In our drag racing, we did use air to fuel ratio as a controlled value to get the engine into a linear range. That task is an extensive explanation through out writings. The linear range is where the engine is completely predictable. We achieved that very well in our racing.

Once we operated the engine in a linear range, we were able to vary our shift point from a Quarter Jr program predictions to get our drag racing ET predictable. A tuning plan was done the day before an outing. Weather predictions from the internet were used. The Quarter Jr program was used to predict the performance with the various air densities that were predicted over the course of the racing time period.

For example, early qualifying was often early in the morning when air density was up. Then later qualifying was late in the afternoon when air density was lower. The different air densities were put into the Quarter Jr. program to get the predicted performance. Shift point was varied to produce the target ET for that air density. In addition I used math that is throughout our writings to determine jetting for the various air densities. Then, with fuel injection jetting and shift point predetermined by the time of day (different air density), I wrote out a plan for jetting and shift point changes.

During race day, I simply looked up the time and my tuneup plan, did the changes, and spent the day eating hot dogs, networking with others, and of course, maintaining the race car. It was a blast and took all the pressure out of tuning on race day. There was simply little to no tuning decisions on race day. And no engine damage from whoops.