The 2022 chassis regulations allow for very different design philosophies to be used, and teams across the grid have chosen their own paths to follow. The AT03 is relatively conventional and conservative in both its design and layout. The side impact structure supports the leading edge of a rectangular heat exchanger intake on either side of the driver cell. The cooler housing lays very flat, with the upper surface sweeping downwards towards the car’s rear. The underside of the cooler housing is heavily sculpted away for aerodynamic benefit. However, with so much scope for different design concepts, AlphaTauri has built some flexibility into its concept to give it scope for change if the team discovers a better one later down the line.
‘We have reasonable fluidity in our design,’ confirms AlphaTauri’s technical director, Jody Egginton. ‘It’s been this approach for several years now in this team but, with a new regulation set, we are all starting from the same new point. We focussed very much on making sure what’s under the skin gives lots of scope for us to develop the aerodynamics of the car without having to make expensive and non-performing architectural changes.
‘We’d hate to be cornered by an architectural bit of hardware under the skin that we probably could have dealt with, so we believe we’ve built in as much scope as we can to make quite reasonable changes in something like sidepod geometry, or engine cover, without having to do new radiator packages etc.
‘It’s the same story with the front wing / nose interface. I’d imagine many teams are working on that simply because of the newness of the regulations, but the way we’ve done that will not limit us if we want to change it. However, I’m sure there are concepts out there we couldn’t adopt. For example, we’re running pushrod front suspension. If we decided to go to a pull rod layout, that’s unlikely to be happening in season.
‘As we get more familiar with the regulations in later years, we will probably get a better read on where we need to focus. For now, we want to develop quickly without having to do a lot of extra work to get the aerodynamic surfaces you want onto the car.’
Because the regulations have been formulated over a large period, the changes to the safety-related regulations added mass and structure to the chassis. An unexpected factor has been the need to beef up the ground effect floors, which proved more vulnerable to damage and flexing in early 2022 than expected. On top of that, geometrically, the regulations have changed regarding the minimum sizes of some chassis elements. Consequently, the cars are physically larger.
‘The mass of our chassis is reasonably close to what we predicted,’ notes Egginton. ‘On top of that, you’ve got the new wheel and tyre package that has picked up a lot of mass. Again, that’s known, but then some of the other things like the brakes are larger, and the brake ducts are therefore larger to go around them. So essentially, you’ve just got more material in play there.
‘Other things like the wishbones are heavier because they are a structural part, and they’re shrouded in the aero element. And when you put a shroud on something, you need a bracket. In the past, the structural section of the wishbones would also have been the aerodynamic section. None of this is a surprise, but it’s tough to do an underweight car. I can’t understate that. And I think within a new regulation set, you’re forced to learn some new tricks, understand the rules and see where you can optimise the weight.
‘Year one, you just want to get your car out. You want to get through homologation, and you want to start learning. How lightweight can we make it? How long are the bits going to last?. This floor is very different though. It’s contacting the racetrack a lot more than the old regulations. The last thing you want is to be leaving large pieces of the floor on the track because you’ve tried to take it too far. On top of that, there’s the budget cap. You’ve got to be spending your money wisely, and that’s another balancing act. It is challenging.’
AlphaTauri bought the gearbox and rear suspension parts for the AT03 from Red Bull Racing. Before 2022, however, AlphaTauri would run the previous year’s components from Red Bull so, in 2021, it used the 2020 Red Bull parts, in 2020 it used the 2019 parts and so on. This saved on resources, and meant AlphaTauri had access to a lot of information on the parts, and a year to understand them, before they were implemented on track. However, in 2022, because of the extreme changes in car design, the team had no choice but to wait for Red Bull to finish the design and optimisation of the gearbox and rear suspension on its car before it had a chance to see the final design.
‘We’re using identical parts to Red Bull in the case of the gearbox, the hydraulics and rear suspension,’ notes Egginton. ‘When you’re taking current year parts, they’re evolving the design, and we’re in the loop with what’s going on as the design is evolving. It means things come through later, and the changes have more impact on what we’re doing, whereas when you take one-year-old designs, you know what you’re getting, it’s fixed. You just take the parts and put them in the wind tunnel. That’s it. You might fiddle with shrouds and other bits and bobs, but it is what it is.
