The airbox of the new Alpine A521 driven by Fernando Alonso and Esteban Ocon is the subject of much discussion in the paddock of Formula 1 because it is far more massive than on any other race car of the current generation.
The reason for this is the rule changes for the 2021 season.
Alpine follows the design where they use higher sidepods that are heavily cut at the bottom and have only small air openings. This arrangement gives engineers more clearance between the side box and the underbody to direct the airflow specifically to the rear, where it meets the diffuser.
Alpine believes this is the more efficient approach, but it has to make compromises. And this is where the “thick” airbox with the bulky bonnet comes into play. Because: In order to create the compact side boxes, the cooling circuit had to be modified. Parts of the cooling system were reduced in size or moved to new positions within the car. Renault used this system as well, but not in such an extreme way as Alpine.
Marcin Budkowski, Executive Director of the Alpine F1 team, has explained this development and change:
“It’s a technical choice. We found that slimming the sidepods was a positive direction, which is nothing new really. So, we’ve repackaged and relocated some of the bulky things in the car and we’ve put them behind the air inlet.
“It gives a fairly spectacularly bulky shape in the car but still, we found it works for us. Yes, there are centre of gravity compromises but usually the aero performance wins over weight and centre of gravity.”