Vehicle’s Dynamics – Episode 1

27 May 2016 Redazione Techniques and Driving

A car, as logical, it’s a body occupying some volume in space, and so it is subjected to different physical laws and forces: centrifugal, centripetal, gravity and kinetic energy. Briefly, in this episode, I will give you an overview of the forces that can vary the stability of your vehicle while running, then deepen in the following episodes.

In this case I am not referring to the classic oversteer and understeer, but I’m talking about body roll, pitch and yaw, and then we’ll analyze how it is produced and how much weight transfer may be useful or dangerous. The ROLL happens when the car tends to lie in the opposite direction to the bend angle you are facing. If for example you’re steering to the right, the car will tend to lean on a longitudinal axis to the left: this is because of its dimensions (height, width, length), its weight and for the type of suspension (height, rigidity). The PITCH is instead a rotational motion that tends, in other words, to vary the ride height of the nose (front axle) or the tail (rear axle). At relevant speed or when braking, maybe even while you are preparing a corner, the pitch becomes so dangerous, because changes the distribution of loads. The YAW is finally represented by a rotation of the car body on its vertical axis passing through the center of gravity of the vehicle. Very dangerous, it can lead to a complete loss of control of the car.

In the next episode, we will analyze the 3 points that we have briefly listed and find out a little more about how to use the weight transfer to our advantage.

Words by Carlo Brema