DIY Progressive Alky Injection Controller?

[DrFishbone]

Don't know how many might be interested, but I've been thinking about assembling a DIY Alky/Water Injection system for the SC and building my own Alky Injection controller to go with it. Obviously, costs are the main reason for building it myself. Honestly, I don't know much about the controllers that are out there...what functions they have (besides the obvious), what engine speed is the best turn-on, etc. Anyone who could lend some experience on their setup would be appreciated!

I couldn't find any how-to's documented on the interwebs for building a controller for this purpose, but after doing some brainstorming and I think I'll be able to build a simple one for around $20. Basically, it would take the 0-5V MAF voltage and use that to drive the 12v alky pump motor. I plan to have circuitry to allow for an adjustable turn-on limit, and also a "ramp-rate" adjustment.

With the parts I'm looking at now, the minumum MAF voltage that will turn on the pump will be 2 volts - which on my car means a minimum system turn-on at 2000RPM, but I'm thinking of using the injection from 2500RPM+, so hopefully I'll have some good control. It's going to be a challenge to get the pump output just right relative to the MAF curve, but hopefully once that's done on my car, it will be set.

Anyhow, hopes are that I'll have it designed, built, and on the car by the Shootout and I hope to keep the total cost around $100-$120 in parts. (Should make it easier for me to break into the 12's...if the suspension repairs aren't enough....) I plan to share the build in the Member's Only forum, and maybe even build some for people, assuming it's a success. Obviously, tuning the system & EEC to the end-user's MAF curve woudl have to be out of my scope.

We'll see how it goes...if it even actually happens. I did go ahead and buy the guts for the controller, so maybe I'll at least get into the experimentation stages.

[JT's03]

I think I give about $125 for my coolingmist kit brand new. I plan to upgrade the nylon lines to ss one day. I'm running a boost switch and single nozzle if I ever hook this thing back up and tune it properlly. Would like to put a progressive controller on it but havent found any diy on how to make your own. Anyone know of one you should post it

[Mike8675309]

controller is more complex than you can imagine. you will need protection circuits for all inputs, signal conditioning code for the MAF input (can't just tap the line, must do so and not pull any voltage down when you do) and some sort of voltage regulation to deal with the power system to power your device. There are IC's out there that can probably do the job if you code something up and wire in a couple protection circuits.

Assuming you have a controller you also need a reservoir for the fluid, fittings for all the plumbing and a reliable high pressure pump and then the nozzles as well. MAF can work, some might prefer going off manifold pressure (boost).

[DrFishbone]

Originally Posted by Mike8675309

you will need protection circuits for all inputs, signal conditioning code for the MAF input (can't just tap the line, must do so and not pull any voltage down when you do) and some sort of voltage regulation to deal with the power system to power your device.

This is what I was thinking may be the tough part. I know whatever I would come up with cannot affect the MAFV to the computer...o/w...I'd be having some issues.

Originally Posted by Mike8675309

Assuming you have a controller you also need a reservoir for the fluid, fittings for all the plumbing and a reliable high pressure pump and then the nozzles as well. MAF can work, some might prefer going off manifold pressure (boost).

Yes, I've scouted out most of these parts...the pump looks like it will be the main cost...haven't really looked at the plumbing much yet though.

[DrFishbone]

The input impedence is high for the circuit, but still it will take a very small amount of power from the MAF signal...not sure how much though.

Could also look into adding a slot-style MAF...just for the alky controller for now.

[DrFishbone]

Well, now that the rear suspension is rebuilt (MUCH BETTER!), and my wife is mad at me for spending so much time in the garage....now is the perfect time to work on this project again.

I went ahead and bought a couple of chips to build a pulse-width modulator to drive the alky pump and wired it up on the breadboard in the comfort of our living room...still holding off on most of the hardware for now. If the controller doesn't work out, I'll just save up to buy one I guess. Current plan is a Devils-Own pump, tubing, fittings, then hopefully this DIY pump controller to run off the MAFS. I had looked at several different options for pumps, but decided to just get a kit, since it would be compatible with meth too, and the cost isn't that much more.

[DrFishbone]

Originally Posted by JT's03

I think I give about $125 for my coolingmist kit brand new. I plan to upgrade the nylon lines to ss one day. I'm running a boost switch and single nozzle if I ever hook this thing back up and tune it properlly. Would like to put a progressive controller on it but havent found any diy on how to make your own. Anyone know of one you should post it

Where did you get your kit for $125?

[DrFishbone]

Well, got the circuit working!!

I tested it with a 12v water transfer pump and it seemed to work pretty well. Getting it tuned to will take some time, but it does work. The MOSFET in the circuit started getting pretty hot, so it will probably be best to use two with a heat sink.

I wired it so that the duty cycle was varied by a 0-4V dc voltage input. I didn't quite get it to the point where it would turn the pump on 100% though...at least I don't think I did. Didn't feel like busting the oscilloscope out. so who knows.

At this point, I'm starting to be concerned mainly about reliability. There is alot of work on the line that i'm not willing to risk right now using it on the black car Sure, it's a long way from the finished & tested product, but I'm starting to wonder if all the time I would spend on testing and tuning it would be worth it. So unless someone else is interested in the project, it's probably going on the shelf. I still think that it could be built with less than $20 though. still would need to be tested with the MAF sensor used as an input to make sure it didn't screw up the signal to the computer is not detrimented, however I am fairly optimistic that it would be fine.

[DrFishbone]

The motor in the picture is obviously not the water transfer pump.

[Silenced]

Curious to see more pictures of this and maybe a circuit diagram if you have time

[DrFishbone]

Originally Posted by Silenced

Curious to see more pictures of this and maybe a circuit diagram if you have time

http://www.sccoa.com/forums/showthre...756#post998756

Here ya go!

[XxSlowpokexX]

This reminds me of the days I used to build things on white boards from Radio Shack

[Mike8675309]

While 555 Timers work for PWM, they are not ideal due to their high energy usage. If you want help with it I can play with it.

The biggest issue is getting boards made, drilling holes, and populating with components. Then add the cost of the enclosure and you quickly find that any type of production is expensive.

Board size for this could be pretty small which cuts costs. Go SMT with most of the simple stuff, and just through hole for the heat sinks.

I've been playing with micro controllers lately. Here is a multi-threaded example using LED's. One string flashing via PWM while the other being held bright via PWM.

[DrFishbone]

Originally Posted by Mike8675309

If you want help with it I can play with it.

Yez plz.

Can we continue the discussion here?

Just started this thread to spark interest.