Quote:
Originally Posted by JtD
Regarding the speed figures from ww2aircraftperformance. You'll see the effect of the engine gap. This was not sealed in real life. In performance calculations it was assumed sealed, because the model wasn't exact enough. So tests with gap sealed as well as Fw performance calculation show higher speeds than were attainable with the real D-9. So for reasonable real life performance, take the green line (Fw Flugmechanik, 15.12.44), and subtract 10-15 km/h for the effect of the engine gap.
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If you are basing your La7 FM on the "эталон"(prototype) La7, why not use the FW's figures with the sealed engine gap?
The real life La7s that saw combat would surely be noticeably slower than the prototype?
So if you choose top stats for FMs that green line would be a good model for the 44 Dora, and the C3 line would be a good model for D9 45.
In reality, the Il2 compare figure @2000m is 625km/h and FW data shows at least 650km/h. Even the captured D9 (sealed gap) shows 645km/h.
And finally, even the captured 190 with the gap not sealed shows 630km/h.
So across the board FW190D9 MW50 figures are (often way)lower than it was in reality, while La7s(for example) is represented by the prototype model (so it was in the perfect shape for those trials when they got 680km/h) or even slightly better (Il2 Compare shows 682km/h). Many Russian sources(not just Wikipedia) state La7s top speed was 661km/h. So why 682km/h? That's even more than the prototype's figure!
Is it just me of this does indeed look biased?
Quote:
Originally Posted by JtD
3250 rpm were allowed for 30 mins max., unless the engine exceeded temperature limits.
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If 3250 was allowed for 30 min max that kinda gives a ballpark estimate of the engine endurance, doesn't it? Why would they allow it for 30 min if engine overheated in under 2min and died in 5 even with the open radiator while going ~600 km/h? That doesn't make any sense.
And what about the 1944 vs 1945 issue - why the 1944 D9MW50 is in 1945 plane set but 1945 La7(3 cannon version) is in 1944?