In Formula 1 racing, cars are designed with numerous aspects in mind: power, steering capabilities, aerodynamics, downforce, safety and so on. As the years progress, different technologies, upon approval from the FIA, can be used by the competing drivers to gain an advantage from the opponents. One of these is called the Drag Reduction System, or DRS.
DRS was first introduced in Formula One in the 2011 season. The way it works is simple: the rear wing of an F1 car consists of a main plane and a flap. When the driver presses a button on their steering wheel, the flap on the rear wing of the vehicle would adjust. The rear wing would then have a more horizontal alignment, thus reducing the vehicle's opposition drag. As a result, the car would then be experiencing less drag at the cost of lower downforce. The vehicle would then be able to achieve faster acceleration as well as higher top speeds. A light on the dashboard of the vehicle would indicate when the system is enabled. Releasing of the button on the steering wheel or stepping on the brakes would deactivate the system.
The primary purpose of the DRS is for overtaking opposing vehicles, but there are rules and limitations in F1 racing to utilizing the technology and they are as follows:
The system may only be used in DRS zones of the track, as specified by the FIA.
It may only be used by a racer who is following a car in front.
The follower must be at most one second behind the leading or defending car.
The system may not be used in the first two laps of the race; it may also not be used in the first two laps following a restart or a safety car appearance.
The car that is being followed may not use the system, unless the leading car is also following a car in front that is at most one second ahead.
Proper usage of the DRS can result in significant improvements in the car's lap times. Lowering of the flaps can increase top speed of the car by up to 12 kph and a half second improvement in race total lap time. The drivers may utilize the system without restrictions during the practice and qualifying rounds of the race.
As mentioned beforehand, using the DRS would result in the vehicle experiencing a lower downforce. With F1 cars going at incredibly high speeds, handling and cornering would require that the vehicles stick to the ground, which is why downforce is necessary. Needless to say, the drivers would not use the system when making turns on the track. Either way, the DRS zones on the track are usually appointed along straight areas on the track, which have been increasing in quantity over the recent years.
For a more detailed understanding of DRS, including an analysis of the system's performance as well as its design and manufacturing, visit Racecar Engineering's webpage.