Tech Analysis: This factor influenced McLaren and Ferrari’s result in China

Ferrari with poor traction since Friday

Since Friday’s FP1, Ferrari didn’t seem comfortable around the Shanghai International Circuit, with both Sainz and Leclerc sliding a lot coming out of the slow corners. The problem persisted in Sprint qualifying when the difficulty in waking the tyres during the out lap forced the drivers to lose a lot of time in the first sector. 

The SF-24 suffering in qualifying and out of the slow speed corners can be explained by many factors. First, the low temperatures in China made it even more difficult for all teams to put brakes and tyres in the right operating window. The new tarmac was very slippery and made even more difficult for the drivers to wake up the tyres. Consequently, both drivers were losing around 0.2 tenths from Verstappen only in the first sector in qualifying. 

Moreover, an explanation for Ferrari’s struggle lies in one of the choices made during the design phase in winter. To improve last year’s SF-23 behaviour in fast corners and to make tyre management an ace up the sleeve for the SF-24, the technical team decided to give up the peak downforce generated by the floor, designing a suspension system able to produce a constant amount of downforce from the Venturi channels at different ride heights, to stabilise the performance on different layouts. This choice limited the porpoising/bouncing effect on the SF-24, making the aero-mechanical platform even more stable throughout the race. 

Consequently, Ferrari lost some of their competitiveness in the slow-speed corners and quickly waking up the tyres in qualifying. The first problem can be solved by adopting different settings for the differential and a different configuration of the stiffness of the rear suspension. This problem could be difficult (but not impossible) for the team to completely resolve during the season. Concerning the second point, a lot will depend on the team’s ability to dive deep into this problem and try to find a solution as soon as possible. Updates will certainly help, but it’s not obvious that this issue will disappear after Imola. 

Seeing the SF-24's behaviour in the sow speed, Ferrari decided to adopt a slightly less loaded rear wing to improve the top speed and facilitate overtaking during the race. This choice turned out to be a double-edged sword: despite having a good top speed, the car was losing even more traction, with Sainz and Leclerc not being able to overtake their opponents on the long 1.2 km straight.

During the race, Ferrari struggled a lot to warm the hard tyres, and when they did, the car didn’t seem as competitive as it had in the previous races, losing ground to Red Bull and McLaren in front. 

Fred Vasseur confirmed they struggled a lot due to the new tarmac and the very little time they had on Friday to understand it: ”[…] we didn't do the job this weekend on this. It's not that the situation is changing massively from one weekend to the next. It can be a bit track-related or tarmac-related this weekend. I think it was very difficult to understand the tarmac, also due to the format, because we did a stint with soft on Friday morning, and then we went to the race with medium, and we didn't put the medium before.”

This weekend was a tricky one for Ferrari, also due to the very little time available to find the right set-up. Despite this aspect, the Maranello-based team will clearly be able to find a solution to their problems, even though another Sprint race format in Miami may not be the best for them. 

Why the MCL38 behaved better than expected

If the tarmac didn’t favour Ferrari, it certainly helped McLaren. The MCL38 is a car that can put a lot of heat into the tyres, wake them up very quickly, and provide a high level of grip to the drivers in almost all conditions. 

This factor was particularly evident in Q3 of the Sprint qualifying because, when the rain came down, causing oils to escape from the asphalt, all cars were sliding, while the MCL38 immediately put the intermediates into their working window, giving Norris the chance to settle on pole on Saturday’s Sprint. 

This ability to wake up the tyres gently but quickly at the same time basically lies in one of the MCL38 project cornerstones: the car has been designed to generate a high level of downforce from the Venturi channels and bodywork of the car, being one of the best in high-speed corners. As a direct consequence, the high level of downforce always available (independently from the circuit layout of the wing set adopted) allows the drivers to put all compounds, especially the hardest ones, into the operating window, with a great advantage in terms of grip. 

This peculiarity, however, only occurs on these circuits, where the slippery tarmac and low temperatures make it difficult to generate heat in the tyres. 

As said for Ferrari, these choices always come with some disadvantages too: the high corner grip is counter balanced by a very poor performance on the straights and especially in slow speed corners. Since Bahrain, the MCL38 suffered a lot (compared to Red Bull) in harpins and chicanes, whistle being at the same level in high-speed corners.

As said by Andrea Stella immediately after the race, this result wasn’t expected, especially in the race distance: “[…] today, I think somehow the track conditions and the cold conditions, the fact that there was no sunshine helped keep the rear tyres under control, and therefore we could use the strength of the car like we saw in qualifying.” These words are proof that the low temperatures certainly gave an advantage to McLaren in managing the hard tyres, which seemed to be working pretty good for them. 

McLaren are now planning to bring some updates for the next round in Miami to improve their weaknesses, to fight with Ferrari on all type of circuits. A lot will depend on how the upgrades will work and if they don’t alterate the balance and behaviour of the car, i.e., if the new parts will improve the weaknesses while still keeping the MCL38 strong points. 

This weekend performance depended a lot on the new tarmac and on the atmospheric conditions faced during the different sessions, but the “rush for the updates” has now started and their impact is going to establish the hierarchies between Ferrari and McLaren until the first races of summer.