Gary Anderson on Mercedes’ problems

Gary Anderson, former race car designer and now expert for The Race, speaks about Mercedes’ problems and explains the difficulties the team has failed to overcome for the third year in a row, and that Lewis Hamilton talks about all the time .

In 2024, Formula 1 is still dominated by Red Bull Racing, and Mercedes is still unable to find the key to the specific requirements of the current technical regulations, which are based on the use of ground effect.

It seems that at the Jeddah circuit, with its high-speed corners, the Mercedes team were confronted with a repeat of the same old story that had played out over the past two years.

Lewis Hamilton mainly complained that he had no confidence in the behavior of the rear of the car, and we have all heard that more than once. And he says this despite the team’s assurances, made at the presentation of the W15 chassis, that the main problems identified in previous seasons have already been resolved. But now it appears that the old difficulties persist.

Brackley was able to make some improvements this year, but still did not fully understand all the nuances of the current regulations. Over the past two years I have been arguing that Mercedes engineers and designers need to completely rethink their approach and acknowledge not only that the car they created still has problems, but also the fact that they have not explored the essence of these problems deeply enough. to understand. . Only then is it possible to solve them.

The W15 handles slow corners well, but in fast corners the rear end behavior becomes nervous, making drivers feel unconfident behind the wheel. On the track in Jeddah there are especially many such difficulties, because at high speeds the bottom of the car is pressed even more tightly against the surface of the track.

The faster the car travels, the higher the level of aerodynamic stress, and in Jeddah it reaches colossal values ​​at speeds of almost 340 km/h.

At a speed of 100 km/h, the ground clearance at the front of the car is approximately 25 mm and at the rear 70 mm. As the load increases, the car is pressed against the track, and here you have to rely on the vertical stiffness of the entire structure, which must withstand this.

Engineers know that conventional vertical springs can’t handle this because the suspension will be too stiff and the car won’t handle slow and medium-speed corners well. In fact, the chassis starts to scrape the surface of the track, and of course none of the riders like this.

To cope with such loads, a so-called “central third spring” has been added to the front and rear suspension design. First the side springs are activated and then the central unit comes into operation. In reality, it only takes the load when driving straight, because when the car rolls around corners, this central spring is not compressed.

At low speeds you need to achieve a balance where the front wheels have good grip on the track so that the car responds accurately to steering inputs, especially in the initial stages of corner entry. However, at high speeds you want the balance to be more towards the rear to keep the rear of the chassis as stable as possible. This is exactly what Hamilton has been asking for for more than two years.

This can be achieved in the only way: it is necessary that the center of aerodynamic pressure temporarily shifts as the ground clearance decreases under the influence of growing loads with increasing speed.

The front suspension must have approximately twice the vertical stiffness of the rear suspension to accommodate the redistribution of chassis weight during braking.

And if you can move the center of aerodynamic pressure rearward as ride height changes and speed increases, this is what provides the stability to the rear of the car that racers so desperately need.

Thanks to the stiffness of the central third spring, the rear is pressed a little more against the track – in fact, the front is slightly higher. The amount of change in ground clearance seems small: the difference in ground clearance at the rear of the car at speeds of 100 km/h and 340 km/h is no more than 2.4%. But it is precisely this change that makes it possible to achieve aerodynamic stability in this part of the chassis and allows the driver to fly with more confidence.

As speed increases, the rear chassis is pushed more towards the track, but as downforce increases dramatically there is a risk of the car skidding along the track. And here the design features of the bottom should come into play. As the ride height decreases, you want to somehow control the increase in downforce so that it doesn’t increase with the square of the speed.

To do this it is necessary that the bottom allows the separation of air flows and works on the principle of a “dimmable lamp switch”. You don’t want to lose the pressure completely; you just have to prevent the bottom from contacting the track surface. To achieve this while keeping the center of aerodynamic pressure where it should be is not so easy, but it is a solvable task.

For example, when the bottom comes within 10mm of the track, you want the ground clearance to remain at that level, otherwise you will have problems with the car rolling over. If you try to lower the ride height too much by increasing the vertical stiffness of the chassis, it will only increase sway.

The most important point for Mercedes is this: they must understand the operation of the underbody in detail, in all its nuances.

With the exception of Red Bull Racing, most teams’ cars suffer from a lack of grip and sub-optimal balance in slow or fast corners. But it seems that Mercedes’ problems stem from their inability to find the right compromise needed to make the car perform well in both cases.