Methods to wire N20 with an MSD & T-brake??

[Nashty]

My two step and transbrake are activated when I ground the activation switch. I want the Nitrous to engage when I open that circuit which cuts off the two steps low rpm cutoff and disengages the trans brake.

I'm thinking I could use a normally closed relay and wire it into that circuit. Then the nitrous would be always hot (while armed and the throttle switch was WOT). Then the circuit goes open, the relay closes and starts the nitrous flow. Only problem is then I have to arm the nitrous after the burnout, which is pretty minor though.

Any better thoughts?

 

[Razor]

Well the center leg on a 5 pin Bosch style relay is normally closed, use this terminal with your nitrous system and have a secondary whereby wont come on unless the throttle is at WOT. That way when you turn your ignition on, it cant fire.

Only issue I see if you do your burnout at WOT, or as you say wire an arm switch when you finish doing your burnout. Wonder if boost activating the nitrous may be another alternative for you, or use nitrous in a window switch fashion whereby it cuts on at low boost..then cuts off at a presdetermined level like 18 PSI for example.

I know your trying to make this automatic so you dont have to fiddle with more than needed.

Are you wanting to run the nitrous the entire pass?

 

[denn454]

thats the way i would do it. i have a no2 kit on the way, just wanting something to help out off the line and at the top end if i need it. bracket racing stuff.

the way i'm going to do it is run a master switch, once armed the throttle would have to be 100%, brake off, and be under 12# of boost with a manual over ride button. once any of those things changes, it would shut off. sounds very similar to your idea, minus the shutting off at boost.

you COULD make life hard on yourself and make it turn on when are you using a line lock to do a burnout? if so then you could turn the no2 off when the line lock is on through a relay. or if your doing a foot brake burnout wire it into the brake light, so when the brake is on it can't be turned on.

 

[galoush]

Im using a WOT micro switch and an MSD window switch with pills . 3000rpm pill turns it on and a 6000rpm in case it over revs somehow . I dont think you want to turn it on below 3k rpm unless you want to blow the intake off the car , but i could be wrong . you could change pills to hve it shut off a little before a full pass , i think spraying it the whole track is the only way to go . a 100 shot is no monster hit by anymeans so giving it a quick shot i dont think is going to gain you much , if anything its going to make tuning harder. with the 100 shot on my car ive seen 5-7mph more in the 1/4 , i hit it with the 150 on the street but havent tryed it on the track yet .

 

[Nashty]

I've got my relay wiring complete. I'm going to hose it the whole pass.

The center pin is a ground when my T-brake circuit is not active. When that relay (t-brake relay) turns on, the ground on that center pin goes open circuit.

I'm going to power the nitrous relay +12V switching through the arming switch. The ground from the Tbrake relay will go through my throttle microswitch.

Tbrake on = no ground for N20 relay
Tbrake off = ground complete for N20 relay.

I'm also going to put a purge solenoid and relay in there.

I bench tested it last night, worked fine.