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Old 12-23-2010, 03:44 PM   #327 (permalink)
aerohead
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fin

Quote:
Originally Posted by euromodder View Post
If we start from the basic Insight, then adding a tail extension (i.e. more area at the rear) surely is going to shift the resulting pressure point for a sidewind further aft.
Fortunately, the design of the extension is such that the wind can't get too much hold on it.
The CoG is also slightly moving aft by adding more weight at the rear, so the effect of having more area at the rear is at least partly compensated for.

The extreme situation would be adding so much area to the rear, that the car starts to severely weathercock and would become undriveable.
This is a situation where one might end up by adding a vertical fin to the extension.
It'd add a lot of area for a sidewind to work on and cause additional stress on the boattail's structure.
Same goes for the additional weight of a vertical fin.

I wouldn't do it.
The reason I threw a caution flag out on the play, was that Jim was already reporting that the front was 'going first' on the ice,something indicative of forward COP.
It has been reported by others that it's virtually impossible to ascertain the position of COP without a wind tunnel,so it's an especially tricky issue for us amateurs.
Since fins have often been used as a palliative in these situations,and since Morreli has demonstrated that behind-the-wheel fairings can perform the fin function killing two birds with one stone,it might be a talking point.
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