To: dakota@csclub0.cs.fredonia.edu@INTERNET; edtrax@dedot.com@INTERNET;
TeamGTZ@aol.com@INTERNET
From: Clement_D on Mon, Jul 22, 1996 8:22 AM
Subject: RE: Dakota aftermarket stuff
From: TeamGTZ@aol.com@INTERNET on Sun, Jul 21, 1996 7:16 PM
>In a message dated 96-07-20 16:25:14 EDT, edtrax@dedot.com (Ed
Traxler)writes:
>
>>Anybody know problems with
>>positioning hood scoops/cowl induction for the Dakota?
>>
>>PS I just think a cowl induction hood scoop would look cool.
>>
>>
>I agree that it would look cool, improve performance, and shed some excess
>weight (fiberglass hood), the problem is, as far as I can tell, there's
only
>one company that makes CI hoods for the Dak, and it's for pre-92 trucks
>only!! (god only knows why!) I saw one guy at a truck show who bought a
>fiberglass cowl and cut the hood and grafted on the fiberglass piece. It
>looked pretty sharp. He put the cowl all the way aft on the hood, right
next
>to the windshield. It looked "stock" and apparently worked. As far as I
>know, the slight vacuum caused by the raised cowl part of the hood, coupled
>with the air "damming" up at the windshield forces air underneath the cowl,
>and into the engine bay. (I know, not very technical explanation, but I got
>my info from a gearhead, not an aerodynamics engineer!)
The base of the windshield is a high pressure point, that's why the rear
facing scoops work (look at a NASCAR car, they just have a hole at the
windshield base). There is no vacuum created by air flowing over one of
these cowl scoops, there may be a slight reduction in air pressure close to
the surface as the air velocity increases going over the scoop but it does
not go below atmospheric pressure. If the opening to one of these cowl
scoops is not close to the windshield there could be a low pressure area
created at the opening resulting a a negative impact on air flow into the
engine.
If you are looking for a performance increase you would be better off with a
forward facing scoop. At legal driving speeds this would be much more
effective and would more than offset the aerodynamic penalty.
Dave Clement
ps: If you have a bug deflector on the front edge of the hood you would
likely negate any improvement either scoop design might provide.
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