DIY Electronic Tuning / Gauges

[Enigma_Man]

Hello all. I'm sorta new to this board, I've just been lurking for a few months now. Anyway, to the point: I really like designing electronic gadgets and stuff, I want to make my car go faster, and I'm poor. So, while I'm saving up to buy a 16g to replace my dead 14b, I want to see if I can get some projects going, and I'm wondering if anybody else has or has info that could help me out.

What I want to build eventually is something like a combination VPC/AFC, that replaces the MAF, and also allows finer tuning of the signal.

I'm also looking into Wideband O2 sensors, and a gauge that reads the ECU diagnostic port signals (like logging... but without the logging) I saw someone online that had made a Knocksum/timing advance meter, but I can't seem to get into contact with him.

So, if anybody has any info that could help me out, or be interested in collaborating something, let me know. My e-mail is [email protected] if you'd prefer to mail me personally about it (yes, that is my real address).

-Jesse

 

[ArtOfSpeed]

What you propose, my friend, is an uphill battle. There is a reason that the VPC sells for 1K. The electronics themselves are not terribly dificult, but the code is. I built up a breadboard of one that I was playing with for awhile. It used a Atmel CPU and Maxim A/D convertor to get it all in and replicated the MAF output signal with a Maxim voltage to frequency convertor.
Obtaining a 5v squarewave with a 50% duty cycle that varies from 30 to ~2500 Hz was a real bugger. Tuning the maps effectively to take IAT, MAP and Baro pressure into account was just plain stupid.
My original plan was to log the MAP and the MAF under the same conditions to get a basis to compare from, but work got busy and I never got back to it. All in all it is just simpler to buy a used VPC and call it a day. Unless, of course, you have a dyno in your garage and a spare engine to destroy...
Good luck!

 

[ArtOfSpeed]

Whoops...
On your other points...the Pocketlogger is a really nice tool. I know awhile back I saw an MPG of a digital display he was working on that did what you are talking about. Maybe contact hiim on that.
For a wideband, look into the OZ DIY wideband. You get the full kit with display and cases for $200 USD, and the O2 sensor will set you back ~130. Not bad, all said and done.
Feel free to e-mail me offline if you want specifics on anything. I'll tell you all I know (which isn't that much, but if it helps...=)