They are many things that coulb said of the impact of the rain on F1 races. Let’s start.
Rain makes F1 races more dangerous by changing the aerodynamics and the grip of the car, by reducing visibility and by increasing the risk of aquaplaning. Teams will try to cope with these changes and risks by changing the setup of their cars such as the type of tyres, the suspension’s stiffness or the front-rear brake bias.
Rain makes F1 cars go significantly slower. Races can be longer too since cars are slower and often when there is too much water the race can be suspended. This happened during the 2011 Canadian Grand Prix which lasted nearly 4 hours and is the longest race in history. Lastly, the rain evens the field between drivers. It makes overtaking much more easier by diminishing the technological differences between the teams.
Now, there is much more to cover about F1 and rain so keep reading.
The Impact Of The Rain On Speed And Lap Time
Obviously, an F1 car racing under the rain is going to be much slower. This is due to several factors: lack of visibility, risk of aquaplaning, wet or intermediate tyres that impact the grip of the car, etc. What is actually the speed or time difference between a car racing on a dry track compared to a car racing on a wet track?
Let’s take Monza for instance. On the Italian Grand Prix the best ever lap was made by Kimi Raikonnen in 2018 with a lap time of 1:19.119. On the same Grand Prix during the free practice session of the 2019 season, the best lap under wet conditions was made by Valtteri Bottas with a time of 1:30.596. This a 10s difference on one of the shortest tracks on the calendar. If we take the same calculation but this time on speed, on dry conditions the average speed on Monza is approximately 260 km/h (162 mp/h). On wet conditions it is 230 km/h (142 mp/h). So this is a severe decline in speed and lap time.
With the decline in speed, it may seem that racing is less dangerous under wet conditions, but this is far from the truth.
How Dangerous Racing Under The Rain Is
Racing under the rain is slower, yes, but it is also much more dangerous than racing in sunny weather. This is due to several factors.
F1 cars are designed to be driven safely within certain conditions. The brakes and aerodynamics of the cars work best once the car has a certain speed. Paradoxically, it is when the car is too slow that an F1 car is the most dangerous. For instance, with the wet and lower speeds, the rear wing does not work very well. This result in less downforce and more difficulty to turn. The tyres are also changed for wet or intermediate tyres with a worse grip than slick tyres. Both effects make turning difficult under wet conditions.
That is not all, the question of visibility is very important. The visibility is highly reduced by the spray coming from the car in front and by the drops of rain on the helmet of drivers. It is so bad that one time, the 2009 World Champion Jenson Button, said that once he drove an F1 car in the wet he looked at his fellow pilot colleagues differently seeing that they were all insane. Worse than what Button said, one time, Kubica overtook Heidfeld during a wet race without even realizing that he overtook him…
There is more, obviously the more standing water there is, the more there is a risk of aquaplaning. This is also a critical parameter when racing under the rain. The speed is slower, but the aquaplaning and all the effects above make the rainy races very accident-prone. In fact, the last F1 drivers who died while racing was Jules Bianchi. The Frenchman died while racing in Japan under the rain while going at a very low speed.
Teams try to adapt the best they can in order to adapt and change their settings. The aim is to get the best performances from the car while under the rain. Let’s talk about F1 car setup under the rain.
F1 Car Setup On Wet Conditions
First, the tyres are changed when racing in the rain. Wet or intermediate tyres are installed on the car instead of the slick tyres. These tyres offer less grip that the slick tyres but are specifically designed to evacuate water while driving. The aim is to raise the grip as much as possible under wet conditions. Wet tyres are also heavier, this affects the load distribution of the car and reduces the ballast placements. It also raises the height of the car. This is useful as F1 cars are very low, it allows them to be above the standing water on the track.
Secondly, front-rear brake bias is moving rearward. Since there is less braking grip, there is no need to have the brake bias as much forward. Otherwise, the front brakes will lock too easily. Thirdly, since there is less lateral grip, teams tend to go with slightly softer suspensions. With less stiff dampers or bars for example. Lastly, the temperature of the engine and of some other systems are adapted to work in a cooler environment.
Now that all is clear about the setup, lets talk about the what actually happens during the race.
Race Management And Strategy Under The Rain
Knowing all that we already shared above, it is clear that visibility is of the essence. Starting in pole position is even more important when you see not so much during the race. The rain makes the qualifying session unpredictable. Let’s say we have stormy weather, but few moments of sun are expected. With the difference in speed between a wet and dry (or less wet) track, some teams will try to launch their drivers during the sunny window to be quicker.
Drivers will also try to warm their wet or intermediate tyres in order to use them at their ideal temperature range. See this post we made that explains it all. Basically, the tyres need to be in a certain temperature range to be fully efficient.
During the race, it is also easier to overtake while it is raining. The rain evens the field. Drivers’ racing skills become more important than pure car technology. The great Ayrton Senna once said :
You can not overtake 15 cars in sunny weather … but you can when it is raining.
They are great examples of surprise wins or poles under the rain. There is the famous 2011 Canadian Grand Prix where Jenson Button went from last to first in 30 laps under the rain. There is also the 1984 Monaco Grand Prix where Ayrton Senna started 13th on an uncompetitive Toleman and finished 2nd just behind Prost.