Measuring motor stats w/o a dyno?
Torsion;
I have a Robitronic Dyno which I USED to use to test all of my Motors. Very good information, but my Buddies at the track have been using a much less scientific method with about equal success.
Take the Motor(s) you are considering/tuning and hook them up to a charged 6 cell pack for a few seconds. You will be able to easily hear any differences in Rpm and Accelleration from Motor to Motor. With a little experience, you will be able to tell which Motor is better. and which tuning changes made a difference.
Not very scientific, but it does work!