Dave Kaemmer has written up and excellent explanation of what is coming in tire modeling from iRacing. I’ll warn you now, it’s full of physics and mathematics, however if you want to understand just how difficult it is to get right, you should have a read HERE
If you are new to physics and would like an overview of how it works in relation to racing simulations, I’d suggest reading up on “The Physics of Racing” first. There is a copy here
I’ve been enamored with physics and how it relates to cars for a very long time and even started writing my own game at one point. The interesting thing is that there is so much that is known, suspension geometry, shock physics, that is straight forward to model. (I try not to use easy) A lot of black box physics engines can do most of that stuff to varying degrees.
The tough part is the tire physics, mainly due to the secretive nature of the business. There is also the fact that a game / simulation will take the tires much further over the edge than even the tire companies test and that is a black morass of fuzzy logic and out of the box mathematics. Why? Well mainly due to the existing formulas for calculating forces acting on a tire at the edge explode in corner cases when they get over the edge making the math get all sorts of crazy.
Have a read of the excellent articles and post your questions. I’m thinking I might dive back into it a little to at least be able to answer questions. There are some open source basic looking physics engines around that I also might have a re-look at to show how it works in code … if anyone is interested of course.