Performance data from Kim Blackseth's tests 8/25/07
Indicated airspeed ground temp temp @ 2500' density* altitude true* airspeed fpm - true airspeed climb alt gain climb min climb sec climb min decimal climb fpm climb ratio climb angle deg glide alt descent glide min glide sec glide dec minutes glide fpm glide ratio glide angle deg
60 75 66 3530 63.6 5596.8 1000 4 0 4.00 250.0 0.044668 2.6 1000 1 25 1.42 705.9 7.9 7.2
70 75 66 3530 74.2 6529.6 1000 2 46 2.77 361.4 0.055355 3.2 1000 1 16 1.27 789.5 8.3 6.9
80 75 66 3530 84.8 7462.4 1000 3 19 3.32 301.5 0.040404 2.3 1000 1 10 1.17 857.1 8.7 6.6
90 75 66 3530 95.4 8395.2 1000 3 34 3.57 280.4 0.033397 1.9 1000 1 15 1.25 800.0 10.5 5.4
       
temp on ground at sea level = 75 deg., at 2500' = 75-(3.57*2.5) = 66 deg.
* calculated via http://www.csgnetwork.com/e6bcalc.html 

Pay special attention to the glide ratio versus indicated airspeed.  Note that, at this time, we don't know the accuracy of Kim's airspeed indicator.