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Old 10-26-2011, 03:50 PM   #169 (permalink)
some_other_dave
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Quote:
Originally Posted by kach22i View Post
On the old air cooled 911's, the tea tray and whale tail type spoilers add little down force, and don't help out the drag very much either. What they do best is to allow the cooling fan to draw in air from the top better by altering the pressure zone above the intake vent.
The "duck tail" spoiler reduced lift in the rear, to the point where the factory required people to use front spoilers if they added the duck-tail. It also decreased the drag of the car, most likely by making the air flow over the car more closely approximate the "template".

I am less certain of this, but the tea-tray and whale-tail were used for the same purposes, reducing lift and reducing drag. They were better at one or both than the duck-tail, so the race cars were equipped with them and the duck-tail was phased out.

The other two tails also provided room for the intercooler that was used on all but the first 911 Turbos, which contributed to its popularity.

-soD
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