D.I.Y. air/fuel ratio meter

I dont know if this is sticky worthy or not, but I figured this would be really usefull to anyone who knows how to do basic circutry. I have yet to do this myself but it is simple enough for me to do, and I never have "created" anything like this. It just requires some soldering expierence, and if you dont have that you can easily access tutorials online on how to do so.

If you have a carbuerator you need to take and get an o2 bung welded onto your exhaust near the down pipes.

Im pretty sure you can splice the wires to your existing o2 sensor if you have one. *someone correct me on this if im wrong, maybe the voltage drops because of the extra sensor, im not sure*

The link explains it pretty much in a detail that will get it done if you do it properly. This doesnt seem that hard to do and can be extremley usefull for carbuerator tunning and even for the "cool factor" along with many other things. You dont have to enclose the unit inside a box like that, you could fabricate it into your dashboard or anything you can think of.

Ill be doing this once I get my car on the road, I plan on buying a new carbuerator so im going to use this for tunning purposes. Its cooler if you do it yourself than going out and buying one

 

The only problem is the oxygen sensor isn't very accurate at all- I'd say it's only for the cool factor. The sensor itself isn't accurate- small changes in a mixture wont be displayed. I wonder what installing a wideband oxygen sensor will do with that circuit. I used the 3914 chip for numerous other gauges with great results- makes a good quick reference for all sorts of parameters.

 

"You must understand that using stock lambda probe you won't get accurate air to fuel mixture readings. For engine tuning special wide band lambda probes are used."

 

I was responding to what you posted:

 

Right, I guess its not as usefull as seeing it as a number.. 0-2 volts being represented by 10 led's total, not too accurate. The a/f meters that you can buy with the digital readouts are the best. So I guess it is just for the cool factor.