Hello Jaco I'm not sure that I have the complete answer that you are looking for. As for calculating the maximum boost at altitude, it's not necessary, because you will loose boost pressure as you go up. In short the maximum boost pressure on the ground is the same maximum pressure at altitude. For example during takeoff I monitor my manifold pressure gauge to ensure that I limit my maximum boost to 35"hg. I have a manual waste gate that I use to keep the manifold pressure at the desired level. As I climb to altitude, I can eventually completely close the waste gate with no fear that I will over boost the engine. I did find this web site that is about WWII turbosupercharged engines. http://rwebs.net/avhistory/opsman/geturbo/geturbo.htm What I gather from reading it is that at sea level you can reach and exceed your maximum recommend boost pressure(requiring the use of a waste gate). As altitude goes up, the turbo or supercharger looses it's ability to produce as much boost pressure as it did on the ground. At some given point the turbo will reach it's limit and no longer provide enough boosted pressure to keep the engine running with enough power to maintain level flight.
Orma Southfield, MI N110LR Tweety, old enough to drink this year Flying and more flying, to the gathering or bust http://www.kr-2.aviation-mechanics.com/
