109 e4 performance

[Crumpp]

So basically the French obtained 494 kph at 600m with 2400 rpm and 1.346 ata.

Where do get that? The French NEVER used the German technical atmosphere.

The French were instrumental in forming the ICAO in 1912 and adopting a standard atmospheric model of that organization, the ISA.

The ISA uses 760mm as 1 ATA.

Once more, the 1.28 corresponds to the 1.3 ata rating. There is NO 1.35ata rating cleared for the DB601A according to any documentation I have seen.