No joke: 248mph Hurricane dh5-20, 230mph Spit... what on earth is going on??

[NZtyphoon]

Spitfire performance comparisons fixed pitch 2 blade v 2 speed v constant speed props:




NB: The wooden ROTOL CSP is almost the same as the type fitted to the Spitfire IIa (N3171 was part of a batch of Spitfire Is in the N3--- series fitted with Rotol CSP and UHF radios and used operationally Feb - May 1940 by 54 and 66 Sqns)





In general the speed differences between various prop types seem to be reasonably well modeled for CLOD.