From some testing this week I have found that the amount of weight in the tip of these weights really changes the engagement rpm. The weights design really tucks them under, so the the more weight you run in the tip the higher and more erratic your engagement will be.
The first setup i had was 85.8 grams with 8.5 in the tip and 6.8 in the middle, with black polaris spring. It engaged anywhere from 41-4500. I was also under reving a bit. So I dropped 2.2 grams off the tip and changed to a cat gold spring. Engagement dropped to 3750 which was what I was aming for. I also changed the helix to deal with some poor back shift issues, went from a 40 down to a 36 and back shift was much better but now I was over reving. So I added the 2.2 grams back to the tip and my engagement jumped back up to 4000.