Aerodynamic engineers will often use the expression “more downforce, less drag” to summarise their goal when developing a component for a race car. While this is certainly a good starting point, there are many other parameters and trade-offs to be considered and those will be discussed in this series of articles we are launching today.
Why higher downforce and lower drag will make the car go faster around the lap on a typical racetrack? If we assume that the driver is attempting to maximise the car’s performance, then we can say that throughout the lap the car will be either grip-limited or power-limited.
In the grip-limited sectors, the car still has engine power available but the grip level available at the contact between the tyres and the ground is the limiting factor for performance. If more grip was available then the driver would be able to achieve higher accelerations which in turn would result in shorter braking distances, higher cornering speeds and faster acceleration out of a corner.
On the other hand, in the power-limited sectors, the car still has grip available at the tyre/ground contact, but the engine power is the limiting factor. If more power was available, or less resistance for the same power, then the car would travel at a higher speed.
When a car is updated with components which generate higher downforce in the grip-limited sectors, there will be an increase in the grip levels at the tyre/ground contact, which in turn will enable higher acceleration and reduced time required to cover that sector. Likewise, if the drag is reduced in the power-limited sectors, then the car will travel at a higher speed and will be quicker to cover that sector.
So higher downforce and lower drag should indeed be a good step in terms of improving lap time, as long as it is delivered consistently across the car operating range. In our next article, we will discuss Aerodynamic Driveability and how too much variability in the aerodynamic performance will negatively affect the car performance and driver’s confidence levels.