Ferrari forced to sacrifice aerodynamic downforce amid alleged technical violation of SF-24 floor. What's behind the new FIA Technical Directive that affects Ferrari.

After the mini-DRS, concerns about the T-Tray control system, and speculations about water-cooled tires, a new technical dispute ignites the Las Vegas Grand Prix weekend. According to a report first published by the German outlet Auto Motor und Sport, the Federation has taken immediate action to prevent potential illicit practices related to controlling floor wear. The FIA aims to eliminate any doubts about the grey areas in the regulations, building on what was done in 2022 with Technical Directive 039.

Ground-effect technical regulations have encouraged teams to lower their ride height as much as possible. The three-dimensional floors equipped with Venturi channels generate more aerodynamic downforce the closer they work to the ground. Over the years, this has prompted teams to come up with strategies to reduce floor wear in order to lower the cars even further. The cars now touch the ground much more, and due to their design in the plank area, its flexibility has become more important than in the past, as confirmed by FIA Technical Director Nikolas Tombazis back in 2022. Previously, it was just something that could gain a couple of millimeters of height, whereas now it can significantly affect the car’s behavior and the driver’s perception.

The technical regulations stipulate that the plank, the resin board running along the underside of the car, must have a thickness of 10 mm. It cannot wear more than 1 mm over the course of a Grand Prix, or the car risks disqualification, with measurements to be taken at the designated holes. However, at the start of 2022, the FIA suspected that some teams were exploiting excessive flexibility in the plank to reduce its wear when in contact with the track surface.

For this reason, starting with the 2022 Belgian Grand Prix, the FIA extended the inspection to the area around the measurement holes with Technical Directive 039, checking that the plank did not have discontinuous rigidity and was instead made from a material of homogeneous density, as required by the regulations. It was also specified that no tricks would be allowed to protect the edges of the measurement holes from wear. However, two years later, it appears that the directive has not completely closed all the grey areas.

The 1 mm wear limit actually does not only apply to the resin board but also to the entire plank assembly. This includes the metal plates, known as skids, which are typically placed in alignment with the measurement holes for the thickness. According to Auto Motor und Sport, the FIA is concerned that some teams may be using elements or protective treatments to limit wear.

However, the technical regulations leave little room for interpretation. Article 3.5.9 states that the skids must be made exclusively from titanium alloys, specifically AMS4928 and AMS4911. It further specifies that the plates “can only be milled from solid material and no treatments can be carried out before or after the machining process, such as forging, rolling, welding, or surface treatments.” The same article clarifies that the skids “must be mounted so that their entire lower surface is visible from underneath,” thus prohibiting the application of additional protective plates.

Recent reports also suggest possible tricks related to the mounting and deformability of the fastening screws. Again, the regulations are very clear, specifying that the screws “must be no smaller than an M6 and must be made from steel of grade 12.9 and 10.9.” In theory, the screws should not protrude from beneath the plank assembly, and thus could not serve as protection against wear. The thickness of the plank varies between 10 and 9 mm, and it is mounted on the reference plane, from which the screws cannot extend more than 8 mm.

The latest intervention from the Federation is surprising due to its timing, given the minimal notice given to the teams just hours before they take to the track in Las Vegas. According to our information, some teams are puzzled, as typically a technical directive requires time to be implemented, since it adds to the technical regulations during the season and therefore should give teams adequate time to adjust. The approach used by the FIA does not seem to be a formal technical directive but rather a targeted communication to the affected teams to clear up any doubts about the interpretation of the existing rules.

This all comes with just a few days ahead of a Grand Prix that will be particularly demanding in terms of floor wear. On the straights of Las Vegas, cars spend a lot of time over 300 km/h, when aerodynamic load is at its maximum, pushing the cars down onto the track. Some teams, with Ferrari suspected among them, may need to raise their cars and sacrifice some aerodynamic downforce, but only the track will reveal the impact on lap times.

— see video above —