This proves that a properly designed luggage carrier "trunk" if designed
with the air flow in mind could
possibly be in the air flow and help the overall over the westy top.

I believe it is the depression of the luggage rack area itself that is
causing most of the turbulence.

Even a properly shaped fiberglass "lid" over the depression would help .

Doug

----- Original Message -----
From: "Kim Brennan" <kimbrennan@MAC.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, October 18, 2004 2:51 PM
Subject: Re: aerodynamics, was: 101 MPH Vanagon!

> An excellent picture. Note that the Westy has significant turbulence
> over the top (the laminar lines break up almost immeadiately over the
> luggage rack). The passenger Vanagon (blue one) has pretty decent
> laminar flow. The Beige one has a popup top that causes a bit of
> turbulence.
>
> Reading the fine print I think it says that the CD on the blue
> passenger is 0.44, on the beige popup it is 0.45. On the westy it is
> 0.51. On the Hi-top it is 0.40 (!). On the singlecab with camper it is
> 0.45. Also appears to have the varying front area too.
>
> But not that the westy had the worse CD (and those are regular
> Vanagons, not syncros, which should have worse CD's due to increase
> ground turbulence.