- Valtteri Bottas elegantly demonstrates a plume of spray.

Could F1 cars be designed to race in the rain?

Jean Todt intends to create cars "that can be driven in the rain" in the next technical regulations overhaul in 2025/2026.

3w ago

Today I was looking through the comments of a certain Instagram post from a well known publication, which stated Jean Todt's intentions to create cars "that can be driven even in the rain" in the next technical regulations overhaul in 2025/2026.

What I saw was a general consensus of Todt's comments being nonsense, and perhaps suggesting an effort to disguise the farcical events of the Sunday of the 2021 Belgian Grand Prix - a race lasting an unclear number of laps (a number definitely lower than five) behind the safety car before inevitably getting called off for good.

However Jean Todt is looking in the right direction here in terms of at least trying to make racing in extreme wet conditions possible. Of course it has to be safe to do so, so meticulous and guided research by individuals and groups who know what they're doing is the key to finding answers.

In qualifying at Spa, probably one of the sketchiest sessions F1 has ever seen with how much minimum apex speed contemporary F1 cars carry through most of Spa's corners, the notable incident was Lando Norris crashing heavily at Raidillon after losing the rear just after the compression of the Eau Rouge/Raidillon elevation change. The front suddenly gripped up in a way Norris was simply not expecting which instantly rotated the rear with absolutely no hope of the driver retaining control. Therefore this seemingly wasn't the fault of aquaplaning - and drivers seemed to agree as the complaints made over radio and in the TV pen post-sessions was that of poor visibility (which of course is amplified in a race scenario the next day where cars are close to each other unlike a fast qualifying lap).

A portion of the gigantic plume of spray produced by current F1 machinery at full chat is generated by the tyres and the water displaced by the contact patch with the tarmac. As the wet tyres rotate, water is pumped sidewards at 85 litres per second (at 300km/h) according to Pirelli. So logically decreasing the contact patch by introducing thinner wheels and tyres, or maybe even running higher pressures, will solve the problem - unfortunately not as it'd simply lead to an exponential rise in aquaplaning.

Once cars begin to aquaplane, especially in a straight line, the session must be instantly red flagged. The drivers are no longer in control of their destiny and no amount of skill can prevent a serious incident.

A way of reducing aquaplaning is to raise the ride height, but this will only reduce the likelihood of the floor of the car riding the water and lifting the tyres off the ground. It won't prevent the tyres simply beginning to float by themselves especially as the intermediate and wet tyres do already enact a slight change thanks to their slightly larger diameter than the dries - raising the whole cars' ride height by a small degree.

Perhaps a further increase in ride height by increasing the size of the sidewall (or the wheel itself) of the new 18-inch intermediate and wet tyres could be a quick solution in coping with extreme standing water.

Mudguards or wheel covers like that in which Gen 2 Formula E utilises will most likely make next to no difference to the spray and subsequent issues experienced by the drivers following behind. A larger proportion of the spray than you might imagine is actually generated by the aerodynamic surfaces of the car. Specifically the underbody and diffuser, and the leading edges of larger appendages.

The low pressure area that designers are eager to optimise sucks up the water and throws it skywards out the back of the diffuser. With the leading edges of the diffuser and rear wing only amplifying the problem by creating brand new vortices to spin the air and water ever higher. The higher the spray is forced up behind the car, the longer it lingers at eye level around the circuit.

Effectively the plume of water you see trailing the cars is the 'dirty air' concept that F1 is so desperately trying to quash with the revamped 2022 technical regulations. It's always there - and wet weather running is a good visual portrayal in showing why drivers following behind another car in dry conditions find it nigh-on impossible to overtake without at least a two second per lap advantage.

So if the 2022 cars deliver what they promise then wet weather visibility should improve by a noticeable margin next year, but I wouldn't expect a staggering improvement. And with the threat of climate change casting a shadow over the world, the likelihood of further wet races encroaching on F1's previously bulletproof calendar, safety measures and broadcast slots can only increase.

The reality of competing in an outdoor sport in multiple time zones, throughout a whole year, is there will be scenarios and conditions that are impossible to avoid, preempt, change or cater for. The fact of the matter is the conditions on the Belgian Grand Prix weekend endangered drivers, marshals and fans. So not releasing the 20 cars was the right call, but hopefully research and evaluations can be undertaken for the future.

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Comments (8)

  • Another big problem is the tyres and tyre temperatures (although it’s also part of a larger problem of the Pirelli tyres), you can gain extraordinary amounts of time if your tyres are in the window in the wet (see George Russell’s P2 lap), but it can be undriveable if the tyres are too cold; which is usually the case.

      26 days ago
    • Yeah indeed. That's one of the arguments for letting them race at Spa, or at least doing more laps behind the safety car. But it's pretty much impossible to work any reasonable temperature into the tyres in those kind of conditions at slow...

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        26 days ago
  • Easy. Add some wheel arches and mud flaps. Or those carpets that they put on some Juggernauts.

      25 days ago
  • Have a wet weather car, different regulations designed to run in wet weather only, make it as simple as possible and let the teams figure out what works best, cost capped of course. Have them submit a "wet weather" car designed at the beginning of the season with only small upgrades/changes allowed from year to year.

      24 days ago
  • Tyres and temperatures would be key. JT is on the right direction, as rain races do make for eventful races. Next would be colder and icy conditions, they can race all year around...

      24 days ago
  • They were

      25 days ago