In a year when so many Formula 1 teams have hit different upgrade problems, there is one common theme among them: car balance headaches.
From Max Verstappen complaining his RB20 has turned into a ‘monster’, to Ferrari’s return of high-speed bouncing, to the Mercedes becoming nervous in qualifying and Aston Martin losing its way for a bit.
Each team has experienced a near identical scenario of delivering a car upgrade that brings with it extra downforce but with it the side-effect of an altered car handling to make it feel worse from the cockpit.
That so many teams have been struck down by this is no coincidence, because the extra performance being added this year has exposed some inherent technical challenges with the current ground effect cars.
And central to it all is the way that two performance factors dominate handling. This is the varying downforce levels produced at different speeds as the car is pushed the car closer to the ground, allied to how the tyre temperatures are impacted throughout the lap.
Both of these elements are dynamic and are forcing teams to chase the least worst compromise, rather than seek a perfect solution.
This is something that has been known for a while, with Mercedes technical director James Allison opening up at the end of last year about the problems teams were having to wrestle in getting the current cars to produce the downforce when it was needed the most.
“There's a sort of fundamental difficulty in these rules which is that the car will generate more and more downforce the lower it goes,” he said.
“That’s not without limit, because you don't want it to just magnet itself onto the ground at the end of the straight, because at the end of the straight you generally are not going around the corner.
“If that's where your best downforce is, it's just generating drag for you. So in order to cope with the load that that creates at the end of the straight, you're going to have to have stiff springs or higher ride heights.
“If you've got higher ride heights, then that means that you're not going to be where the downforce is. So that means stiff springs. And so with these cars, there is this sort of treasure of downforce to be had near the ground, and you can find lots of it there. But you also have to survive the end of the straight.
“So there is a sort of a little bit of a limit that this end of straight downforce consumes ride height that then punishes you in the low speed. And there comes a point where you can't support the end of straight loads without hurting yourself in the slow speed so much that it's no longer faster to have that end of straight downforce.
“Everyone is trying to get things so that at the end of the straight you don't have quite as much load, but right next door to it you have loads, because the fast corners are right next door to the end of the straight.
“Then you also want to hang on to an adequate amount for the slow speed stuff, despite the fact that the car just wants to lose all its downforce as it raises off the ground.
“That's the challenge. I'm not saying anything that every person this pit lane isn't wrestling.”
The downforce transition
Teams seems to be struggling more with these compromises this year though. Aston Martin’s engineering director Luca Furbatto suggests that what is happening to the cars right now is quite simple to explain, but incredibly complex to get on top of.
Speaking about the balance issues that have become a hot topic in F1, Furbatto said: “It is a problem of ours, but listening to the team radios I have the feeling that it is a fairly general thing.
“There is the difficulty of these cars in turning in the corner entry phase. Let's say that the aerodynamic platform helps to find the load on the rear, to the detriment of the front, during the various phases of the turn.
“Therefore, you can go from a neutral car on entry that becomes understeering before the apex and then becomes very oversteering on exit. This transition, which in the past was never so extreme, is becoming increasingly clear because these cars are reaching very high load [downforce] values."
Furbatto suggests that teams have added around 45 percent more downforce since the ground effect cars were first introduced at the start of 2022.
This has meant that teams are also finding themselves constantly walking a tightrope of trying to bring more performance without falling off it and opening up a world of porpoising problems.
“If you reduce the bouncing a bit because you get the airflow under the car right, then it becomes natural to try to bring an update that increases the load a bit, and the porpoising returns," he said.
“The more you push this regulation, the more there is the risk of seeing bouncing. It will be a phenomenon that we will have to deal with until the end of 2025, and I think it is one of the reasons why we will take another path in 2026.
“After all, the drivers, even if they do not say it publicly, complain about the porpoising and several complain of back pain. I think this is an element of the regulation that needs to be addressed”.
But to get a perfect lap means not only addressing the downforce issue, because equally critical is how the tyres are behaving. And in basic terms, if one axle gets hotter than the other, then that is a recipe for trouble through either too much understeer or too much oversteer.
Furbatto added: “ In addition to having a change in the behaviour of the car when the aerodynamic forces that make the bottom of the car rise and fall, it also matters how the grip of the tyres varies.
“It is no coincidence that in Monza we saw the preparation of the out-lap very different during qualifying.
“You try to bring the tyres to certain temperatures in an attempt to mask those balance problems that in qualifying can be more serious than what you see in the race."
The front wing issue
What makes chasing solutions for the common car balance problem so hard is that the areas where car performance can be influenced have changed so much, with the floor now the most important element of all.
Whereas in the past, teams could utilise front wing designs more to help balance the car, now it is not such as valuable a tool.
Furbatto added: “With the previous regulation the load was divided approximately one third to the front wing, one third to the floor and, finally, one third to the rear wing.
“So the wings had more relevance in modifying the balance, compared to today's cars that generate up to 70% of the downforce with the floor.
“The ability to intervene with the front wing to find a balance has effectively halved.”
In fact, the more aggressive use of flexi wings is a consequence of these car balance problems, because teams have realised that one of the best ways to overcome low-speed understeer and high-speed oversteer is to have a wing that exploits aero elasticity.
In varying the wing's characteristics, it can help deliver that extra bite in slow speed and, as it is flexes down in the quickest stuff, that knocks off some of the risks of it putting too much on the nose there.
Without the ability to flex the front wings, teams would face an even tougher time dealing with the car balance problems.
The FIA has been analysing the behaviour of front wings since the Belgian Grand Prix, with a view to seeing if there are any regulation changes needed in this area for 2025.
Furbatto thinks it will be situation unchanged though, because there is no way things can become stricter here if it is not to cause even bigger headaches for teams.
“I don’t think there is an intention to change the 2025 regulation, because the fact that the wing bends within the rules is part of that attempt to find a balance of the cars,” he said.
“I would say that it is a necessary evil of these ground effect single-seaters. Otherwise, with more rigid wings, we would find ourselves with drivers incapable of finding a useful set-up to make the car controllable”.
Ultimately, the experience of this year suggests that F1's current regulations have brought with them some incredibly complex compromises – and that means no end to the balance headaches until the next rules era begins in 2026.
