The FIA and Formula 1 management made changes to the aerodynamic regulations ahead of 2021 in a bid force a 10% reduction in overall downforce – enough they believe to allow the tyres to cope with the ever-increasing downforce the cars deliver.

The most significant contributor to the forecasted 10% drop in downforce is a set of new floor regulations. The cars see a diagonal cut in the floor ahead of the rear tyres, reducing the width at the trailing edge by 100mm on each side.

Red Bull Racing RB16B. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

Additionally, the rules prevent the designers from having any fully enclosed holes in the floor to manipulate airflow through slots, holes, and shaped aerodynamic furniture in that region. These changes decrease the floor’s working area used to generate downforce from under the car and reduce the team’s ability to seal the floor to work the diffuser as effectively as possible.

AlphaTauri AT02 floor detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

Additionally, it will be harder to control rear tyre wake influence on the diffuser stream and control rejected air from the rear tyres without the slots, holes, and other aerodynamic fixtures seen in 2020. The loss of these features also reduces the control of the aerodynamic consequences of the varying sidewall bulge and contact patch squirt (loss ejected by the tyre as it contacts the ground).

Mercedes AMG F1 W12 floor detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

The allowable flex and subsequently the floor’s minimum stiffness has also been adjusted for 2021 to reduce the use of it as a movable surface to influence aerodynamics. The floor is allowed to flex up to 8mm vertically when 500N of load is applied to it – a reduction from 10mm of flex permitted in the 2020 regulations with the same load.

Red Bull Racing RB16B floor detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

The diffuser has also been amended to lessen its ability to create downforce with the height of the boundary controlling vertical elements required to be 50mm shorter this season when compared to last. Winglets mounted in the lower half of the rear brake duct have also changed and may now be just 2/3 of the 2020 width, restricted to no wider than 80mm for 2021.

Alpine F1 Team A521. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

As Formula 1 pre-season testing is underway, Racecar Engineering gets it’s first look at the various solutions to these new regulations as the cars take to the track for the first time in 2021 specifications. See some of the floor solutions below:

Alfa Romeo Racing C41 detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

Alpine F1 Team A521 detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

McLaren MCL35M detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

AlphaTauri AT02 detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

Williams Racing FW43B detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images

 

Red Bull Racing RB16B detail. Formula 1 Testing, Sakhir, Bahrain, Day One. Photo: XPB Images