hood to windshield cowl.
 

I've seen the aerodynamically useless wiper cowl covers that Lund sells but has anyone in here made a deflector or cowl of some kind to help with the high pressure area at the base of the windshield?

You would actually want to promote flow from your engine bay out of the cowl, exhausting hot air that can then help depressurize that region. This could help minimize the air from becoming excessively turbulent in that hood to windshield region. I'm only assuming that part covers that area completely?

You would actually want to promote flow from your engine bay out of the cowl, exhausting hot air that can then help depressurize that region. This could help minimize the air from becoming excessively turbulent in that hood to windshield region. I'm only assuming that part covers that area completely?

http://ecomodder.com/forum/member-ae...od-blister.jpg

This was done by a respected member of this forum. This is in progress. I'd show a picture of it at Bonneville, but I'd have to upload it. Also:

http://www.reliableresin.com/images/...amaro_cowl.jpg

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! :)

I'd rather get a single-arm standing wiper instead of a cowl, but it's actually a good aerodynamic solution in spite of decreasing the visibility a little.

You would be amazed at how many aftermarket sheet metal producers just can't get their panels to fit. Some would say that it's because the surrounding parts are not properly aligned, however could you say that about hail damage?

Bumper covers, forget it, might as well plop down the extra cash for OEM.

regards
Mech

On the rangers there isn't any engine air coming out behind the hood. It seems to go under or through the wheel wells.

many of the aftermarket body companies

I put an aftermarket hood on my 94 camaro
the first one didn't have a straight edge on it at all
(body shop said 12-15 hours to make it ready for install (that was more than the cost of the hood))

I returned it and got one from another manufacturer (almost perfect)

The remit was "...but has anyone in here made a deflector or cowl of some kind to help with the high pressure area at the base of the windshield?". Thanks for the supporting detail. The point I didn't make would be that the convex curve starts at the front of the hood, unlike little ducktails just ahead of the wipers.

At 1/25th scale tolerances can be a problem. It's all in the molds; they have to be made to a higher level of precision than the finished product. Precision is the target that accuracy aims at.

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?

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.

cowl/hood blister
 

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.
http://i1271.photobucket.com/albums/...2/HPIM1874.jpg

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.

http://ecomodder.com/forum/member-fr...ve12d2-549.jpg

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

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

Ant Farm
 

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