I dont believe in "equivilency" charts at all. 17.5 (blinky) is WAY faster than 27t ever was. Part of that is addition of 8.4 lipo. That is equal to running a 7 cell nicd/nimh from back in the day. So with the battery factored in in its more like a 1.5 turn drop. IE 27T brushed=25.5 brushless, and 19T Brushed = 17.5 brushless. At least thats the way it feals on the track. And dont forget to add the fact that you dont loose power durring a run due to the way high mah and c ratings that batteries now offer. And for those thaf miss the "old brushed days" you must have only bashed where it didnt matter about new brushes or clean comms. I remember having multiple springs and compound brushes for fixed timing classes all cut with different faces to getnthe most out power out of them. And a cutting the comm every few races. I absolutely love brushless and lipo and would never go back.