Let’s start from the beginning. This year’s new regulations for the design of F1 cars have made a big leap: The aerodynamic lift is no longer generated by the vast majority of wings and other aerodynamic components on the body surface, but by the ground.

This transition introduced a problem that no team anticipated when designing the car or – in the winter – simulating its aerodynamic performance. The phenomenon of jumping in straight lines, called porpoising in English.

In short, as the car’s speed increases and it is pushed towards the ground (by the increasing vertical force of the air), the gap between the ground and the tarmac at the rear of the car for air to escape decreases.pass.

As the car continues to accelerate and the car sinks downwards, this gap essentially closes and the air can hardly get through. That’s why we’re seeing so many sparks fly from the car lines this year, in straight lines and fast corners.

So when the slit closes and the floor rests on the tarmac, the airflow passing under the floor of the car drips. This pushes the bottom up, opens up again in the slot in the rear of the car, again starts creating the very strong lift that pushes the car down, and so on.

The problem of bouncing (porpoise) has been observed in every car since the first Barcelona winter tests, no matter how different the design philosophy. It is observed from Ferrari with the very large side air intakes to the Alpine with a wide body end to the Mercedes with air intakes and body end that are too thin. The latter is compared by F1 designers to the shape of a glass soft drink bottle on the top.

How jumps negatively affect different cars

But there is one big difference: the problem of jumps is just as big for the Ferrari F1-75, which currently dominates Formula 1, as it is for the Mercedes W13, which still has countless problems that prevent it from increasing its speed to the surface bring . . . Why didn’t Ferrari, like Alpine, pay as much as Mercedes?

After many different solutions tried by the teams (adding flaps to the floor, holes in the floor, increasing the height from the floor, suspension changes, etc.), the answer has to do with the construction and specifically with rigidity. the bottom of cars.

It seems that Ferrari and Alpine have a much stiffer bottom than Mercedes, but so does Red Bull Racing – who were forced to fit large stiffeners to the bottom of the RB16, creating a new big problem that is now being attempted for the second time to solve : increase weight by about 7 pounds. Perhaps the large side vents on the Ferrari F1-75 and Alpine A522 contribute to the stiffness of the floor compared to the small and tiny on the RBR and Mercedes respectively.

Veteran Alpine Technical Director Pat Fry explains that the width of the tail of the A522 played a key role in the team’s success in tackling the porpoise: “If you see [το πρόβλημα] In some other cars it was terrible. Those who have opted for a very narrow back cannot have excessively protruding outer parts of the bottom. Therefore, you need to make the bottom more solid, and therefore add pounds. “We have quite a wide end of the body and that makes it easier for us.”

The Brit also said that Alpine’s main goal was to have a much stiffer floor than even the FIA’s elasticity tests required: “For his elasticity tests FIA which, if I’m not mistaken, is 20 [χιλιοστά ελαστικότητας] For a given load, our floor was ten times stiffer than needed! “The resiliency of the floors for aerodynamic benefits was the trap many of the other teams fell into.”

Fry concluded by saying that porpoises “is clearly an aerodynamic issue. I think the jumps and especially their intensity surprised everyone. We certainly didn’t predict it with a model or in the simulator, but I think that last but not least, the way we designed our car made us less prone to the problem than others.

His words confirm what Alpine achieved quite unexpectedly in Bahrain winter testing: being the only one able to flip jumps on and off with ease when they try. Then, in early March, competition director Alan Permain said: “The jumps we are talking about and the porpoise, We can turn it on and off. We know what causes it and what stops it.”

What is the difference Ferrari Mercedes

Based on the barely visible and intense jumps of the Ferrari F1-75 in Australia, the question remains: Why is porpoising disastrous for Mercedes and not Ferrari?

The Scuderia have not made a clear statement publicly. For example, it didn’t specify whether its bottom is stiffer, whether the further stiffness is due to the Cavallino’s very large side vents, or anything like that. What is certain, however, as Mercedes Toto Wolf puts it, is that the Ferrari F1-75 only presents the problem on straights and does not drag it along in fast corners either – as does the Mercedes W13.

“Our jumps have a worse effect because we carry them in the corners at high speed and we see where we lose speed.”said Toto Wolf. In Australia we lost almost a second in three or four laps from 9 to 12. Can this be miraculously resolved? Definitely no. “I’m optimistic that we’ll finally make it.”

This is disastrous for the ‘Silver Arrows’ of Lewis Hamilton and George Russell and it was seen in the third part of the Melbourne circuit. In four laps, the fast 9-12, the W13 lost 0.49” – almost half a second. In the first two parts of the track it was about 2 tenths slower than the Ferrari at slower speeds.

The problem of W13 instability in fast corners caused by jumps was described by George Russell: “I tried many different things to get to the limit with jumps and then I always lost a lot of time in very fast corners. There we lose all our time in the round. I don’t have the confidence to attack with the bounces. “If the car is being bounced up and down, you can’t just throw it into a very fast corner.”

In contrast, the winner of two of F1’s first three GPs this year, Charles Leclerc, despite visibly struggling with straight jumps in the F1-75 cockpit, sounds much more comfortable: “Of course I can feel it. But I don’t know why, but we’re not that sensitive to it. In terms of performance, it doesn’t bother me that much.

I couldn’t have moved faster [στις κατατακτήριες δοκιμές της Μελβούρνης] if we didn’t have the bounces. We definitely have to deal with that because it doesn’t contribute to the stability of our performance. If you have bounces on the turn, that can be a problem.”, concluded Monegasque. Of course, his last sentence does not express that there is a corresponding problem for the Scuderia.

Ferrari tested a modified floor for porpoises at the free trials in Australia but did not compete in Melbourne – and will not use it at Imola at Easter. Red Bull solved the jumps by reinforcing the bottom, but in doing so catastrophically increased the RB16’s weight in its effort. Mercedes tries in other ways – for example, he tries to increase the height of the floor from the ground.

Mercedes has chosen not to sacrifice the W13’s original philosophy of aerodynamic performance to solve porpoises and believes – still – it can deal with it in other ways. Wolf himself said he could do it in two races, in three races, in the summer or at the end of the year. For Ferrari it’s not even a serious problem.