Thinking of an air-fuel meter to tune carb - any experience?

[Wbulk]

This subject of tuning a carb with a wideband gauge deserves an in depth thread of it's own. So not to get too far off track I will mention a few things to think about. Before I got mine I read everything I could find on the subject and realized it gave you the ability to do fine tuning beyond in the ballpark tuning, as in the the past from reading plugs. Fuel has changed and varies between areas of the country and is not as easy as it was years ago to read plugs. What I found was that you can fine tune circuits that were very difficult in the past. If the car is moved from one area of the country to another it is unlikely the tune is the same, and no way it will be the same if the altitude is 1,500 or more different.
I live at 5,000 feet and I believe the vast majority of cars that are running an aftermarket carb as this altitude are off. I believe the Youtube video I posted is representative of perhaps the majority of modified carbed cars on the road, except perhaps those run at sea level that most manufacturers tune for.

Be aware that temperature, humidity, and type of fuel all effect AF ratio. If your car is tuned on a dyno at 90 deg. it will not likely be the same as 60 deg.. The same goes for fuel. In various parts of the country there is summer fuel and winter fuel. This can change the AF ratio burn results. The same goes for humidity.

When I shut down my car last October I had summer fuel in the tank and the temp was about 70 deg in the middle of the day. My main metering circuit was averaging just about 14.8. at about 4K rpms. I recently put in winter fuel with the temp in the 50s and ran the car. This time it was averaging 14.2 I know that I will have to check this again when it gets a little warmer and when summer fuel comes out.

Carbs are primitive, but what we can do with a wide band gauge is make the ball park smaller and kind of move it into the infield. Then we are averaging with temp, fuel, and humidity within a smaller area.