It probably is tire related and is similar to the "Exploding curbs" that people complain about.
It seems to be that the current tire model does not deal well with two contact patches simultaneously. You get two contact patches when hitting a sharp curb and the tire is still touching the ground and the curb at the same time. This seems to generate a huge amount of energy.
You can test it by by using the chicane curbs on KY3 where you come off of the oval. If you place your car in the right place with it stationary, it will start to vibrate and bounce. I think this is because the physics engine is bouncing back and forth between the two contact patches.
I don't know if the new tire physics will address this problem, or if I even have the problem defined correctly. It could be something completely different than dual contact patches.