Mark Hughes: How Mexico’s quirks changed F1’s lead fight – The Race

Mexico City’s extreme altitude always tends to contribute to some interesting performance dynamics between the cars. When the air is 25% less dense than at sea level, the difference between a Formula 1 that drags normally and one that does not is much less than usual. For the same reason, the reduction in downforce means that every additional increment produced is extremely valuable.

That largely explains why the high downforce but trailing Mercedes – a car that was almost 0.6 seconds off the pace in Austin last week – was in full swing here and only a best last lap from Max Verstappen secured the Red Bull Pole from the Mercedes of George Russell. Here it was Ferrari who was nowhere, fifth and seventh and 0.6 seconds off the pace.

For reasons largely unrelated to aerodynamics, altitude is also the reason the Ferrari isn’t at its best here, as Carlos Sainz suggests: “We lose a lot of performance at high altitudes,” he said. he stated, “but I think it’s a unique one.” The altitude of this engine is not exactly as we would like. We knew before coming here that we were going to have to make compromises.

It refers to the Ferrari’s unique intake and turbo configuration. With super long intake tracts (which increase turbulence and flammability of the intake charge), a lower revving MGU-H and a smaller turbo (which requires less electrical power than others to rev quickly), it usually has a significant acceleration advantage out of corners, albeit at the expense of earlier clipping at the end of the straights. With the 25% reduction in air density in Mexico, this advantage disappears. A bigger turbo is ideally needed.

The power delivery to the front of the Ferrari (at normal altitudes) is even part of its low-speed cornering handling assets. Take a look at any Charles Leclerc telemetry from this year and you can see just how much he straddles the throttle and brakes in the slower corners, using it to boost the turbo. It’s an incredibly complex style and one that Sainz has been able to emulate throughout the season. This has implications for the car’s layout, requiring a strong front end.

So there are the basic traits of the top three cars – and how their strengths and weaknesses are modified by Mexico City’s unique challenges. The Red Bull is a great all-around combination of low drag, good power and consistent downforce at all ride heights. The Mercedes is traily but has very good downforce if it can be low enough – but tricky low-speed handling due to the compromise made necessary by its rear suspension to combine low- and high-speed cornering performance. The Ferrari has great downforce, sits somewhere between Red Bull and Mercedes in drag, and generally has a low-speed acceleration advantage. But not here.

Now consider the particular circumstances of the day. Teams were uncharacteristically reliant on FP3 due to Friday’s 2023 Pirelli test in FP2. The track temperature this morning was around 39°C. But all it takes is a bit of sunshine to raise the temperature of the track at this altitude and at the start of qualifying, it was up to 50°C. As Russell pointed out, this not only reduces overall grip, “it also changes the limitation from the front to the rear of the car.”

In FP3, Red Bull were struggling for a front-end and Mercedes were in a very happy place, with Russell and Hamilton leading the times 0.4s ahead of Verstappen and 0.7s behind the Ferraris. But around a hotter 11C track, the trim limit switches rearward as the rear compound overheats quickly. It was perfect to bring Red Bull to its sweet spot, less good for Mercedes and even worse for the already oversteered Ferrari.

But even then the Mercedes was still fully competitive with the Red Bull, essentially faster on the corners, slower on the straights and about equal on the lap. Sergio Perez and Hamilton both suffered from power unit derating issues (another hazard from this altitude) and with Ferraris struggling, so the battle for pole distilled down to Verstappen vs. Russell, especially after Hamilton had his first Q3 scrapped for track limits.

“Arrgh,” Russell yelled in frustration after his final trick slipped away. “Pole was there for the taking.” He settled for his first race time, which was 0.304s slower than Verstappen’s final flyer.

Fresh out of the car, Russell was convinced he had lost the lap with a moment of oversteer between Turns 4 and 5 and that his last moment racing through the curbs as he entered the stadium was simply to trying to make up for lost time. in the previous incident. But a look at the GPS of each lap shows that the quick oversteer cost it almost nothing and that during the first part of the Esses (turns 7-8-9) Mercedes’ greater downforce had brought back Russell ahead, with the Red Bull’s greater straight-line speed then bringing Verstappen level as he approached the stadium section. There was nothing between them as Russell then picked up too much speed in Turn 10 and crossed the exit curb.

It might well have been Verstappen’s pole even if not for Russell’s mistake, as Red Bull had always been fastest in the final sector. But Russell was not mistaken in believing that the pole had been possible.

In the end, the best all-around combination of car and driving characteristics secured Verstappen the pole.