Hey, Rick, glad to hear from you! Yep, putting the scoop into a high
pressure area is what it is all about. And you are right about the boundary
layer lifting off and the air getting turbulent as speed increases. One of
those things you gotta watch out for as you try for faster speeds. Even the
angle of the scoop opening relative to the surface under neath it is
important. Lots of things to consider than just size. Glad to se that you
are being innovative especially in the charge air cooling... cool air is
more dense, more fuel can be added, ergo more power. And it is linear! a 2%
change is air density means a 2% change is power. So cool that air! Enen on
N/a cars and bikes (if possible). If a scoop is working too well, I'd think
it would go lean, not fat. So my thought is it is not in the right place for
the speed or is not sized correctly...
Anyhoo, I love to hear from you experienced racers! Oh, what is HDRA? I know
what NACA duct are, but...
mayf
----- Original Message -----
From: "Rick Byrnes" <Rick@rbmotorsports.com>
To: "DrMayf" <drmayf@teknett.com>
Sent: Tuesday, January 29, 2002 7:11 PM
Subject: Re: Scoop Size (see size does count!) Chuckles...
> Thanks Mayf
> I played a little last night and find that your numbers are sort of on the
> number :=D. I have chosen a slightly larger scoop because of the shape
of
> the car and where the air inlet is relative to a high pressure area. On
the
> Merk, I had the air inlet at the radiator support which of course is the
> largest highest pressure on the vehicle. On the lakester, air being
> deflected by the windscreen separates from the body and must be picked up
> about 6 inches above the skin. (minimum) Consider also charge air
cooling
> even for N/A motors. It works. Inlet air going thru a small radiator
with
> ice water flowing, then directly in the inlet. Photo of Merk attached.
> The big guns say that as you go over 250 and approach 300 the air changes
> and lifts even higher off the body. Engines that seem calibrated fine, go
> really rich in the 5. Don't hurt the motor much, but it is irritating.
> Some think it is the scoop working too well, but others think the air is
> missing. There is a wonderful mysterious world out there, and I'm gonna
> find out the hard way. My aero guy says NACA ducts, the fast guys say
HDRA.
> They go fast. My aero guy only does in an airplane. And he is a car
> guy.....
> Keep it up. I like the discussions you initiate. I Don't contribute
much,
> but I'm always lookin.
> Thanks...
>
> Rick
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