Sorry ckuang, I dont have a number for you. On the T we set the mainsail so the telltales streamed and went from there. Often that was with the traveller out 10cm and some sheet. More than one armlength of sheet released from that setting was more than what we wanted to try. I have seen some of the alu wingmasts really bend forward with the sheet released completely but that is neither fast nor safe. I dont have any advice but watching the mastbend and dont do anything scary.

I dont have a F16 yet. I have sailed tornados until last fall, then we began building some F16s. We hoped to launch this summer, but alas. Now we aim for next summer. We have a building blog here: http://woodastic.blogspot.com/
I have been hanging around the F16 guys for a very long time, but have not taken the jump until now. Our masts will be Tornado sections cut down to size.