Porsche Active Aerodynamics PAA on 992 Turbo S Porsche 911 Turbo in English and in German

Auf Deutsch: 6:49 Porsche Active Aerodynamics (PAA) adapts the aerodynamic characteristics of the vehicle even more precisely to the driving situation, speed and selected driving mode. PAA celebrated its world premiere in the previous generation of the 911 Turbo launched in 2014. All model lines from the 718 through to the Panamera and Taycan now feature active aero-dynamic elements.

“No other sports car reacts to different situations with such aerodynamic flexibility as the new 911 Turbo S. We aerodynamic engineers are normally faced with a dilemma: a low drag coefficient is desirable for maximum speed and low consumption, while a high downforce is advantageous for driving dynamics. However, the two characteristics contradict each other,” explains Dr Thomas Wiegand, Head of Aerodynamics Development at Porsche. “PAA resolves the conflicts between these different aerodynamic goals. The comprehensive expansion of the intelligent system in the 911 Turbo S makes it possible to achieve a much larger spread between the aerodynamic configurations for optimum driving dynamics and minimum drag. What is more, there is increased potential for the aerodynamic components to support specific driving dynamics demands in every driving situation.”

The active cooling air flaps are new. Together with the variable front spoiler lip as well as the extending and tilting rear wing, the new top-of-the-range model therefore features three active aerodynamic components. On top of the basic aerodynamic configurations of the 911 Turbo, namely PAA Speed and PAA Performance, this now permits realisation of an Eco configuration.

PAA has also been extended to include a Wet Mode function, which moves the aerodynamic balance towards the rear axle for greater driving stability in wet road conditions, as well as the airbrake function, which produces higher drag and greater downforce in the event of full braking at high speed and therefore results in a shorter braking distance and greater driving stability. PAA is also used for adaptation to the changed air flow around the vehicle when the sliding roof or convertible top is open. This means that there are a total of eight different aerodynamic configurations, which are each described by a specific combination of the active aerodynamic components.

Improvements have not just been made in adaptation to the specific requirements in driving operation, but also as regards the aerodynamic properties themselves: the newly designed active front spoiler and rear wing have increased the downforce by 15 percent to guarantee enhanced driving stability and dynamics at higher speeds. The maximum downforce in the Performance position (Sport Plus mode activated) is now around 170 kg.

The drag coefficient (cd) of the 911 Turbo S varies depending on the aerodynamic setting. The most efficient configuration with the minimum cd value of 0.33 is achieved with closed flaps and retracted front and rear spoilers.

The newly developed controlled cooling air flaps permit a lower driving resistance and thus reduced fuel consumption. The flaps are located in the right and left air intakes of the front apron. They are continuously adjustable and control the cooling air throughput through the radiators.

An intelligent energy management system is responsible for achieving a balance
between the current cooling requirement, the electric power required to operate the radiator fan and the aerodynamic benefit of the cooling air flaps. As a result, the cooling air flaps are closed as far as possible from a driving speed of 70 km/h. This achieves a consumption benefit in daily driving operation.

As from a speed of 150 km/h, the flaps open linearly to achieve the optimum aero-dynamic balance at high speed. Priority is also given to driving dynamics and the cooling air flaps are thus opened when the Sport, Sport Plus and Wet driving modes are active and when Porsche Stability Management (PSM) is deactivated or the spoiler button pressed.

In addition to the basic positions explained above, the PAA also reacts to opening of the sliding roof or convertible top. A distinction is therefore made between seven rear wing positions. Different equipment variants are also taken into account in the configurations for the individual positions. The control strategy also allows for whether the car is a Coupé or Cabriolet and whether a Sport Design package with different body contours is installed at the front and rear.

As early as 1971, Porsche already fitted the first front spoiler on the 911 S. This accelerated the air flow under the vehicle and guided part of the air past at the sides, thus reducing the front-end lift.
In 1972, a milestone in aerodynamic development was launched on the market with the Carrera RS 2.7, a car designed for motorsports: this was not just equipped with a low front apron, but featured a distinctive spoiler above the bootlid – the legendary “duck tail”.