how NX has the hobbs switch (fuel pressure safety switch) wired in there. The better way to put that inline is to put it on the ground wire side of the nitrous solenoid. That way the fuel solenoid is open allowing the fuel pressure to get back up while the nitrous solenoid is waiting for the Robbs switch to open the flow when the fuel pressure is stabilized.
Replace where they have the hobbs switch in the diagram and replace that with the RPM window switch circuit. Many of the window switches need to be installed on the ground side because they can not handle the amps on the hot side of the circuit.
To activate your timing retard, tie the single activation wire on the ignition box in with a new third wire coming off the green connection in the diagram.
I've re-read your explanation on why but I guess Im just too dense to understand the difference between having the FPS at the nitrous solenoid (-) wire instead of the relay (-) wire.
I guess where Im confused is why would you want fuel to keep spraying if your FP is too low to allow the N20 to spray? I would think that if FP is too low for the N20, then you wouldnt want any part of the system activating. Im still trying to learn.
I guess where Im confused is why would you want fuel to keep spraying if your FP is too low to allow the N20 to spray? I would think that if FP is too low for the N20, then you wouldnt want any part of the system activating. Im still trying to learn.
If I read his reasoning right...
When the fuel solenoid opens there is an initial drop in FP. The FP switch can see this at times and kill the system (closing both solenoids). If you wire it to just the nitrous solenoid it lets the fuel solenoid stay open and let the lines rebuild pressure before the nitrous solenoid opens up. No real damage done if just the fuel solenoid opens.
So the suggested wiring of the FPS should eliminate the FPS enduced fuel solenoid flickering that people always complain about with using a FPS. By preventing the fuel solenoid from closing, you wont repeatedly have a sudden FP drop everytime it opens. In theory, even though the FPS may see a FP drop and shut off the N20 solenoid, once the FP levels out, the N20 will automatically engage again.
I've read that if the fuel solenoid is dumping fuel without N20, it causes the engine to bog or run poorly from being flooded or something. Not true?
Yes te fuel solenoid will dump fuel if your nitrous solenoid never opens. As long as your fuel system is up to snuff, then it should be a very brief period that it goes fat. Mounting the FPSS at the solenoid ground does stop the activation flicker and allows you to set the fpss to a higher and safer psi setting.
Makes sense. Looks like I have some re-wiring to do this weekend. Thanks for the explanation guys.
Sorry, didnt mean to hi-jack the post with my questions.
Have you been having problems with the FPSS causing flickering or surging?