Autometer A/F gauge question

mbaird said

I am curious about why you think it will be worthless for tuning purposes. You should at least be able to get a good baseline for the cruise, power and idle jettings.
I have my collectors set up with bungs and was planning on doing just what Superdart is talking about. I would spend $200 to avoid 3 days of trial and error tuning ,
not to mention pulling plugs out of hot motors for readings.

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#1 - If your narrow band O2 sensor is working properly, and the mixture is in the right ballpark for 14.7:1 stoich ratio, all you will see on the gauge is the LED bouncing wildly between rich and lean.

#2 - If the miture is too rich or too lean, then the LED's will go to one end of the scale. The problem is the NB O2 sensor cannot accurately tell you by how much the mixture is too rich or too lean.

#3 - You have absolutely no way to record any readings from the gauge. All you have is the visual indication. Do you want to take a 1/4 mile blast with your eyes glued to a gauge? I don't want to be in the lane next to you if you do.

If you are willing to spend $200 for a NB O2 sensor and a bouncing LED gauge that won't tell you much, go right ahead. But for another $100-$150 you could get a true Wide Band O2 sensor that can provide some very accurate data.