How Exactly Does Damage Affect a Formula One Car?

Lewis Hamilton lost around 35 seconds to his teammate, Valtteri Bottas, in around 20 laps during the Austrian Grand Prix. Needless to say, this isn't normal, and oscillating loads from those infamous Red Bull Ring kerbs was to blame as Lewis suffered damage to the rear of the car.

But what exactly does this kind of substantial damage do to a car, and why is it so significant despite not being race-ending?

Image sourced from @Flyin18T

Image sourced from @Flyin18T

In this particular case, the damage was incurred in the most sensitive part of an F1 car, aerodynamics-wise. The rear is where most of the downforce is created, and indeed most of the front of the car is used in preparation for it - the bargeboards and front wings don't really create a huge deal of downforce themselves, instead they produce vortices and direct air to optimise the suction effect that happens at the back of the car.

Therefore, the worst place to damage the car is the rear; and immediate loss of downforce is the first, most obvious effect of damage. This will lose you lap time and confidence.

Off of this immediate loss of downforce branch many other issues, one of which being the movement of the centre of pressure. The centre of gravity, as you may know, is where you can assume most of the mass of a body is concentrated. In an F1 car, it should be biased around 60% towards the rear seeing as the heavy duty components such as the engine and gearbox are located there. The centre of pressure is a similar measurement, but obviously this time it involves pressure distribution.

The location of both of these centres is critical; race cars must have their centre of pressure behind their centre of gravity, otherwise the car becomes impossible to handle. Even in straight lines, tiny disturbances will pull the car sideways if the centre of pressure is in front of the centre of gravity.

The W08; a car with a visibly low centre of gravity. @LateBrakers

The W08; a car with a visibly low centre of gravity. @LateBrakers

The distance between the two is called the 'static margin', and by damaging the rear of the car the COP moves forward, reducing the static margin. This moves the balance forward and renders the setup incompatible with the track and its conditions. Again, the handling worsens.

Now we get to the overall efficiency of the vehicle - and like everything else, it decreases with damage. With less downforce, the tyres have less force acting vertically on them, pushing them into the track. This decreases their friction coefficient, i.e. how much they can stick to the track, and augments tyre slip. Tyre slip is the difference between the tyre's direction of heading and direction of travel, which basically means how much it slides.

More slip equals more sliding which equals more wear. This in turn snowballs into more sliding, increasing temperatures and wear until the driver is forced into radical tyre saving.

@Flyin18T

@Flyin18T

A way to try and alleviate this is during the pit stops, and indeed during Hamilton's case, Mercedes added a huge nine clicks to his front wing. This will increase the angle of attack of the front wing elements, adding downforce with the penalty of drag to try and claw back some lost aerodynamic performance. This actually did very little for Hamilton; he was much slower after the pit stop which highlights just how much worse it could have been as a result of all the aforementioned effects, had the pit crew not made this substantial adjustment.

Fuel is another problem; with the damage you become much less efficient, and this leads to more lifting and coasting to rob you of more lap time.

The driver's mentality is the final department that suffers, they'll almost certainly lose confidence - and with it, cornering speed.

@LAT

@LAT

Moral of the article? Don't damage an F1 car!