methanol injection

i have seen a few posts on the internet of people trying to do the same thing i am, how ever the ones i found are incomplete and a bit misguided i suppose.

so let me start with the complete idea first. i want to add 6 (one for each cylinder) secondary injectors to my v6 petrol gas engine. have it controlled by my arduino uno, using an input signal from my MAP sensor. it will read overall manifold pressure (vacuum or boost), the coolant temperature sensor, and the air intake temperature sensor. then control the spray of water/methanol mixture into the combustion chamber.

the arduino would turn on with the engine, check the fluid level, send a signal to my mega squirt telling it what fuel and timing maps to use, turn on the water pump, calculate the boost level, and temp of the coolant and incoming air, decide how much water/methonal would be necessary, and opening a solenoid sending the water/meth mix to the sprayers which would spray right into the cylinder...

my ideal set up,

a signal from the ignition or megasquirt telling arduino the car is running and its time to play, and kick on the water/meth pump

a level sensor in the water tank sending a signal out to my megasquirt to tell it to switch fuel and timing maps when i run out of water/meth, (wether there is water to be used or not) and to shut off the water pump if empty

sensors already onboard the engine (map, coolant and air temps) telling the arduino "engine conditions"

arduino processing this and sending a signal to the an inline solenoid to open sending to correct ratio of water/meth to the cylinders.

summary.... i have the hardware more or less figured as far as parts to use and the size of the commercial sprayers (not fuel injectors) figured for my horse power goals... but not really all of what is needed to add tot he arduino bored to control everything

my biggest problem here is being able to program the arduino to take in the information and spit out the correct water/meth needed for any given point in time.


a little side note/idea)... if i could use fuel injectors (maybe for E85 since they are corrosion resistant) and have the arduino pick up the pulse signal from the megasquirt... or maybe the cam sensor... and have my secondary injectors spray the water/meth mixture only when the corresponding valves are open... I don't know if that would be beneficial or not, but it sounds like it would be.


Forget it.


If megasquirt can send a signal, use that instead. You don't want a $10 microcontroller and a DIY setup dictating whether or not a piston melts...

I am not familiar with MS, but I had meth injection set up on DSMLink (for DSMs...) and all I did was set an RPM and Boost threshold for the ECU to signal a relay that turns the pump on 100%

I had a dual map tune that switched over when the relay was activated.

I tried using a progressive controller and it sucked. Keep it simple. A good tuner can work around an on/off switch, and from my interactions with others, it is the preferable method even from a tuning standpoint.

Conclusion: I agree, do not use an arduino to control meth. Also do you know what formula would input the parameters you gave and output an appropriate pulse width?

Lastly, you never mentioned the hardware that would control the solenoid. Arduino does not have the output power to directly control such a solenoid. I believe you would need to do a little more research there. A simly relay would not suffice since it does not have the speed required.