Hello there!

I am Yanna and I am building a racing car. I am now trying to calculate the tire drag of this car when cornering, but I'm stuck on something.

In order to find the tire drag, I need the normal load on each wheel. To find this, I made some equations:

1) the sum of the normal load over all four wheels equals the total gravity force;

2) the sum of the momenta around the Center of Gravity in pitch direction is zero;

3) the sum of the momenta around the Center of Gravity in roll direction is zero.

However, I now have 3 equations and 4 unknowns, so I cannot calculate the normal load on each wheel. What should the fourth equation be? I have some ideas:

a) The sum of the momenta around the Center of Gravity in yaw direction is zero;

b) Some equation regarding the torsion of the car being zero. (I would not know how to make this equation)

Is any of these ideas correct or is it another equation that I should use?

Thank you in advance for your help!