Speed graphs for Spitfire and Hurricane

[Sutts]

Originally Posted by camber

I agree Sutts, that mixture feature of the CloD Spit II does not make sense. I can live with it but I would rather it not be there.

I also am concerned about the fact that top speed in the Hurri and Spits is achieved at lower rpm than maximum (2600-2800 vs 3000). I have not seen any historical reference that to get top level speed, you should retard rpm. On the contrary, maximum speed data is given for 3000rpm.

I suspect it is a consequence of the rpm-boost quirk of the CloD engine model. Lowering rpm from 3000 to 2600 in CloD adds some boost (although in reality the boost controller should be keeping boost constant regardless of rpm). More boost = more power = more thrust in the flight model (presumably), so the non-historical boost increase at lowered rpm gives a corresponding non-historical speed increase at lowered rpm.

I'd just like to add that RPM does affect boost in reality. The greater the RPM, the greater the suction in the intake leading to lower intake pressure. With lower RPMs the suction reduces and the pressure rises slightly.

However, if the boost is high enough for the boost cutout mechanism to be in operation then no change in boost should be apparent with a change in RPM since the mechanism will automatically compensate to keep boost at it's maximum permissable value. I believe this is what you are referring to. Just don't want people thinking the whole link between RPM and boost is a quirk in CloD.