hood to windshield cowl.

[Xist]

As I understand, one of the problems with trying to mitigate the low-pressure area at the base of the windshield is that is where the cabin gets its air. Having engine air exit there makes sense, unless it proceeds into the cabin.

Could you set it up so that your engine air is ducted at a 45° towards the passenger side mirror (or where it would be) and the cabin air is routed at a 45°, in the general direction of the driver's side headlight?

[Frank Lee]

Guys guys guys... do a search or something on this. The cowl area has HIGH pressure, think of cowl induction hoods- yup, the air goes INTO the cowl induction area due to the pressure. But even more importantly, the cowl is NOT an aerodynamic trouble spot.

[aerohead]

Originally Posted by Xist

Freebeard, as I recall, Aerohead did not notice an improvement. It really seems like it would obstruct his vision, but that would entirely depend on his height. Driving my Subaru, I have thought that I could do the same thing, but I am 6'2".

I really want to know who made hoods that did not fit!

Yes,I have no A-B-A testing which demonstrated any improvement.
*There is data which shows a drag reduction for the downward parabolic curvature from Hucho and Fiat.
*And it should reduce the pressure peak at the cowl (which I notice from diminished passive ventilation capacity)
*And it changes the effective angle between the cowl/windshield intersection.
*In a rain,the air will push water all the way uphill to the trailing edge of the blister which suggests that the TBL is receiving copious amounts of kinetic energy.
* I suppose that all I could say about the blister,is that it doesn't hurt anything.
*Without it,the hood collapses in front of the cowl and booms(adhesive gave up and sheetmetal is no longer bonded to to underlying framework).
*My racing bucket is mounted a bit high and at 6' 1" I can look right over the blister except along the passenger side hood top (not a problem so far)
*Lastly,I covered the blister-to-windshield gap completely at Bonneville with cardboard and duct tape and saw no change in top speed at 105-mph,measured to 1/1000 of a mph.

[freebeard]

There ya' go.

What does work is a deeply curved windshield. Many modern cars, e. g. Loloa T70 & etc., have it. The curved screen on a Superbeetle is good for 5mph additional top speed on the salt flats. Look at the Volkhart-Saggita for example. The cabin is almost a separate form and the cowl is kept very low so air can roll off to the sides.

[Frank Lee]

I'd say the curve-screened VW has the aero advantage due to better flow at the A-pillars, not the cowl.

[freebeard]

Precisely. It's just not as easily achieved. Perhaps done best by Ant Farm's Media Burn:

http://www.youtube.com/watch?v=U53-Sfnqwss

[aerohead]

Hope Cadillac chiefs have seen it.They could modify a CTS into a C'TV'.