Three races in, and the once all-conquering German team has fallen apart. Do not expect a quick fix.
If Formula 1 were to award a word for the year, it would be porpoising, which is responsible for Mercedes-AMG’s eight-year dominance of F1 and its juddering halt.
Anyone who has ever worked with race cars that have powerful underfloor venturi tunnels can recognize the repetitive bouncing motion of an F1 car. Named after the aquatic mammal that skips in and out of water as it travels, the name is echoed by car’s oscillations.
This is due to the car being pulled closer to the ground by the increasing downforce and decreasing speed. The floor hitting the track surface or airflow separation at high speed causes the underfloor aero to stall. You can also cause it to stall by hitting bumps. The car rises as the downforce is temporarily reduced. After that, it is sucked back down as the underfloor functions as intended. This cycle continues, resulting in the bouncing motion.
Porpoising is a problem in all F1 cars, regardless of their age. Porpoising on the straights is not necessarily a problem as long as it’s well controlled and not too savage to cause damage to the driver or car. It is a matter of how fast the porpoising stops once you reach a corner, and what compromises are made to control it.
Aerodynamics dominates the performance of cars at corner entry. This is doubly true for one with a dynamic car. You need a stable, compliant mechanical platform as well as an aero-balance shift at the turn that is both reliable and controllable. Unpredictability is a hallmark of a bouncing car.
Sir Lewis Hamilton, seven-time champion, stated that you can’t stop it. “The only thing you can do is take off the gas pedal and drive slower.” “But when it’s moving up and down, it’s also bouncing. If you turn in at 200 mph, the car is loaded and unloaded it can become quite unstable.”
Hamilton was referring to the behavior of Hamilton’s car in high-speed left/right turns nine and ten in Australia. This followed the long, flat-out blast that was where porpoising was most evident.
Although the Ferrari was more aggressive than the Mercedes in porpoising, Charles Leclerc was still able to win pole position. This is because Ferrari had to make much less set-up sacrifices, and although it was still felt in turn nine, it had a smaller effect. Mercedes drivers, on the other hand, have to be less aggressive in fast corners to allow the car to settle at least partially.
Mercedes must make greater compromises in its ride height set-up. Because Mercedes’ porpoising problem is more severe than that of Ferrari, this means less downforce and lap time. This also means that there is more drag. It’s also why Bahrain was the best circuit this season. The corners were largely lower speed, which allowed Mercedes to run slightly lower than in Australia or Saudi Arabia.
Why is porpoising so hard to stop? It isn’t difficult, but it can cost performance. The problem is that you can increase the ride height to reduce porpoising. This decreases the aerodynamic seal and thus the overall downforce of your car. It also effectively’vents’ low pressure, especially at the point where it grows rapidly as the ground gets closer to the car. Downforce is performance. The grip it generates is far greater than what is possible mechanically.
Simulating porpoising can be difficult because the car cannot go too low to the windtunnel’s rolling belt or it will damage itself. CFD, however effective, is complicated and can break down when simulating objects close to the ground. Mercedes has been able to build better models using the data it has collected, but only by driving the car can it fully explore the problem and possible solutions.
F1’s cost limit, which is $140 million (PS107m in 2022), and the absence of testing mean Mercedes doesn’t have the money for endless trial-and error fixes or the track time.
A combination of modifications to the aero, including floor design and floor structure, is likely the solution. Because floor flexing can lead to more problems. F1’s new regulations also simplify suspension systems by eliminating hydraulic assistance and inerters that would have made it easier to control porpoising.
It will take time to fix it. Team principal Toto Wolff reiterated his mantra of “no magic bullet” at all opportunities, while driver George Russell stressed that only incremental changes to the car will be made in the immediate future.
Mercedes may be managing expectations and has a solution near its doorstep, but it has become less optimistic about solving its problems over time. It’s likely that Mercedes will need to work hard to fix its problems, even though its main rivals believe otherwise.
Even though F1 is just entering its fourth race at Imola this weekend it’s hard to imagine Mercedes becoming a championship threat, even though it has been the clear third-best of all 10 teams in each grand prix.
It is possible that it will be a front-running force once again in the second half of the season. It might be fighting for wins that save face and making a nuisance out of itself in a Ferrari versus Red Bull title fight.