Thanks for all your work here, Marv. You were key to my decision to get the Sprint 2. I must have read this entire thread 4 or 5 times before I pulled the trigger. I've done several of your mods successfully, with just a few minor changes here or there.
I had a Traxxas Stampede with a Castle 7700kv motor in it that I was seriously wanting to down-grade, so as soon as I got the Sprint, I pulled the power system and swapped it with my Stampede.
I hit 65 mph last night on a 2s pack on its first run.
The ESC hit thermal shutdown after 6 minutes of speed runs...it still works on the bench, but it sure does stink!!
I'll have to take my GoPro out and get some video.