Why still no dive acceleration difference?

[MadBlaster]

you miss the point.

What a wide 3 blade may lose in "thrust" vector efficiency from more drag , it may gain in 'weight" vector efficiency when "thrust" vector efficiency is at zero in a dive and high TAS. The wider blade means higher tip speed from ram air verses thinner 3 blade. This means greater torque to overcome internal friction from the engine. The pilot can reduce internal friction by lowering manifold pressure, but not completely. The engine will still tend to over-speed and this is mitigated by lowering rpms/coarsening blade pitch. So, internal friction of the engine is more easily overcome by the weight vector with the wider blade I speculate.

One way to measure the internal friction of the engine. What was the cranking force required to start the 801? What was the cranking force required to start the r-2800? If two engines are identical, it takes more cranking force to start an engine with a 4 blade wider diameter prop attached than a 3 blade smaller diameter. The engines were not identical. The r-2800 had more cylinders than the 801. If you take off the props, I suspect it takes more cranking force to start the r-2800. I suspect the p47 had more internal friction to overcome than the fw190. This would hamper dive acceleration.