[aerohead]

When I did the installment on aftbody"quotes" I wanted to give you "all the gory details",spoken from the horses mouth.When I got up to 1963,I included a quote from Walter H. Korff,one of my hero's.although something stuck in my craw for what he was saying.Since that post,I dug a little deeper and found the reference Korff used and while not untrue,if not taken in an EXACT context,it will throw you completely off the globe! -------------------------------------------------The source is Hoerner,it's from 1951,and here's the deal: Given that a car is operated in traffic,goes up and down driveways,and must fit inside a parking garage,one would consider giving it a "resricted- length." For a "restricted-length" vehicle,a chopped-off rear will have a lower drag than a than a radius'd rear.Hoerner recommends that you chop the rear at 50 % of frontal area.--------------------------------------------What Korff said,and I'll repeat the quote"this blunt...aft portion will have no more drag than a full length streamlined body that curves down to the bellypan." I believe what Korff means to say,is that a restricted length body,curving down steeper than the prescribed aerodynamic pathway will tolerate,will have separated flow,so allow it to follow the prescribed pathway until you achieve 50% frontal area,then just chop it off.When he uses the term "streamlined" I believe he is using it in the context of styling,not true aerodynamics.----------------------------------- The fact is,that if a "full length streamlined body" continued out to where it intersected the line of the belly pan,that the vehicle would experience an additional 50% drag deduction.This would be physically impossible to achieve at 50% frontal area chop.