any road race guys on here

[GMC70c20]

I recenetly read the book "racing and high performane tire" which was a great book but I need to know how you caluclate lateral force? I understand how slip angle itself (and when compared to lateral force) works but what I'm confused about is how you actually apply it to a car. I would think if you could calculate lateral force then you would have one side of the graph and then would know how much load to put on the tire before its to much. This isnt for my truck a friend of mine just got his car back from the enigne shop and we were going to start playing with it.