Aerodynamic question for 986 guys who track a lot

[atmorris]

Question for anyone who has a 986, tracks it now and then, and has changed the front bumper from stock type to a GT2 or turbo type.

From what I can see, the stock configuration on my '03 (or an '04) states a drag coefficient of 0.31 - very sleek. The GT2 or 911 Turbo, while I recognise that it is a different body style, states a drag coefficient of 0.34 with the wing up and 0.31 or 0.30 with it retracted. This data seems consistant throughout the model line, so the frontal area configuration being base stock, GT2, Turbo, or GT3, does not seem to affect the drag coefficient at all. SO, it looks like it is a reasonable assumption that changing the 986 front bumper to a GT2 or Turbo style bumper will not change the drag coefficient, and therefore will not affect realized top speed.

Since none of us are Aerodynamicists, I'll put the question to those of you who have actually have ran a 986 in both configurations at high speeds (on a track I hope), do your experiences support this ?

[Topless]

Question for anyone who has a 986, tracks it now and then, and has changed the front bumper from stock type to a GT2 or turbo type.

From what I can see, the stock configuration on my '03 (or an '04) states a drag coefficient of 0.31 - very sleek. The GT2 or 911 Turbo, while I recognise that it is a different body style, states a drag coefficient of 0.34 with the wing up and 0.31 or 0.30 with it retracted. This data seems consistant throughout the model line, so the frontal area configuration being base stock, GT2, Turbo, or GT3, does not seem to affect the drag coefficient at all. SO, it looks like it is a reasonable assumption that changing the 986 front bumper to a GT2 or Turbo style bumper will not change the drag coefficient, and therefore will not affect realized top speed.

Since none of us are Aerodynamicists, I'll put the question to those of you who have actually have ran a 986 in both configurations at high speeds (on a track I hope), do your experiences support this ?

Just no way to accurately measure drag without wind tunnel testing. Too many variables out on a track in different cars to even make a guess. No track in the US has a straight long enough to reach top speed in a 986 except Bonneville salt flats. From my experience with experimental aircraft, the nose with the finest, cleanest entry is usually the lowest drag. From a purely visual guess... the stock nose on a 986 is the cleanest. Will you ever notice the difference? Unlikely.