The whole car in a corner

Weight transfer, roll stiffness, tires that get worse as you lean on them, and the one number that describes balance.

1. Weight transfer: the master equationHow much load moves to the outside wheels in a corner depends on four things, and springs are not one of them. This single fact kills more suspension misconceptions than anything else in the course.
2. Roll stiffness distribution: the balance knobThe total load transfer is fixed. How it splits between the axles is not — and that split is the most powerful understeer/oversteer adjustment on the car. It's also why the anti-roll bar is the cheapest tuning part you own.
3. Tires: load sensitivity, and why grip isn't a coefficientPress a tire harder and it grips harder — but not proportionally. That single non-linearity is why load transfer costs lap time, why balance tuning works at all, and why four evenly loaded tires beat two heavily loaded ones.
4. Understeer gradient and the skidpadOne number describes a car's steady-state balance: how much extra steering it needs as lateral acceleration rises. And a car can be perfectly neutral at 0.3 g while oversteering at the limit — which is the setup in this app.