Spitfire IX at 27,000 feet. IL-2 Sturmovik: Battle of Stalingrad
High altitude is where its at. BUT Im finding that to do it successfully, requires knowledge of the engine management. For example, you cannot operate the FW190D-9 Dora above 7000m without power problems, unless you firstly adjust the thermostat to 100% and once you do you are good to zoom up to 9000m +.
Same same with the Spitfire IX. Affter mucking around for hours, I have settled on 100% power, radiator manual mode and full open. That has enabled me to fly the Spit 27000 feet at full power, for the duration of the dogfight! If you dont full open the radiator you can last about 3 minutes at 80% power before you experience power problems. AND Once the Spit IX is producing that kind of power, it is fast enough to defeat the Bodenplatte axis fighters in this vid.