"so... how much altitude did that burn?  From 80 kias, about 700 feet. The rollin is a little slow as there is a need to build a little speed for the turn. A nose-high turn here would be very close to stall.  From 100 kias, about 500 feet"

Bob,

These numbers sound pretty good.  I did some very similar tests in a Grumman Tr-2 many years ago.  I don't remember the exact results but I do remember concluding that I wouldn't want to attempt a teardrop turn back to the runway at less than 1000' AGL; assuming it would even make it back to the runway.  The Tr-2 glided a lot like a truck with both doors open.  But, as they say in the ads, your mileage may vary.

Tom Gourley