Why still no dive acceleration difference?

[BlackBerry]

Let's discuss this record.

(C)

(1) 10000 fett to 3000 feet, starting at 250 m.p.h., diving at angle of 65 degree with constant throttle setting. The FW-190 pulled away rapidly at the beginning but the P-47 passed it at 3000 ft with a much greater speed and had a decidedly better angle of pull out.

Jtd's explanation:

The differences in initial acceleration between individual planes is there, if you fly them properly. Some of the acceleration differences you see as simple statements "this one is better" has a lot to do with engine management. If say an Fw 190 and a P-47 cruise side by side and then go into a full power dive, the guy in the 190 slams the throttle forward and off he goes, while the guy in the P-47 adjusts mixture, then rpm and then the throttle and then starts to accelerate. Gives the 190 a two second head start. But even without considering this, if you compare a 190A-4FR with a P-47D-22 at medium altitude in 4.11, you'll be getting something similar to the test you quoted.

It sound reasonable, in a real world combat, the engine management can't be neglected, but this is a "test" to determine dive accelaration so P47 should prepare for diving: at first setting rich-mixture, rpm/pitch to 3000rpm, throttle to 40% so that actual engine rpm is 2000 or so(although pitch is fine), criusing side by side with fw190 @250mph IAS. Next step for P47 is just slam the throttle forward and dive.

BTW, I am doubt fw190A4 could PULL AWAY RAPIDLY from P47d at initial dive in 4.11m.

My GUESS about that historical test:

When diving from 250mph to 380 mph or so, the speed of tip of P47's airscrew firstly reached 0.8 Mach than fw190's due to its greater rotating speed. When P47's reached 0.8 Mach and suffered from obvious airscrew efficience drop while 190's remained at BELOW 0.8 Mach, 190 had more thrust and outdove P47 rapidly.

But 380mph IAS(just my estimate) is the turning point, where P47's tip breaks sound barrier, and the drag coefficient of airscrew tip DECREASES, P47's efficiency INCREASES as we known that the majority of airscrew thrust is from tip section of propeller. From 380mph to 450mph, it was 190's turn to suffer from efficiency drop due to it's 0.8-1.0 Mach tip speed, P47 began to catch up with 190, and the P47's hugh weight advantage boosted its taking over because the higher speed, the more important role of weight. Therefore P47's diving accelarartion became astonishing-------quickly catched up fw190 200yard ahead, and passed 190 with MUCH GREATER SPEED like "thunderbolt".