“What is DRS?” The Racing Equivalent to “Name 3 Songs by that Band”

Image Citation: [1]

Written by Hailey Stone ‘28

Edited by Joanna Sohn ‘28

The science behind the Drag Reduction System (DRS): when it can be used, how it works, and recent controversies.

In racing, everything is about hitting the absolute limits of possibility. However, one tricky point of the machinery is that on the straights, the car needs to cut through the air, while on the corners, it requires downforce to increase grip and prevent spinning out. A place where these two areas come to clash is in the rear wing. The natural design of the rear wing curves upward to create downforce, but this design also creates drag on the straights. To address this, the drag reduction system (DRS) was implemented.

DRS debuted in 2011, ushering in a new era of racing. When activated, DRS shifts the rear wing flap into a horizontal position, reducing drag by 20% and allowing for a possible overtake [2]. Some Formula 1 tracks, such as Monaco and Hungary, are tighter and prove more difficult for drivers to overtake. This is where DRS is necessary.

Figure 1: Monaco Grand Prix Circuit [3]	Figure 2: Hungarian Grand Prix Circuit [3]

Whereas the leading driver would normally gain an advantage accelerating out of the turn first, DRS evens the playing field and allows drivers to compete more aggressively to change the results of the race [4]. Another important note to elaborate on is the specific conditions in which DRS is allowed. While DRS is meant to add an aspect of competitiveness to the race, there must be rules to ensure it remains fair. In order to activate DRS, a driver must be within one second of the driver in front of them at the DRS detection zone. These zones are located before a long straight in which a driver may gain an advantage to pass. Furthermore, DRS is not allowed in the first three laps of the race or the first lap after a safety car. In such situations, cars are more packed together, and allowing DRS would only increase the high number of accidents that occur at these times.

Figure 3:

The rear wing flap while closed (most of the time) vs open (DRS activated) [5]

The key function of DRS is that it alters the angle of the rear spoiler (an aerodynamic device that alters the airflow), which changes the car's aerodynamic profile [5]. Similar to the flaps that can be seen opening and closing on an airplane's wing, DRS works through a series of hydraulic tubes, rods, and actuators. The only difference is that while aircraft have large wings to hide the mechanical workings, F1 cars are forced to work with limited space. With the intricate designs and technology involved, it is important that the setup accounts for possible issues. For example, the flap must be manufactured to lift from the trailing edge of the wing, ensuring that in case of failure, the wing returns to its natural position, maintaining the legality and safety of the car as it takes the next turn [4].

Figure 4: Maximum speed of 160 km/hr. DRS remains closed at an angle of -40 degrees [6].	Figure 5: Maximum speed of 320 km/hr. DRS opens to an attack angle of 0 degrees [6].

With such a fantastic device as DRS, there is no doubt that teams would wish to implement this kind of movement in the rear wing at all times. However, per FIA rules, the wings generally should not bend besides in an accident, for safety reasons. This leaves some room for interpretation, and in recent months, F1 racing team McLaren has been called out for potentially stretching these limits too much. While McLaren passed all FIA tests, images show their rear wing displaying a small flex that allows gaps in the wing to form in non-DRS zones. For this reason, it has been coined “the mini DRS.”

Many teams like Ferrari and RedBull called McLaren out on this and requested the FIA take a closer look. While no further action was taken against the team, McLaren agreed to make some changes to their design [6]. It is important to note that this is the nature of F1, and while it may come across that McLaren is in the wrong here, every team is taking every opportunity to excel and have the best upgrades. Just like DRS was created in 2011 to make the sport more competitive, the teams are aiming to do the same every day. Maximizing the limits is the name of the game, and F1 teams are here to play.

Figure 6: Side view of the McLaren F1 rear wing [7].	Figure 7: Rear view of the McLaren F1 rear wing [7].

References

1. Hall S. F1 DRS Explained: What is Drag Reduction System and how does it work? [Internet]. GPFans. 2024. Available from: https://www.gpfans.com/en/f1-news/102569/drs-f1/

2. Loução R, Duarte GO, Mendes MJGC. Aerodynamic Study of a Drag Reduction System and Its Actuation System for a Formula Student Competition Car. Fluids. 2022 Sep 16;7(9):309.

3. FIA. F1 [Internet]. Available from: https://www.formula1.com/

4. Collins S. DRS: The Drag Reduction System explained [Internet]. Racecar Engineering. 2011. Available from: https://www.racecar-engineering.com/articles/f1/drs-the-drag-reduction-system/

5. Physics of Formula 1 [Internet]. Wordpress. Available from: https://physicsofformula1.wordpress.com/modelling-drs/

6. Lekhnath Gyawali. CFD ANALYSIS OF DUEL ELEMENT REAR WING OF A F1 CAR. 2022 [cited 2024 Nov 19]; Available from: https://rgdoi.net/10.13140/RG.2.2.17772.44167

7. Straw E. McLaren must adapt controversial rear wing [Internet]. The Race. 2024. Available from: https://www.the-race.com/formula-1/mclaren-must-adapt-controversial-f1-rear-wing/