Attached is the spread sheet that was one I originally used for determining the best way to accomplish a cross country race turn over a pylon,  The formulae are from "Aeronautics for Naval Aviators", a very useful reference.  It does calcs for bank angles over 60 degrees.  I included time and distance numbers for various speeds and bank angles to determine the best configuration for an efficient turn.  I added some calculations for considering a power out descending turn back to the airport.  I have still been unable to find performance formulae for descending turns but then I haven't tried very hard.