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i recently bought a zex dry nitrous kit and the previous owner who had a ze'd mx-3 who owned the kit before me told me that the tps voltage is too low for the kit to work so i he had to use a trigger button , im still confused on this , i know theres a switch to arm the system and all but does he mean that the whole "wot release system" wont work , therefore defeating the purpose of a zex kit? im sooooo confused here
any help is totally appreciated

Mmmmm, I don't know about ZEX, but with my old NOS system the way it worked was...

you have 12 volt switch on the dash to arm it... you can't simply use a switch to arm it by itself or it will inject nitrous all the time as soon as you hit the button. Turn it on at a light, deceleration, between shifts, whatever... it will come on. I'll assume that you can understand why just using a switch would then be unsafe for most of us.

So how to make driving the car possible with nitrous? Add more switches in series so it will only activate when you want. Add a switch to the throttle plate to make it activate when you are only WOT. You could also add an rpm based switch that will only activate (or de-activate.. depending on your primary concern) at certain rpms (MSD makes a cheap one). Nitrous controllers and such would just be an intelligent switch in series with main power to the line.

Why the guy even thought about using the 5volt signal from TPS or whatever is beyond me. In order for it to be in series to the nitrous solenoid which requires 12 volts, the switches must handle 12volt.

you should be using something like the one NOS has... you bolt it onto the TPS creatively (through the bracket which you can bend and manipulate). The idea being that when throttle plate is in WOT position, it pushes the long lever on the microswitch they supply with the bracket and closes the circuit... thus giving you nitrous only when switch on dash is on, and only when that switch knows it is WOT.

Summit racing supplies them... although if you spend a little effort you could find a similar microswitch for $5 instead of their $60 or whatever and make brackets of your own.

http://store.summitracing.com/default.asp?target=eproduct.asp&N=120+4294925143+4294925132+301168

I'm not familiar with the zex dry kit, but i know the zex kit requires a certain amount of voltage to come from the TPS wire to engage the nitrous. Call Zex, find out what the volatge is, then take a volt meter and see what your tps reads at WOT (make sure your key is turned on). It's the second wire from the top on the TPS. If it is indeed too low, just ask zex what kind of push botton you need. I am sure they will tell you where to buy one.

aaaaaahh ha... I guess you learn a little every day. Sounds like a much better idea to have that built in activation to run off TPS output voltage (for ease of install). At least better idea most of the time.

The mazda TPS is a bit 'off' from most TPSs. It's set up to send an on or off signal. There isn't the nice linear rise you would normally see. I don't think it outputs anything near 5 volts which would be your average TPS output, but that's from a measurement taken over a period of a few seconds several months ago. Probably best to measure and phone them up as mx3man says.

i have messed with mine recently, mine is set at .503V at close and only reads about 3.65 or so at WOT, and i dont see why you say its not linear, mine went up pretty linear when i opened mine slowly

Originally posted by papa roached:
i have messed with mine recently, mine is set at .503V at close and only reads about 3.65 or so at WOT, and i dont see why you say its not linear, mine went up pretty linear when i opened mine slowly

yeah it's the same here..
but you know morgan.your voltage at idle is pretty low...you are almost not within the range..people with probe that had that voltage and turn it too .75 said to have noticed an increase in throttle response..you may want to try that out

BPT is definetely not linear.

Originally posted by babyblueMX3:

Originally posted by papa roached:
i have messed with mine recently, mine is set at .503V at close and only reads about 3.65 or so at WOT, and i dont see why you say its not linear, mine went up pretty linear when i opened mine slowly

yeah it's the same here..
but you know morgan.your voltage at idle is pretty low...you are almost not within the range..people with probe that had that voltage and turn it too .75 said to have noticed an increase in throttle response..you may want to try that out

i read that post and i tried .75 and everything between that on .503, it was at .53 stock and it runs alot better with .503 than it did with the stock and all my VIRS still work so im happy