‘This time we’ve been evolving quite rapidly as Red Bull evolve and, the way the regulations are now, the aerodynamic surfaces are owned by ourselves anyway. It’s been an extra challenge, and I think we’ve navigated it quite well. We have good support from Red Bull, and its extra overhead for them as well. There’s a good chance of us going back to the year-minus-one specification for these parts for next year. The beauty of it is that we can look at what is available each year and mix and match. This is the fourth year of the partnership with Red Bull taking their parts, and we haven’t done the same thing any two years. It’s been an extra variable this year, but we’ve managed it well, and the designers in the aero department have done a good job of making sure we’re up to speed as much as we can be. So, we’ll see what we can buy, and what we want to develop going forward, and we’ll keep evolving.’
AlphaTauri is one of just two teams with a similar suspension choice at the front and rear, utilising pushrod suspension all around. Freezing the front suspension architecture is a decision teams make, in relative terms, earlier in the programme than a lot of other decisions. Egginton explains: ‘Front suspension was decided before we did floor development, or even the car concept was finished. We looked at pushrod and pull rod options. We were mixing and matching that with floor directions, front wing directions etc.
‘But at the point in time when we had to make the call, the pushrod was the most performant for us at the front. So, based on our numbers, that’s the direction we went, and then we developed around it because you can’t wait forever. If we visited it any later, we would have compromised the chassis. The pull rod design has benefits in managing some of the flow structures, but from where we were with the car at that time, the pushrod was the best solution. It will go into evaluation again as we start looking more deeply into what we want to do next year, and it will come back on the table again with a lot of other developments.’
The rear of the car was different. As the customer, when Red Bull made their decision on what they wanted to do mechanically with the suspension, that was what Alpha Tauri were given and they’ve developed our car aerodynamically around that layout. ‘It functions as we want,’ says Egginton. ‘We’ve got the stiffnesses we want and the range of adjustment. I don’t feel that Red Bull dropped its concepts on us last minute. It’s something we’ve been fully in control of and working around. There’s a range of approaches to suspension design, and the key point is it matches your car concept. I’d have hated to have been given something we couldn’t make work because then we’d have a car that’s not performing. So overall, it is what it is, and we’ve developed the car around it well.’
With a ground-effect floor, getting the most aerodynamic load means running the floor as close to the ground as possible. But the closer you get to the ground, the higher the risk of inducing instability. Floor stiffness can affect behaviour, or lead to an oscillation, which means you’re picking up the load and then losing it. Ultimately, that’s upsetting to the car’s performance as the aero load on the tyre contact patch varies. Load means performance, which translates to better lap times, so teams will fight for peak load and, logically, all try to exploit that.
‘We had an awareness of potential porpoising in the development process, but it’s hard to correlate to the full-scale car. It wasn’t until the car was physically running that we could get a good read on it and, like anything else, try to correlate it to our model. As part of the development process, we want to maximise the operating window and minimise the points where this oscillation starts to become a problem. We keep an eye on not upsetting the platforms to the point that we start being overly compromised. There are nuances with the car’s behaviour that don’t easily correlate. So, when porpoising occurred on track, there were some differences between what our simulator showed and how the car reacted on track. We didn’t go into great detail to model that in the simulator because we wanted to avoid it.
‘We certainly know where we want to go to get maximum aero performance, and what we’ve got to do, and how to do it in a way that the driver can handle it without making the car too difficult to drive. We’ll find aerodynamic solutions to de-sensitise the floor with minimum load loss. At the end of the day, we want to maximise the load over the biggest possible window. The aerodynamicists in every team will be looking to get as much as they can, while minimising the risk of the floor stalling. It’s just a trade-off between ultimate load and giving the driver a car to operate over a large window. We’re exploring everything now and just scratching the surface, so we’ll probably have to take the car to an uncomfortable place to learn more about it.’
