We’ve already seen a lot of focus on the Mercedes rippled floor, and the McLaren diffuser strake solution, but now attention has shifted to something unique that Ferrari has done.
The solution that’s run on the SF21 throughout the test plays into the team’s attempts to mitigate the losses forced on it by the 2021 regulation changes which result in more turbulence from the rear tyre finding its way into and over the diffuser if not adequately dealt with.
It’s an issue that’s been attacked from a different angle by every single team, especially when it comes to the aerodynamic devices that line the outer edge of the floor that’s been cut away at an angle.
However, whilst Ferrari has an intricate arrangement on the edge of the floor itself, it has installed a solution that’s altogether more interesting on the side of the diffuser.
As can be seen in the photo above, here we find a trio of fins that have been directly incorporated into the diffuser area.
These will undoubtedly be aimed at preventing the turbulent airflow being pushed off the sidewall of the rear tyre from causing a nuisance to the airflow passing over the floor.
This is an incredibly important detail when we consider that the FIA’s new regulations have trimmed the brake duct winglets, usually found in the lower half of the assembly, by 40mm for 2021. It was these that previously played a similar role in tidying up that flow instability.
Ferrari adding the fins on the edge of the bulge created in the floor to facilitate the upsweep of the diffuser beneath may also go some way to protecting the flow into the coke bottle region beyond.
This flow structure has always been important but has even more significance now the teams have lost some of the floor ahead of it.
This is one of the reasons that Ferrari has spent its two development tokens on the gearbox carrier and made changes to raise its suspension layout, as it clears space above the floor to improve flow to the rear of the car.
This has been assisted by the revisions made to the shape and depth of the floor channel and by raising the cooling outlet bodywork above, all of which help ease the transit of flow into the central section of the car.
Other key changes
It was the front of the car that drew most of the attention when the SF21 was unveiled by Ferrari ahead of pre-season testing, with the team making some substantial changes to the nose, even though it didn’t have the tokens available to introduce an entirely new structure.
The facelift includes a narrower front wing pillar arrangement, which allows it to have the more classically side mounted cape that we see elsewhere on the grid.
Meanwhile, it has installed a quartet of chassis fins either side of the ‘S’ duct outlet too, having previously favoured having none at all. In fact the SF1000’s ‘S’ duct was more prohibitive in this respect as it utilised a hood, rather than firing the airflow directly out of the wedge created by the installation of the nose onto the chassis.