Yeah it is very important to keep records.I actually run a new race arm in to make sure everything settles in and send it off for recon and I have them numbered at that time.I've got around 50 I-15 .500 arms at the moment and another 12 .490's so its a excuse to double check the balance and things more so then a necessity to balance new arms like it was before.Although in the past a fresh arm would move a little the first few cycles and the windings would settle in.
Also all of my motors are labeled like Koford 1A,2B,2 C,2 A etc.The number is the style of motor(windowed can,scalloped edges etc etc) and the letter corresponds to the airgap.For instance 1 A is a solid can with .512 gap,this way in my notes I know what arms ran well in what setups.Although some numbers refer to mags like Camen 2 C has koford .500 L radial mags with a .515 gap.
It sounds complicated but my notes will say like Camen 2 C # 22 +.12,Camen 2 C # 23 -.12, The # was the arm and the + and - were from when I used to test on a oval on red.I had a benchmark time I used set by one of my faster motors and the + or - was how far off the combo was.Back then I used to race on a lot of different tracks so the oval really took out the driver variable and track conditions for motor testing and let me concentrate on chassis tuning for the big tracks.
Chances are I may get a Gerding test track that he makes for this as I dont have the banked oval to run on anymore.But my notes from before still helped when i was getting back into things again.
I wasnt the best at keeping records but when I started doing things this way its helped a LOT and there is little room for forgetting a combo.A few quick notes was all it took and if guys wanted to cheat and look at my notes they were clueless as to the setups.Believe me more than a few took a peak at my book while I was testing too.