The safety advantages of Meth along with the increase in performance by allowing higher spark advance without knock are obvious but the amount of advance depends on how cool you can get the IAT sensor with the spray. Using something like this allows you to spray after the thermocouple in your card MAF sensor and makes charge pipe design and nozzle placement a lot simpler. Sends a 150Hz signal into the flex fuel sensor ECM input when meth pressure exceeds 150psi. You can delay the start and rate of spark advance with the tune and use the flex fuel spark table to establish max advance along with blending into a different AFR when spraying. You could even get creative and put a selector **** on your dash and have different performance levels by sending in 100Hz, 120Hz, and 150 for different EQ and spark levels.

Basically works like this:
There is a Normally closed switch on the head of the pump that opens around 150 psi. This coincides with the GREEN led on the AlkyController
When that switch is closed the output signal is clamped to ground.
Delay the spark advance with the Flex Fuel->Delay Volume setting
Slow the rate of spark advance with the Flex Fuel->Transition Volume setting
Control Max Spark advance with the Flex Fuel Spark table
Adjust the EQ with the open loop Alcohol table


DISCLAIMER:
This is an earlier system which I no longer use. I have yet to prove out how effective the Delay Volume and Transition volume settings work. Repeatability and resolution might be an issue, i.e: delaying advance by 0.01 liter (min setting), blending into max spark in 0.01 liter(min setting)... but then again if that doesn't work then advance would come in immediatley, just like current systems spraying on the IAT.

 

I know schpenxel came up with a way to do the same thing but used a pressure sensor on the meth line. Cant really remember how he wired it up to work though.

 

Pretty similar, I just had it ramp up the alcohol % based on pressure instead of doing it all at once. Up to 50psi was 0% ethanol then it would go up from 25% to 100% as pressure went from 75 psi to 150 psi.

It costs more to do it that way as you have to add a pressure sensor (alky control has pressure switch built in), more line, fittings, more wiring, etc. It was overkill IMO.

Honestly if I were doing it over again I'd make it more on/off like Phil's though probably... hard to beat for $10 and the simplicity of it

 

I give you a lot of credit for doing that. Laying out the board, writing the code for the processor, etc.. It was a small scale project but big projects go the same way, just on a bigger scale. Not to many people can do that stuff. I was just lazy and spent $10 LOL

 

Thanks

All it took was hours and hours of YouTube videos

You should have seen the test board.. well, you probably have an idea, I'm sure you've built much more complicated stuff. It looked like a jumbled mess but worked fine for almost a year before I had boards made

Hard to beat your way for $10 though...

Did you ever get the boost controller going?

 

Made 4 boards and getting them assembled this week. There were some fine pitch ICs and small 0603 SMT parts so I used the board house we use for my job rather than assemble it myself.



Honestly the understanding you got from doing that project is invaluable. Knowing how to configure the peripherals inside the processor, setting the registers, compiling, debugging, loading code, etc..All embedded stuff works this way and doesn't matter if it was your project or a 2 billion dollar satellite in orbit so and you could easily move up to a bigger project if you wanted. As for me, I've been doing this crap for 30 years and freakin' tired of it and want to retire and cut grass or something for a living.


EDIT: I couldn't get the BOV control loop to work right by PWM on both sides of the diaphragm. The "front" side of it leaked through the valve seal and it turned into voodo code that got to crazy. Looked for an IRIS valve but they were way too expensive and got a nice 1" Stainless butterfly valve from eBay and moving to a stepper motor to control it. I'm much more familiar with PID loops on motors that trying to do it with air on the BOV. Just trying to find a way to make the valve easier to open/close (mechanically) to avoid putting in a giant motor in to get all that torque. Jury rigged the leaf blower to this thing and wrote some code to maintain 2psi regardless of blower speed and it worked pretty good....except for the motor stalling because not enough torque.

http://www.ebay.com/itm/122063179557...%3AMEBIDX%3AIT

 

Neat stuff. I'd be interested to hear what that thing sounds like when you have it bleeding off boost once you get it working

 

talk about thinking outside the box. things like this is what keeps peoples combos so interesting.