Digital Air/Fuel Ratio Gauge Under Development

[Flatland2D]

Yeah, I'm still leaning towards the plastic box. It keeps a nice low profile look that won't draw attention like flashy pods.

[dfoxengr]

youll never get a narrowband to be as accurate as a wideband.

plus there are hundreds of these narrow O2 gauges on the market already, i wouldnt waste time making your own.

[Flatland2D]

If you make a comment that I'll never get a narrowband sensor to be as accurate as a wideband, please give me a reason for your logic other than saying it just won't be accurate. Without justification it means nothing.

Yes, there are many AFR gauges on the market. That's not what's innovative about what I'm doing. Even though the AFR gauges sell for about $40, why pay that when I could build one for $5? The tuning gauges that allow you to read the mix and tune it like my device I've seen go for $240. Add a $0.50 potentimeter to my unit and update the code and now you can adjust mix. Now say if I got the wideband simulator feature working, no other device on the market does that.

Besides, I think running more lean will yeild a higher increase than switching from narrow to wideband.

[GasSavers_Diemaster]

if u want me to help test this out i can. u'd have to send me a programed chip as i dont have a burner yet. BTW my MPFI swap i put in a brand new O2.

[dfoxengr]

narrow 0-1v
wide 0-5v

this is for the O2 sensor.

get a bosch LH1 wb sensor, from a 92-95 civic vx and you oculd make it work.

[Flatland2D]

I said I'm simulating the characteristics of a wideband sensor, I'm not saying I am making one out of a narrowband. Differences in voltages between the two signals is competely irrelevant. I'm talking about dampening the narrowband signal so it doesn't overshot stoic. ratio everytime, like a wideband does. Now did you read what I wrote about DSP? I explained every detail about how this will work. I don't think there's anything else I could say to clear things up.

[dfoxengr]

its clear, but it wont be 100% as accurate

[Flatland2D]

I don't believe I ever said it was going to be 100% accurate. Any simulation is not as good as the real thing.

I have no idea how much more mpg you get with a wideband, but lets say it's about 3mpg and my simulator feature is 66% accurate. That's still a gain of 2mpg, which I'd be happy with considering the extra 1mpg of using the real thing is going to cost $150.

[krousdb]

Originally Posted by Flatland2D

I've created this thread to document the status of my AFR gauge project. I will update when advances in design are made.

Tonight I completed the first step in developing a microprocessor-based AFR gauge. Use of a programmable chip allows for easy manipulation of the signal and analysis. It currently reads a signal from 0V to 5V and outputs it on a 10 segment LED bar graph. This is analogous to the 0V to 1V signal produced by the oxygen sensor - all I have to do is change some numbers around in the code.

The next version will incorporate a tuning function that will allow the driver to scale the O2 sensor up or down, effectively making the engine run lean or rich. Running lean should allow for large mpg gains. I'm hoping this will really come into play during constant speed highway driving when acceleration is not needed.

I was also thinking about adding a wideband simulator feature that would basically allow your cheap narrowband sensor to output as if it were a $150 wideband sensor. This would also benefit fuel economy.

I plan to test the inital version (just the gauge) this weekend if it isn't too stormy from hurricane Rita.

The final product will either be released strictly as plans or possibly for sale as completed units through this site with the approval of Matt.

How are you coming along on this? I would love to have one of these.

[SVOboy]

Remind me tonight and I'll get you some instructions to make one of these, , they're no good but they might give you an idea of rich/lean, not that you can do anything about it.