Car Tech A to Z - Y is for yaw control

The technology contained within the modern motor car can be both fascinating and slightly baffling. Most such technology exists to make our cars safer, more efficient and just better than ever to drive but some of it can be quite confusing for the average motorist. In this A to Z series we will attempt to unravel the mystery of technology that is the modern motor car. This week, we’re visiting the letter Y…

Y is for…yaw control. Yaw is more commonly – but also wrongly – expressed as roll within the automotive industry. Even though in the aircraft industry – from which the term emanates – yaw describes the pure left to right motion of the nose of an aircraft when that aircraft is otherwise flying dead straight, without rolling, and without pitching.

Either way, yaw is an essential parts of a vehicle’s natural physical behaviour when cornering that needs to be well controlled for that vehicle to feel safe and secure.

Controlling yaw involves most, if not all the different components of a vehicle’s suspension – from its dampers to its anti-roll bars, right through to its springs and even its tyres. Never more so than in high performance cars, where cornering forces are higher and the yaw rates increase as a result.

A car with great yaw control will feel particularly well sorted from behind the wheel during the turn in phase of a corner. Whereas a car with not so good yaw control will feel like it is trying to fall over itself on turn in, which in extreme cases will manifest itself in what’s called turn in oversteer – where the back of the car will try to break away but not because of an application of excess power.

Yaw tends to be controlled mostly by electronics, assuming the anti-slip and traction control systems are left switched on. But you can still tell how well the yaw is being controlled in fundamental terms by switching all the electronic systems off.

If the car suddenly becomes a wild animal then its yaw – amongst many other aspects – is probably not being that well controlled. If it remains fundamentally well behaved with all the safety systems switched off, then the yaw is being nicely kept in check by the suspension.

Next, the letter Z…