List,
Third installment...
The next season, 2002, I bought a Harwood scoop with a 3 7/8 X 13 3/4
opening. (More than 52 sq. inches) We mounted this scoop down on the
hood to pickup laminar air. We were still getting the same negative
readings we got with the small opening on the previous scoop. In 2003,
raised the scoop up 3 inches above the hood. With both these scoops we
had sealing issues because the scoop is mounted on the hood and the air
box is on the engine. I believe that the seal is reasonably good at
present. We are now reading a negative 1.5 - 2.5 in.hg.. On our second
run at the World Finals, 2003, we plugged the reference tube and read a
positive 5.95 in hg (2.92 psi) @ 7500 rpm (220 mph) and 5.64 in hg (2.77
psi) @ 8375 rpm (241.5 mph) in the scoop.
I know that the conventional wisdom says that a small opening works best
at Bonneville. I have talked with several engineers that promote this
idea. I don't disagree with this as theory, but what has worked for me
is a larger opening. I realize that this may be because of the scoop
location, the air being turbulent, or a number of other reasons. I will
still continue to experiment. This next year will probably see yet
another scoop, probably higher off the hood. The success that I have
enjoyed in this sport has come, mostly, from doing what doesn't work!
Tom, Redding CA - #216 D/CC
ELLEN WILKINSON FOR wrote:
> One reason for the small air scoop inlet on the 998 car might be when Terry
> was running the 444 car Rick Vesco designed a very similar looking scoop with
> a bigger inlet. I don't remember the year or exact speed but at about 280- 300
> at about the 5 mile the larger scoop packed enough air in to blow part of the
> body off.
> Gary Wilkinson
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