Boattail without boattailing

[drmiller100]

thanks for the link. fascinating read, and explains how to think about things.

A different outlook. If we look only at the car from the side, we think about modifying the trunk.

If we look from above the car, and down, we think about modifying the sides.

We can only modify the top once, but we get to modify each side. So, twice the benefit in working on the sides of the car.

also, there is not a successful racer of any kind in the entire world who thinks undercar air is a good thing, except those who can legally run ground effects. When you run ground effects, they are playing games with 10mm ground clearance, so they do want very much air at all under the car.

EVERYONE else thinks air under the car creates drag.

[aerohead]

Originally Posted by KamperBob

Half wake sounds pragmatic.

yeah,50% would work pretty well in the real world.
W.A.Mair (the boat-tail man ) recommended truncating at about 52% aft-body.
Some cars which are at or near 50% are:
*1937 Tatra 87
*1938 Schlor car
*1948 Tucker Torpedo
*1964 Ford GT 40
*1965 Ford Mk IV
*1968 Ferrari 330 P4
*1981 VW flow body
*1982 Western Washington Univ. Viking-V
*1984 Chevy Citation IV
*1992 EV-1 LSR (Ft.Stockton,Texas)
*1994 Bugatti EB110
*2006 AeroCivic
*2009 VW 1-liter car
*2009 Koenigsegg CCXR
*2009 Lamborghini Sesto Elemento
*2011 Bugatti Veyron 16.4 Super Sport
*2010 Lamborghini Murcielago

[aerohead]

Originally Posted by duffremle

I've kind of wondered about the feasibility of a windsock style boattail. Something along the lines of a sea anchor, but fitted to the rear end of the car with just enough of an opening to fill it with air at speed.

There's a fella in Lubbock, Texas who's been 'inventing such a thing for 18-wheelers.
Texas Tech University did model wind tunnel experiments for him.The concept is fairly mature now.