April 15, 2020
Atlanta, Georgia. More powerful, dynamic and comfortable than ever before: the new 911 Turbo S sets new standards in many areas. That is also true for the adaptive aerodynamics, which Porsche has further enhanced for its flagship 911 model. Porsche Active Aerodynamics (PAA) adapts the aerodynamic characteristics of the vehicle even more precisely to the specific 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 aerodynamic 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 to achieve a higher top track speed and lower fuel consumption, while a high amount of 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 many driving situations.”
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 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 realization 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 contributes to 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 375 lbs.
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 cooling air flaps: continuously adjustable
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 fascia. They are continuously adjustable and control the cooling air input 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 43 mph. This achieves a consumption benefit in daily driving operation. At the track speed of 93 mph, the flaps open linearly to achieve the optimum aerodynamic 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 is pressed.
The front spoiler: pneumatic actuation of individual segments
The active front spoiler of the 911 Turbo has been significantly enhanced. The effective aerodynamic area has been increased compared with the predecessor. Extension and retraction can now take place in a shorter time with lower pressure. Three segments can be inflated separately with the help of actuators. The two outer actuators always function in sync. The front spoiler is made of a flexible plastic (elastomer) and can be rotated so that the middle segment can be retracted or extended when the outer segments are extended. There are several layers of adjustment:
• In the basic position, the spoiler lip is completely retracted and is fixed in position by the preload of the elastomer and by magnets on the underbody of the 911 Turbo S.
• In Speed position, only the two outer areas of the lip are extended. More air is routed around the body and the lift at the front axle is reduced.
• In Performance position, all three segments of the lip are extended. This position offers performance-oriented aerodynamics with maximum possible downforce on the front axle. In this position, the embossed ‟911 turbo S” logo is also visible in the middle of the spoiler lip.The control unit and air compressor are installed at the side of the luggage compartment. The pneumatic module is more compact than on the predecessor making the luggage compartment 0.1 cubic feet larger than before. The variable front spoiler lip also increases the front overhang angle and contributes to everyday usability: the ground clearance is higher in the basic position, and is therefore suitable for parking or clearing speed bumps.
The rear wing: now with even more functions
Lightweight construction is used on the rear wing: the distinctive Turbo feature weighs 440 grams less than the corresponding component of the predecessor, but has an 8 percent larger effective area. The basis of the wing is a foam core with forged inserts. The structure consists of an upper side with two layers of carbon fiber reinforced plastic (biaxial CFRP fabric) and a lower side with one layer of glass fiber reinforced plastic (triaxial GFRP fabric). Electric adjustment of the wing – which can be extended and tilted – is performed primarily depending on the speed and selected driving mode.
Depending on the driving modes, there are now additional positions as well as the familiar Speed and Performance positions:
• The Eco position with retracted wing is now available over a large speed range so that the vehicle can be driven with lowest possible drag.
• The Performance II position with reduced angle of attack for track speeds above 161 mph reduces drag and decreases the load on the tires on the rear axle: this made it possible to avoid increasing the tire pressure. The advantage of these measures is high tire potential in terms of longitudinal and lateral dynamics for driving performance and particularly sporty vehicle operation, such as on race tracks. Everyday usability and driving comfort also benefit from the adapted tire pressure.
• In the second new wing position Wet, the wing is well-extended but is not yet tilted. In combination with the completely retracted front spoiler lip, the aerodynamic balance is shifted towards the rear axle when Wet mode is activated. The result is higher rear end and driving stability, ensuring greater safety on wet road surfaces.
The new functions: Wet mode and airbrake
With the new Wet mode, the focus is on driving stability in wet conditions. If the sensors equipped as standard in the front wheel housings detect a significantly wet road surface due to spray that is swirled up, a corresponding message is displayed to the driver in the instrument cluster. The driver can then manually activate Wet mode by means of a rotary switch on the steering wheel. In addition to the above-described adaptation of the aerodynamic components, all relevant control systems are also set to maximum driving stability.
The new airbrake function is activated automatically in the event of full braking at high speeds. The front spoiler and rear wing are then moved to the Performance position. The higher drag and increased downforce can reduce the braking distance. Driving stability is also improved during braking.
The control strategy: wide aerodynamic spread
Configurations at a glance:
|Porsche Active Aerodynamics (PAA)||Front spoiler lip||Rear wing|
|Position/ function||Driving mode||Speed||Outer segments||Middle segment||Extension height||Tilt angle|
| Basic position
|Performance I||Sport Plus||Extended||high||large|
|Performance II||Sport Plus||Extended||high||medium|
Established in 1984, Porsche Cars North America, Inc. (PCNA) is the exclusive U.S. importer of the Porsche 911, 718 Boxster and 718 Cayman; Macan and Cayenne; Panamera; and Taycan. Headquartered in Atlanta, Georgia, since 1998, PCNA is also home to the first Porsche Experience Center in North America featuring a module-based 1.6 mile driver development track, business center, and fine dining restaurant, 356.
The company operates a second Porsche Experience Center near Los Angeles. That 53-acre complex features a driver development track with eight educational modules totaling 4.1 miles, a business center, and Restaurant 917. PCNA supports 192 independently owned and operated Porsche dealerships in the U.S., including supplying parts, service, marketing, and training. They, in turn, work to provide Porsche customers with a best-in-class experience that is in keeping with the Porsche brand's 70-year history of leadership in the advancement of vehicle performance, safety, and efficiency. PCNA is an indirect wholly-owned subsidiary of Porsche AG, which is headquartered in Stuttgart, Germany.
At the core of this success is Porsche's proud racing heritage that boasts some 30,000-plus motorsport wins to date.
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