I have a series of questions/observations on the subject of aerodynamics. And
one compaint about an lbc "god". The complaint is about Peter Egan. He has a
great article in the latest R&T about his maiden voyage in his freshly restored
MGB. My complaint is with one of the pictures and what it may imply. This
picture shows the B in front of a general store as I recall, with the top down,
and the windows UP! I always cringe when I see someone with their top down and
the windows up, regardless of the type of car. I realize this may be a
personal problem, but this combination always looks wrong to me. It destroys
the clean lines of a roadster. (This is one slight complaint I have with the
old Elans, they have a window track all the way around so the top down leaves a
chrome hoop. However, if someone has one they want to get rid of, I could
probably live with it :-)
This has raised the subject of aerodynamics. I remember reading someplace that
the BGTs had a higher top speed than the roadsters, even though the GTs are
heavier. The questions are as follows: How much impact does aerodynamics play
on our cars? I have read in a number of places that it is saves gas to run the
air conditioner than to open the windows. I have a problem with this. At low
speeds, aerodynamics has little impact on your fuel economy, so rollong the
windows down has to save gas over running the AC. However, at some speed,
there is a break even point that makes the AC the way to go. This point is
usually claimed to be less than highway speeds. However, what kind of car was
used? For a very sleek car I could see window open drag kicking in at low
speeds. However, for something like a van, (or a mini :-) the drag is so high,
that an open window might be a small component of the total drag. The last
portion is with my non-lbc. It has a sun roof that can either flip up at the
back, or slide completely into the roof for a large hole. This is on the top
of the car which would likely have smoother aerodynamics than the side of the
car. Therefor, it would seem that an open sun roof would cause more drag than
an open window, right? But what about the back flipped up option? Or am I
just providing extra down force for those high speed runs in stop and go
traffic :-) :-)
Of course since my lbc is a midget, it doesn't go fast enough to really worry
about drag and its effect on my top speed...
Octagonally yours from the big ville of Dayton, OH
MAD
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