Staged extra Injector control + other goodies design. Input wanted

[Joryn]

Hey all, This is a project that i've been kinda sitting on for a while. And in some ways is similar to the one that Carl (DblTrbl) had built a while back. With some improvements in mind of course

Anyways here's what i've got in mind. I'm thinking of running up to 4 Extra injectors in my setup come spring and that's a few too many to just turn on with a pressure switch. Not only that but its just too much fuel all at once really. So i figured i might as well put this Electrical Eng degree to some good use for the TD community and spend some time working on a Extra injector controller thats custom built with Us in mind.

The basic idea is that i wanna use an electronic pressure sensor, microcontroller, a couple taps into the basic electronics on our cars (O2 sensor, TPS, Map etc) and based on the input from those stage and control the firing of the extra injectors.

As a bonus of this setup since we have a pressure sensor on board with a Micro we can have A/F monitoring, electronic boost monitoring, a custom built A/F gauge and whatever else we can dream up (micro's are awesome imo ).

I know a number of people have looked at doing this in the analog realm and I'm not sure how many have done up something like this but I did a search and couldnt find much. So there it is.

What i was needing from you was input into what all I could reasonably integrate into this project in the way of monitoring and control, within reason of course heh. so hit me with any little dream you've had in the way of a custom built EIC (maybe EBC if i get reallly creative) and I'll start thinking of ways to build it, within certain cost limits as i am currently and Unemployed EE heh.

I hope to get some good feedback going so let the "fun" begin

[Joryn]

Ok, maybe I was wrong in thinking that this was something that was wanted, or maybe I'm just not being clear enough in the description. What I'm basically saying is that I can probably build a Budget electronic fuel management system for an Extra injector type setup. Also possibly incorporate electronically controlled boost. But before i start nailing things down i need/want Input here!! Cmon guys, just for the heck of it list something you'd like to see done in the way of a boost controller, EIC, gauges whatever and ill see what ican come up with

[altered7151]

Sounds like a great idea, I personally would love to have an affordable electronic boost controller. I think the only problem you might run into with selling them is if they approach the price of a custom cal people might go that route, Since the whole point of the extra injector was the cheapness of it. But unit that controls boost, displays a/f ratio, and controls extra injectors definitally sounds like a nice piece to me!

[beefalobilly]

yea, doesn't have to be too complex, and considering a custom 3-bar cal can be had for a pretty good deal it cna't be too expensive either, maybe even provided as a kit for those who like to solder

[Joryn]

Yeah i wasnt so much looking into selling them as I was looking into just designing something that everyone could use. The whole point of this exercise is to try and keep the price down but there is a few things that this little project will have that the Cal's wont

First off it'll be adjustable, and very easily adjustable at that. You'd be able to tell the setup when you want those injectors turned on based on any number of variables that this thing will monitor. Same goes for the boost control (now this section i think could be harder as the hardware to do adjustable boost control electronically is a bit pricier. I'm going to ahve to get creative on this one). this idea is basically for tunability, and its also flexible in ways that a Cal may not be.

I'm gonna spend today brainstorming some ideas as to what all i want to get done, and see if i cant nail down a requirement specification out for you all

[beefalobilly]

cool, i'm very interested, i'd be interested in helping except i only have one year of high school electronics...although i want to take some more in college

[cadmanspd]

Carl's looked very useable. Even something just a little more complex than that would be very useful. I know I have a picture of his plan to make one myself. The extra injector route is such a wonderrfully inexpensive way to crank up the boost.

[Joryn]

OK, it's good to know there is at least a bit of support on this. I'm going to need some help in this as well. Mostly in the area of figuring out exactly how each sensor in our cars react, how quickly etc. I'm going to try and get a overall summation of all the things i want to include (not sure if All things i want to do will get done but hey why not at least try right?) and hopefully that might generate some more interest.

Keep the input coming everyone

[beefalobilly]

http://minimopar.knizefamily.net/ecu/index.html
Have you been here? It has a description of all the sensors and what they do how they work etc, might find it useful

[beefalobilly]

http://minimopar.knizefamily.net/perf/eepc.html
here's the other part i was looking for...he has some great info here too

[crazy1eye]

Sounds like something I have for sale http://td.rcwebdev.com/forums/showthread.php?t=65179

It starts injecting at 12psi & increases as boost & rpm increase, works well. It originally sold for $450 back in 1990.

[Joryn]

Heh, nice little tool there Patrick, Yeah i knew that there were some AIC systems out there done not bad. But nothing really TD specific. give me a few days here and I'll hopefully have something interesting conceptualized.

this past year i was actually working on a 4th year Design project to design some digital gauges with quite a few features, including datalogging and all sorts of goodies. I plan on using what i learned in there on this project as well I think this thing has a lot of potential, if i actually motivate myself enough anyways heh. so keep watching this thread

[AZTurboMini]

Variable fuel rate based on boost psi would be nice.

[Joryn]

Quote:

Originally Posted by AZTurboMini Variable fuel rate based on boost psi would be nice.

Yeah i was thinking about that. And it actually would be really easy, but I'm wondering if it's worth it. Simply based on how long it actually takes boost to come on once you start getting around the 15 psi mark the fuel rate would come on to max in virtually no time flat. But i guess its something i could mess around with.

But if we do decide on something like that it would be kinda cool to pulse the injector with a low duty cycle at first (when it starts to break the boost threshold the stock system can manage) and then bring it up to 100% as the boost continues to rise, once at 100% it fires the next injector in a similar fashion. But like i said this would all take place in like less then a second so perhaps not worth it?? What do you think?

It might be more worth it as part of a 2 stage or 3 stage boost system. Off the line you run around the stock limits (launch at 13 psi to minimize spin) then once the speed comes up switchs to a higher boost level. Not sure if lowering or increasing the boost part way down the track would help anymore but it could be fun for tuning

[stampederunner]

I am very interested in seeing what comes out of this! Please keep us informed.