The very fact that bodywork cannot be totally rigid means that some flexibility has to be allowed for – and it is this grey area of what that margin is that has been the focus of toing and froing between the competitors and the governing body for years.
What makes the situation even more difficult to police is the fact that the bodywork is designed to flex at high speed, so cannot be physically measured when it is behaving the way that teams want it to.
Static load and push tests can only go so far in identifying such flexion, as the forces imposed on the car when it is in motion will always create more dynamic behaviour.
Teams know this and therefore build margin into the components in order to ensure that they pass the requisite tests in the garage, but still flex appropriately for the aerodynamic effect when they are blasting down straights at 200mph.
Occasionally, however, the teams push the boundaries too far and prompt the FIA to take action in tightening what they believe are acceptable limits for bodywork flexibility.
And that is exactly what has happened right now, with the FIA notifying the teams in a draft technical directive last week that a clampdown is coming for the Singapore Grand Prix.
The TD is based on an original bodywork flexibility advisory that was previously limited to rear wings, but this has now been expanded to include front wings too.
It appears that there are two clear avenues of exploitation going on up and down the grid.
The main concerns, it would seem, that the FIA has when it comes to the rear wing is in the design of the endplates and the mounting pillar(s), with teams now required to submit “assembly drawings or images and cross sections showing the fixation of the rear wing elements to the rear wing endplates, the rear impact structure and the pylon(s)” and “assembly drawings or images and cross sections showing the fixation of the rear wing pylon(s) to the rear impact structure.”
There’s obviously a number of ways in which flexion could be used here, with the main objective for the teams being to reduce drag. This has the double benefit of allowing a higher downforce arrangement to be used also, in order that the gain can be levelled out at either end of the spectrum.
Historically F1 teams have achieved this drag reduction through two main methods; closure of the gaps between elements and longitudinal rotation of the entire assembly.
The introduction of slot gap separators on the rear wing in the mid-2000s largely prohibited the first of these, although the governing body was still keeping a keen eye on how the wings are designed in order to prevent teams from taking advantage of this.
The second is always a little more tricky to police, especially from a dynamic point of view, and is why the FIA requested that teams add reference dots onto their rear wing elements from the Azerbaijan Grand Prix in 2021.
These dots can then be monitored via the rear facing camera and provide insight into how much the wing tilts rearwards under load.
It’s unclear, at this stage, if this is how the FIA has discovered the questionable use of flexion in the rear wing of some competitors, or whether it feels that it is best to close off some potential development paths that teams could have pursued soon.
One interesting avenue of rear wing development emerged recently, with Alpine and Aston Martin simultaneously introducing similar solutions at the Monaco Grand Prix that others have now followed.
While their designs fall under the same category, owing to the way the tip section connects to the endplate rather than having a smooth surface transition, they do so in a slightly different way.
The position and orientation of the metal bracket is the difference here, with Mercedes and Ferrari going out on the same limb as Aston Martin, while AlphaTauri and McLaren have followed Alpine’s example.
In both cases, the solution is attempting to alter the efficiency level of the wing, as the teams conjure up ways to alter the tip vortex.
Given the forces applied to these new design concepts are completely different to those modelled ahead of the new regulations being introduced, there could be further consequences, especially if we consider how the slot gap between the elements might be affected.
That is also not to say that similar mechanisms could not be found within the construction of what would be considered a conventional layout, should a team find the right flexion within the layup of those carbon fibre surfaces or any fillets that join sections together.
One area where the FIA has taken an increased interest this year is front wings, with it having emerged that some designs have fallen under the FIA’s gaze already in 2023.
This comes as teams target the front wing as a means to improve the performance of the car in ways that were perhaps not able to be followed in the past.
Interestingly, it appears their focus this time around is how the front wing is mounted to the nose, as the FIA has instructed the teams to upload further design information in this specific area.
This has become a topic because this is effectively new design architecture, with teams having previously mounted the wing on pylons that connected to the underside of the nose.
This shift has presented the teams with a new sandbox to play with, and it has seen teams push hard in this area to better understand how to garner aerodynamic performance in the area of interaction between the nose and the front wing elements.
The TD also throws more light on how teams might be trying to gain an illegal edge here too, as the FIA says it considers “wing elements that can rotate relative to the bodywork (e.g. nose, endplate or RIS) that they are fixed to (such as rotation about one fixing)” to be outside the rules.
This suggests the way in which the wing elements are mounted to the nose might have more axial freedom than was intended when the regulations were framed.
The latest FIA TD appears to cast a wide net, in order to catch most of the solutions that are currently being fielded, and some that might have appeared in the not too distant future.
However, this won’t be the end of the flexi-wing debate, as undoubtedly teams will continue to poke and prod at what is not explicitly covered in the regulations in order to find yet more performance.
