McLaren’s ‘mini-DRS’ uncovered: The latest chapter in the great ‘flexi-wing’ debate

McLaren and their ‘flexi wing’ design are once again making headlines following the race in Azerbaijan’s capital.

But this time, it’s their rear wing that has sparked debate, raising numerous questions about the design, function and legality of it. But did this really give them a significant advantage in their victory, and if so, just how much?

A brief recap on the F1 2024 flexi-wing debate

Earlier this season, McLaren ’s front wing on the MCL38 became a hot topic, appearing more flexible than those of other teams.

Of course, no aerodynamic element on a Formula 1 car can be perfectly rigid – these components are subjected to immense forces, and some level of deformation is expected. The real question is where the line is drawn, a decision is made and how it is regulated by the FIA. In the case of front wings, the FIA conducts static tests, measuring how much the flaps deform under certain loads. So far this season, the FIA hasn’t declared any front wing design illegal.

But this isn’t the first time we’ve heard debates over flexi wings. Engineers are always seeking loopholes in the regulations to give their cars an advantage on track. A well-designed flexi front wing can offer a substantial benefit.

Its main role is to generate downforce for greater stability through corners, but downforce becomes less essential on straights, where top speed is key. Flexi front wings reduce their surface area at high speeds, thus lowering drag and allowing for better straight-line speeds. Essentially, you get a sort of active aerodynamics that adapts to the track’s demands.

Interestingly, McLaren’s performance surged following their significant upgrade package in Miami, which included a redesigned front wing. But they’re not the only ones. Mercedes also entered the flexi wing conversation, transforming their car’s performance with a new front wing introduced in Monaco. However, Formula 1 is far more complex than this, and it’s hard to believe that a front wing alone could make such a dramatic difference.

Despite enquiries lodged by rival teams against McLaren and Mercedes, the FIA has not deemed any of the designs illegal.

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So, what’s the deal with the rear wings now?

While flexi front wings have been a recurring topic in Formula 1 history, what we witnessed in Azerbaijan was something entirely different.

This time, it was McLaren’s rear wing that attracted attention, deforming more than usual on the start-finish straight. The leading edge of the upper plane of the rear wing seemed to lift at the tips, creating a greater gap between it and the main plane. This effectively created a “mini DRS” system, which activates under load and reduces the rear wing’s drag, allowing for higher top speeds.

The key question is: how much difference can such a seemingly minor deformation of the upper plane make? On Sunday, we saw Leclerc struggle to catch Piastri down the start-finish straight, even with DRS open and a slipstream.

If we examine the top speeds during qualifying, McLaren was, unsurprisingly, among the slowest on the grid in this regard, as they have been in many previous races. However, with DRS open during qualifying, we need to look at the speeds with the system closed.

This is where things get interesting: McLaren actually topped the charts with a maximum speed of 320 km/h, compared to Red Bull’s 317 km/h and Ferrari’s 319 km/h. However, the differences are marginal.

The subjective feeling is that the advantage McLaren gains from their ‘mini DRS’ system is minuscule, barely noticeable on track. To make a significant impact, they’d need to reduce the wing’s surface area—or its geometry—far more than the deformation we saw on Sunday suggests.

Ultimately, it’s up to the FIA to investigate and determine whether this design is legal and, based on current evidence, there is no reason to believe that it isn’t.

As it stands, McLaren’s engineers should be commended for finding a clever and, more importantly, legal way to give their drivers an edge – however slight it may be.

Potentially even more interesting now is how other teams respond. Do they launch further enquiries with the FIA or follow in McLaren’s footsteps with their own design? Maybe both…

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