Hi Grünherz,
>But still I'm really surprised a standard production service mid 1943 G5/6 with only standard GM1 and some polishing could fly so high.
Usually, the service ceiling is considered to be reached when the climb rate drops to 0.5 m/s. For a 3000 kg aircraft, that would mean you'd have just 25 HP left for lifting the aircraft. GM-1 injection gave 350 HP at any altitude, so climb rate would be up to a very respectable 7 m/s again, making it possible to climb higher rather quickly.
Additionally, GM-1 also gave considerable extra exhaust thrust as the mass flow through the engine was increased. At the high true air speeds at great altitude, this helped a lot, too.
Another effect was that the power increase was possible without increasing the engine speed as the extra oxygen was provided by the N2O and didn't have to be pumped into the engine by the supercharger. That meant that the propeller could run at a lower tip speed, which equalled a lower Mach number and a better efficiency.
From the Gustav onwards, the N2O also was stored as a liquid and evaporated in the intake air, providing an additional charge cooling effect that provided yet another bit of extra power.
Compared to a turbo-supercharger, N2O was a very light and powerful system. The downside of course was that it was available only for a rather short time - the Me 109G-1 for example consumed the N2O at 0.1 kg/s, so it got about 17 min of operation from the 104 kg of N2O carried in the standard 85 L pressure vessel.
Regards,
Henning (HoHun)
