electrical gurus (Lou?) got a challenge

This isnt for my kz, but it is for my other kawasakiB)
Im trying to increase the resistane of a wire (attached to a temp sensor) by flipping a switch, and change back when the switch is off. the challenge is that the connection cant be broken, not even for a fraction of a second. if it is, the ecu goes into error mode, and shuts down the motor, which is exactly the opposite of what i want to happen:laugh:
the reason i want to increase the resistance of the sensor is so it will register colder and the bike will run richer when the switch is on. the switch will also be spraying nitrous;) :evil: :whistle:
basically the reason for this is to maintain peak power by running a correct map off spray and only richen the map up for use with nitrous when im actually using it. the alternative is to run a rich map in the power commander, or have a resistor plugged in all the time and it would only work good on spray....

Pretty sure this would work, quick and dirty I made you a diagram for a standard automotive relay. No idea what kind of resistor value you need though.

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Post edited by: loudhvx, at: 2007/05/16 06:38

Wouldnt you need a really really big resistor to make that work? I'm not an expert b ut I thought resistance in paralel (as you show with your diagram with the switch) divides, which is why I tried to find a way to put it in series instead. Considering the circuit must have close to 0 resistance wouldnt that be difficult to overcome? I'm not really sure but thats why I came up with the relay thing. I would be curious to know anyway.

Link to someone that can explain it better than me

Lou's circuit is correct.

Switch open, circuit sees 'R'. Switch closed, circuit sees 'wire'(very small R). Circuit is never interrupted.

In your parallel resistance formula, don't forget, 1/(almost zero) = very large number and 1/(very large number) = almost zero.

Post edited by: Duck, at: 2007/05/16 09:18

HAHAHA now I see! I am really dumb late at night sometimes! That is way more simple than I was trying to make it!

ok now the problem is my switch for nitrous completes a circuit, not breaks one :blink: it puts power to a solenoid. (using a very stealthy toggle switch to make the starter button the nitrous button)

Electrically speaking, your problem is easy to setup, but I'm more worried about you going into a lean condition. Are you experimenting? or is this modification a proven-to-work mod done by more than one guy? Do you have any documentation on this mod?

How quickly will the ECU respond to the resistance change in the sensor? When that solenoid kicks, that mixture will go lean instantly.

Doesn't your N2O setup have an interlock relay to prevent the solenoid from kicking before a fuel enrichner kicks?

... just trying to get a feel for what setup you have

Post edited by: loudhvx, at: 2007/05/16 15:07

ok here goes, it is going to be kinda expiremental. i was talking to a guy who did this, but i want to refine his setup. im going to be using a dry nitrous system. i want to add the extra fuel via the stock injectors like every other dry kit.
dry kits are a bolt on for a very safe 40 hp gain for fuel injected bikes with an air temp sensor in the airbox. you fog the airbox and the temp sensor (this is a different sensor, the one i want to put a resistor in is the coolant sensor, which is a proven mod to richen up the map) adds extra fuel due to much colder air. much more than a 40 shot and you need to run a rich map so it doesnt lean out.
the guy i was talking to was using a single stage 90 shot and he used a resistor to add the extra gas with the stock injectors. he used a petiometer(?) (vairable resostor) and cranked it up to the max and then backed it down till he got a safe, but not too rich air fuel ratio. this was a very violent change in hp and yes you guessed it led to a lot of wheelspin:evil: it was just a street setup so he liked it that way.
what i want to do is have a dual stage setup so it doesnt spin. wheelspin is the last thing you want in a dragrace!!! I want to have a "regular" 40 shot single stage that the ecu is capable of running, and then a second stage (about 35 hp shot) turned on and the resistor mod turned on at the same time to make sure it doesnt go lean.(i dont plan on running the second stage every every pass, just when i need it, so thats another reason for not going with a huge single stage) ill be taking out 2-3 degrees of timing at 80-100% throttle with my power commander so it will be safe that way too. that will only take a couple hp off when not spraying vs normal timing.
Ill be getting a wideband O2 sensor to tune the nitrous and adjust the resistor to get a good AF ratio
im not sure what you mean by an interlock relay. maybe thats only with wet nitrous kits?

Alright. I'll draw up a circuit. When you press the button you'll get the shot, but you'll have to hold the button to keep it going. When you let off the button, it stops squirting. Is that what you want?

Also, since the N20 is going into the airbox, when you let off the button, the fuel stops right away, but there is still fog in the airbox. Won't that cause a momentary lean condition when you let off the button?

Won't that cause a backfire?

Do you want a time delay on the resistor circuit so it doesn't go to "hot mode" instantly? That way the resistor will stay in for a split second longer than the N2O solenoid.

You read my mind. thats exactly what i want, only spraying when the button is held down. (the first stage will be on a wide open throttle switch, or "micro switch" and the second stage will have both so i can manually spray, but only if its wide open)
yes a timer so it stays rich for a split second would be a great idea! because even though it uses the air in the airbox very fast, it will have extra N2O for just a tiny bit of time. probly not enough to hurt it, but it might kinda stumble, im not to sure. I believe the guy with the 90 shot had a timer aswell, i think some sort of capacitor that took a sec to charge/discharge. let me try and find what he had....

Yes the damn ECU is to smart for its own good, any switch in the wiring no matter how fast it will turn the FI light on and kill the bike @ WOT.

So you can switch it on the fly, it uses a small timer to connect the resistor first and then the timer kills the normal circuit after the first circuit has already been connected, this way the wire is never actually broken, it has around a 0.1 second delay, then another little box that has a tiny relay and capacitors so it does the opposite when off the button, the capacitors takes about .3 of a second to drain which then stops the relay taking it back to stock temp sensor.

I am actually using an adjustable resistor which can be turned up or down to fine tune the ECU enrichening depending on how much nitrous you are adding.

Im adding 90hp dry with no power commander or timing retard, I know I should take a few degrees out for optimal power but I ain't blowing no more money on this n/a engine, im spending it all on a turbo setup.

251 STD totally stock internals, 163 on the engine.

The system is very cheap but it takes some time and small soldering to make it work good.

2 teeth down on the front and 251 at the wheel makes for a fun ride to say the least.

he was using a splash of 110 race gas in the mix though, taking out timing and running a bit less spray should make this unnecessary