Why still no dive acceleration difference?

[BlackBerry]

http://history.nasa.gov/SP-4103/ch8.htm

The NACA's failure to discover and develop jet propulsion should not be allowed to mask its real and significant contributions to American aerial victory in World War II. Though air power was not the sole, [195] or even the most, important ingredient of American victory in the war, it was a key ingredient; without the NACA, American aerial superiority would have been less complete, less early. Every American airplane that fought in the war, every aircraft engine, had been tested and improved in NACA facilities. Most of this cleanup and testing was incremental and anonymous, hard to trace to the NACA, and difficult to evaluate. With military officers, NACA engineers, and aircraft designers and manufacturers all poring over the same test results in an effort to improve the flying qualities of an aircraft, the credit for improvements must be spread widely. Some examples of NACA contributions can be isolated, as when the Committee predicted that the B-32 would fail and recommended that its development be abandoned. In some cases, the prescribed NACA fix for a problem aircraft was rejected by the manufacturer, as when Kelly Johnson of Lockheed ignored the first solution proposed by the NACA for the problems his P-38 was experiencing.45

Two Committee achievements during the war were so obviously useful and noteworthy that the NACA took great pride in citing them. The first investigation undertaken at the new Ames laboratory - icing research - was so useful not only to military bombers operating at high altitudes and through all kinds of weather, but also to commercial operators, that it won for its principal investigator, Lewis A. Rodert, the Collier trophy of 1946. The low-drag wings of the P-51 Mustang, the result of years of NACA research on wing characteristics, became a hallmark of NACA achievement. Though some questioned that these laminar-flow wings (as they were often and incorrectly called) were responsible for the unparalleled performance of the Mustang, most agreed that they were a significant contribution to airfoil development and drag reduction. John Victory was pleased to report in later years that captured German documents revealed an inability by the Germans to account for the superior performance of the Mustang, even after they captured one intact and tested it, because their wind tunnels could not duplicate the low turbulence produced by the NACA.

So German's conclusion is not valid for allied laminar flow 3-blade vs 4-blade comparation. German never used laminar flow airfoil in wings, nor the propellers.

Xf4u-1 test speed is not high, merely 640km/h TAS, we don't know the difference between naca16 and Clark y at high speed, 750km/h,800km/h, etc.

Is that possible for 4-blade laminar type prop provides more power loading than 3-blade of traditional airfoil while keep the drag level remain same?