Anyone have any links on how to do this? If not, I will figure it out myself, but any information anyone has will be helpful.

-martini
93 Mazda RX-7 (The street race car)
90 LS/VTEC CRX Si (The track race car)

 

It all depends on what you are looking for. If you want functionallity then it is simple. If your goal is to do some hardcore Boulevard Pimping and "impressing of tha ladiez wif your mad teknowledgy" then forget it and just buy one.

If you want to make one for functionallity the simplest most rudamentary way is to go to Radio Shack and buy their $20 DVOM (Digital Volt Meter). You can either:

A) Patch it into your O2 sensor signal leads

B) Get an O2 sensor flange and weld it on to your exhaust then get a second O2.

If all you are looking for is the data then this will work fine because it will tell you exactly what you need to know far more precisely than a swinging LED display will. If on the other hand you don't care and you just want the lights buy an EQ for your stereo instead - it will have more purpose. On the flip side, unless you have some adjustability in your system ie: Programmable ECM, Adjustable FPR etc. There really is no point in having a Halmeter because you can't do anything with the data you get.

 

Try this:
http://www.diy-efi.org/diy_efi/proje...ED/O2_LED.html

You can get free "samples" of LM3914 chips from national.com if you sign up. They send them 2nd day air, too

Dustin

 

If you go the voltmeter route- the sample rate will be very low and you may not see the actual "A/F ratio".

 

well, essentially, I would just have, maybe 9 leds, 3 red, 3 yellow, and 3 green (from lean to rich). Very similar to the ones that are sold by autometer or whatever. I'm not interested in paying for an autometer guage. And no, it's not for "pimpin", it's for function. It's a race car. Stripped out, fabricated aluminum instrument panel. Thanks for the help, keep them coming.

martini

 

I've made a simple one that works just like the autometer, which is not all that helpful really. I used a 10 LED bar graph from radio shack, but if I did it again, I would probably use 20 or so. It's calibrated well, from 0-1 volt, and I added a small capacitor into the input signal to condition it and slow the dancing lights and make it more readable. And if you want real accuracy, you will need to calibrate it to a tighter scale; and since yours is a race car, you may want the low to be .3v or .4v.

Try these sites:
http://www.scirocco.org/tech/misc/afgauge/af.html
http://saturn.spaceports.com/~miata/...myO2sensor.htm

email me if you have any questions,
Greg