[Juha]

Hello Harri
Quote: “I took values from the "Lentäjän Näkökulma IV" and got 423,66km/h at 5000m for 8600kg. Assuming e=0,8, n=80% and 120kp exhaust thrust (Do 17Z seem to have ejector outlets). So while not exactly accurate, the ballpark appears to be correct.”
You are too modest, your result is well inside normal variation between individual a/c.

I thought that result of 500 lb weight increase should be fairy insignificant and even if I remembered Do 17Z tests I tried to look some fighter results and got the idea to look Spit Vc, which was some 400 lb heavier than Vb when armed with 4 Hispano cannon but found out that the max speed of the Vc tested was between the speeds of the first 2 Vbs I checked. So I thought that I must look something more substantial weight increase and checked Spit IX, 900 lb heavier and 30 mph faster at was that 2000 ft. Now I knew that that was more complicated because of different nose contours and because of bigger (and dragger) radiator in IX, I found out power curve for Merlin 61 and was looking one for Merlin 45 when I checked this thread and found out Kurfürst’s message and saw that there was no need for more effort.

Quote: “Do 17Z seem to have ejector outlets”
Most seemed to have but not all, at least DN-54 and one other, was that DN-64, anyway one Z-5, ex Z-3 a/c, seemed to have older system, ie 2 exhaust pipes which came through upper part of NACA ring.

Juha