997 Trivia Post
05-29-2009, 07:58 PM
#1
Poseur
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997 Trivia Post
Since Abe started this all by proclaiming his ignorance of the second LED brake light on the trailing edge of his 997 tail, I think perhaps it's time to start and renew a thread on some of the more obscure things we have discovered about the 997 which often takes some time to discover for one's self.
One of the most obscure, which I alluded to earlier, is that the cabriolet tails go up 20mm higher than those on the coupes. This is to compensate for the difference between the rooflines and drag of the fabric vice steel roof.
Lesson No. 2:
Aerodynamics and air routing
During development of the new vehicle it became obvious that further enhancement of the aerodynamic properties of the 911 Carrera S was required. The objective in doing so was to take account of the increased performance by reducing the aerodynamic lifting forces and at the same time to further reduce the drag coefficient (despite the higher cooling air requirement for brake and engine cooling).
The result was a significant improvement in aerodynamic coefficients in comparison with the previous model. The drag coefficient was reduced to cw= 0.28 (previous model 0.30) and the lift coefficients at the front and rear axle were each reduced by 0.01 to cAV= 0.05 und cAH= 0.02 respectively. These values cannot be matched by any of our international competitors. The main challenges facing the aerodynamics engineers of the 911 Carrera were:
• The larger frontal area, caused by flared wheel housings and wider tires in particular
• The lower lift coefficients and hence the increased wheel load
• The engine’s higher cooling air requirement
• The higher cooling air requirement of the brakes due to the increase in performance
• The more efficient cooling of the gearbox, and of the 6-speed manual gearbox in particular, due to the higher engine output optimization of the outer skin
The main starting points when it came to optimizing the outer skin, apart from the front and rear of the vehicle, were the wings and front side sections. Particular attention had to be paid to aerodynamic integration of the flared wheel housings. The sweep and the radii of the front apron have been optimized to produce an aerodynamically efficient air flow at the front end and significantly better prerequisites for cooling air flow without affecting the styling of the outline. The lateral openings on the front apron required to supply cool air to the radiators have also been carefully optimized and integrated in the front end concept. The lateral front apron radii and wheel houses are designed to shield the front wheels from the air flow in an optimum manner and to provide much greater wheel housing ventilation. These measures reduce drag and, by providing greater wheel housing ventilation, also reduce lift at the front axle.
One of the most obscure, which I alluded to earlier, is that the cabriolet tails go up 20mm higher than those on the coupes. This is to compensate for the difference between the rooflines and drag of the fabric vice steel roof.
Lesson No. 2:
Aerodynamics and air routing
During development of the new vehicle it became obvious that further enhancement of the aerodynamic properties of the 911 Carrera S was required. The objective in doing so was to take account of the increased performance by reducing the aerodynamic lifting forces and at the same time to further reduce the drag coefficient (despite the higher cooling air requirement for brake and engine cooling).
The result was a significant improvement in aerodynamic coefficients in comparison with the previous model. The drag coefficient was reduced to cw= 0.28 (previous model 0.30) and the lift coefficients at the front and rear axle were each reduced by 0.01 to cAV= 0.05 und cAH= 0.02 respectively. These values cannot be matched by any of our international competitors. The main challenges facing the aerodynamics engineers of the 911 Carrera were:
• The larger frontal area, caused by flared wheel housings and wider tires in particular
• The lower lift coefficients and hence the increased wheel load
• The engine’s higher cooling air requirement
• The higher cooling air requirement of the brakes due to the increase in performance
• The more efficient cooling of the gearbox, and of the 6-speed manual gearbox in particular, due to the higher engine output optimization of the outer skin
The main starting points when it came to optimizing the outer skin, apart from the front and rear of the vehicle, were the wings and front side sections. Particular attention had to be paid to aerodynamic integration of the flared wheel housings. The sweep and the radii of the front apron have been optimized to produce an aerodynamically efficient air flow at the front end and significantly better prerequisites for cooling air flow without affecting the styling of the outline. The lateral openings on the front apron required to supply cool air to the radiators have also been carefully optimized and integrated in the front end concept. The lateral front apron radii and wheel houses are designed to shield the front wheels from the air flow in an optimum manner and to provide much greater wheel housing ventilation. These measures reduce drag and, by providing greater wheel housing ventilation, also reduce lift at the front axle.
05-29-2009, 08:02 PM
#2
Banned
05-29-2009, 11:33 PM
#3
Poseur
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Lesson #3. A/C and air recirculation.
Recirculation mode 1 – Mode of functioning of manual recirculation mode--The fresh/recirculated air distributor flap can be activated at any time to prevent odor nuisance. However, recirculation mode is limited to max. 3 minutes when the air conditioning compressor is switched off (ECOnomy mode).
2 – Mode of functioning of automatic recirculation mode--At exterior temperatures of >26 °C or 79 °F, recirculation mode is selected automatically by the program after a ventilation time of 30 seconds in order to accelerate the cooling-down phase - with the air conditioning switched on.
Recirculation mode 1 – Mode of functioning of manual recirculation mode--The fresh/recirculated air distributor flap can be activated at any time to prevent odor nuisance. However, recirculation mode is limited to max. 3 minutes when the air conditioning compressor is switched off (ECOnomy mode).
2 – Mode of functioning of automatic recirculation mode--At exterior temperatures of >26 °C or 79 °F, recirculation mode is selected automatically by the program after a ventilation time of 30 seconds in order to accelerate the cooling-down phase - with the air conditioning switched on.
