I think the G force calculation would be hard to do and not much use due to various inaccuracies. My Wea GPS is rather poor, turns have the shapes of hexagons instead of circles, speed suddenly varies up and down by 100mph in a second and it regularly shows the model doing circuits and flypasts tens of yards behind the pits! So my experience of the Wea GPS data is that it is totally unreliable for doing any precise work. On top of that you have the general GPS problem that height data is much less accurate than lat/long data, so using it to calculate G in a loop will be poor even if your GPS unit is working well.

I carry an Eagle tree low G sensor in my jets, in stand alone mode it records and displays the highest G level encountered in the flight, so it’s not as good as G per each manoeuvre but at least I get an idea of the maximum stress being put on the aircraft. http://www.eagletreesystems.com/Stan...standalone.htm