Originally Posted by
PDR1
Interestingly in his memoirs ("Fly and Deliver" - memoirs of an ATA pilot) Hugh Bergel .... also expressed frustration about the way that all British aircraft with supercharged engines had automatic boost control - a system which ensured that when you set (say) +6lbs of boost it stayed at +6lbs at all altitudes and throttle settings, whereas the boost control of american aircraft just controlled the wastegate and needed constant monitoring/adjustment with changes in altitude or throttle setting which (he suggests) would have been a major pain in combat and was suspected to be the cause of some engine reliability shortfalls.
I think that would be the difference between mechanically-driven superchargers and turbo-superchargers - the "wastegate" was in effect a turbine bypass, which was to be found on the latter. However not all supercharged US aeroengines were turbo-supercharged and I wonder what Hugh Bergel made of them.
As I remember from reading his book* many years ago, Bergel was pretty forthright about the aeroplanes he had flown - it was he who claimed that the vibration of the P39 Airacobra caused it to become a blur, even when you were inside it.
*ETA it was "Flying Wartime Aircraft" rather than "Fly and Deliver" I now remember!