Have a little experience of turbochargers but ones that (mostly) stay on the ground. I understand the principals of supercharging but one thing confuses me. As I climb in my Ki-84 the power drops off, especially above 7k. As I hit something like 10,400 feet I get a sudden burst of climb rate which I'm infering matchies a bulge of power again. Since the atmosphere presumably thins at a constant rate, how come there's a bulge of power there, is it to do with coincidental gearing in the supercharger? Also WEP makes no difference at certain alts but this also appears to not be linear. What's going on?