I'm not sure it's dead-on 500, it might be 485, but it's certainly closer than most people get. The main trick is to "switch your gears" when they peak, that is, change prop-pitch each time you see your airspeed not increasing anymore.
I'll try to remember to make a track tomorrow (it's a bit late currently) and upload it, it would be good practice for me too and maybe i'll pick up an extra trick or two during the process. Cheers
