F1's new 2022 aero rules — by the man who drew them up

As F1 prepares to embark upon a brave new era in which the cars are specifically regulated to provide closer wheel-to-wheel racing, Pat Symonds, the man in charge of formulating those regulations – a process stretching over five years – gives us some insight into them.

The object of these regulations has been to address the overtaking difficulty that has plagued F1 for a couple of decades. Symonds was recruited by Ross Brawn to attack the problem on behalf of FOM (Formula One Management) and commercial rights holder Liberty. He had his own staff, working with FIA technical chief Nicholas Tombazis while F1 teams made various resources available.

As Symonds explains, “This is first time that a set of F1 regulations has been the result of full research. Limited research was done for the 2009 rule changes but in the off-season most people had overcome the limitations they imposed, rendering the regulation change pretty ineffective before we started.”

Motor Sport: The overwhelming outcome of this latest research seems to be the need to keep the aerodynamic wake of the car narrow.

Pat Symonds: “Yes, with the previous cars we had the Y250 vortex between the nose and the wing elements interacting with the barge boards, producing a quite strong outwash which goes outboard of the rear tyre. That’s been the preoccupation on these [previous] cars – to get that outwash as far from the centre of the car as possible to enhance the underfloor performance. But it creates this very incoherent wake behind the car which destroys the aero performance of the car behind. When you look at the ’22 car, we keep the streamlines very coherent and almost all of the wake is fed inside the car. Only a little bit escapes around the outside of the rear wheels.

“We’ve regulated little turning vanes which are effectively vortex generators which use the difference in pressure across them to train the air to the floor. Even the air which does manage to get outboard of the rear wheels, we are able to bring it back in again.

“Currently the teams are even using the diffuser to outwash, because that creates a pressure outboard which pulls the dirty outwash air along from the front of the car and prevents it being pulled inwards at the back.”

Replacing the ‘flat floor with diffuser’ with long twin venturis within the floor has meant a greater proportion of the total downforce being generated by underbody rather than over-body. What else has it done?

PS: “In the previous car you have this very wide low-pressure area directly behind the car at the height of the front wing of the following car so it’s very hard to get out of it. If you move sideways it’s still there. With the ’22 car the whole idea is we push everything together and it then gets lifted up, creating a big mushroom shape, lifting the wake high in the air. The flow surfaces of the upper body and the venturis in the floor are all contributing to this effect.

“It means that the air at the height of the front wing is relatively high in pressure, letting the wing work much more effectively – and that goes all the way down the car. You lose far less efficiency when behind another car.

“But the numbers are so good. Even when the teams get hold of them they’ll still be very good – though not as good as on our car generic because they have different motivations.”

Will the front/rear aero balance be different to that of the previous generation of cars?

PS: “Only when behind another car. In isolation we have balanced the ’22 car the same as the current cars. I wanted to push it back to move the wake backwards – for two reasons. 1) I think you can design a lighter car with a more rearward weight distribution, and 2) more rearward aero distribution means less front wing. Therefore you get into less trouble when following. But the teams really pushed against it. It was quite ridiculous. We put a maximum wheelbase of 3.5 metres, and one team said it was absolutely impossible to get below 3.65 metres. I happened to work for that team a little while ago and I asked them to have a look at my last car there and see what the wheelbase was: Oh yeah, 3.56 metres. So it can be done!”

Wasn’t the initial intention to limit the front downforce by regulation and thereby limit the total because of the need to keep the front/rear aero balance?

PS: “It was more a case of the front being much more affected by the rear of the car ahead so let’s not use the front of the car so much. In terms of the total amount, we delivered the teams a car with a co-efficient of lift of 4. If we’d gone any higher, by the time they’d developed it it would’ve been too quick. So our thinking was if we delivered 4, by the end of ’22 they’d be about where they are now, which is towards 5, a bit over 5 on the very top cars. From what I hear I think they might get there by the start of the year.

“When you have a mature set of regs like now, I know you find about 1 point of downforce for every 100 runs you do in the tunnel. With a new set of regs maybe 3,4,5 at the beginning because of the low-hanging fruit – and then you come down slowly. Ten points of downforce is about a tenth of lap time.”

Will these cars be more demanding to drive?

PS: “A little bit, I think. This car wants to run differently to a current car. The rear wants to run a lot lower so you’d need then to run it a bit stiffer. The tyres are a bit stiffer vertically too, so maybe you put a bit more into the suspension. Not massively different, just a little. I was worried about how the 18-inch tyres would be be on the kerbs but drivers are commenting that they are very good there.”

Will the thinner sidewalls of the tyres have less aerodynamic effect as they bend than the previous big sidewall tyres?

PS: “Our main objective was trying to have cars which followed each other, but I also wanted to close the grid up. Having spent many years designing cars, I know it’s difficult to handle the deformed tyre shape, around the rear wheels particularly. It’s very difficult to simulate in CFD and tunnel. What do you simulate to? We all use a nice steady-state fast-corner tyre shape, but it’s not really like that; it’s all over the place. Because that’s so difficult the top teams with the big aero departments do a much better job on that than the little teams. So I tried to make that less important – and so we moved the bodywork away a little bit from the tyre, not a huge amount. Then made the lateral stiffness of the tyres greater so they didn’t move around quite so much.”

Does the current stipulated weight distribution range carry over?

PS: “We moved it back 0.5%. I wanted to move it further than that for the reasons I stated before, that you match the weight distribution to the aero distribution and I wanted to move the wake further back. But the teams pushed against it, saying it was going to be too difficult to package within the restricted wheelbase. It’s not perfect. I have three aerodynamicists and I’m pitting them against a few thousands but I’m sure it’s going to be measurably better than what we’ve had.”