James Allison, technical director of the Mercedes-AMG Formula One Team, has revealed that the biggest area of technical development has been adapting to the new aerodynamic rules.
In a Mercedes interview after the car launch, Allison has revealed the biggest challenge has been adapting to the new 2021 aerodynamic rules, which he says “affect the performance of the floor,” slowing the car down.
“By far and away the biggest area of development has been adapting to the new aerodynamic rules,” said Allison.
“2021 brings a profound set of changes that affect the performance of the floor. If you’re looking to slow a car down, which is effectively what the regulations changes were intended to do, modifying the floor is by far the easiest and cheapest way of achieving your objective. The floor is such an important aerodynamic component that small geometrical changes bring large reductions in performance.
“Once the rules had been established, our task was to figure out how to recover the losses brought by the changes. The rest of the aerodynamic work has been the normal fare of seeking out aerodynamic opportunity across every square centimeter of the car with particular attention to finding places where we can invest extra weight into fancier aerodynamic geometry.
“We have an additional few kilos to spend as a result of DAS being banned.
“And of course, our colleagues over at Mercedes AMG High-Performance Powertrains have been pushing hard to find gains to the Power Unit, delivering us a useful step forwards in a year where all the gains need to be packed into a single release of hardware,” he concluded.
Allison also explained the four aerodynamic changes on the 2021 car.
The triangular cut-out “is located just in front of the rear wheels, reducing the area and shape of the floor. It may not look like a big change, but the way the floor and the rear wheels interact is critically important to the performance of the car. So, removing this part of the floor has a big impact on downforce.”
The second aero change “is related to the rear brake ducts (…) these winglets generate a little bit of downforce of their own right, but their far more important role is to guide the interaction between the rear tires and the floor, helping the floor to produce far more downforce than the winglets could ever manage on their own. The span of these winglets has been reduced by a few centimeters so they don’t overlap as much with the floor as they used to, thereby reducing the performance of the car.”
“The third change is at the back of the car around the diffuser area.
“For 2021, the inboard set of strakes, the ones nearest the center line of the car, have had their bottom 50mm sawn off so that they don’t sit as close to the ground as before. By making the fences shorter, they are less effective at dividing the diffuser into separate regions and therefore less effective at controlling the rate of expansion of the air. All things being equal, this makes it harder to be greedy with the diffuser expansion, and so it reduces the downforce of the car.”
The fourth aerodynamic change “is related to the edges of the floor, near the bargeboards and the radiator air intakes. In recent seasons all the cars have sported an array of slots on the floor in this section of the car, almost looking like a Venetian blind. For 2021 the rule has changed, requiring us to seal those slots up. This reduces our ability to create downforce at the lateral periphery of the floor.”