Does this kind of F4U3 with a speed approaching 800 km/h really exist? Or "myth."

[Steele]

The data appears in the 14th minute of this video，【活塞飞机性能研究（一）】疾风与紫电篇_哔哩哔哩_bilibili

 

[mjfur]

It was Experimental, but yes it did exist.

F4U CORSAIR - The Bent Wing Bird plane site / XF4U-3 Corsair

The F4U-3 was to be a high speed, high altitude version of the Corsair. Plans were made for three proto- types to be converted from existing airframes.

www.jdsf4u.be

F4U CORSAIR - The Bent Wing Bird plane site / XF4U-3B Corsair

Developmental problems persisted with the Pratt & Whitney XR-2800-16C engine, the F4U-1A,BuNo. 49664, was fitted with a R-2800-14W engine and became the XF4U-3B

www.jdsf4u.be

F4U CORSAIR - The Bent Wing Bird plane site / XF4U-3C Corsair

F4U-1, BuNo. 02157, was the third aircraft converted to the XF4U-3C proto type based upon the XF4U-3 standards.

www.jdsf4u.be

F4U CORSAIR - The Bent Wing Bird plane site / Photos XF4U-3A Vought

The first XF4U-3 prototype was called the XF4U-3A, and it was converted from a F4U-1A, BuNo. 17516

www.jdsf4u.be

F4U CORSAIR - The Bent Wing Bird plane site / Photos XF4U-3B Vought

The F4U-1A,BuNo. 49664, was fitted with a Pratt & Whitney R-2800-14W powerplant with methanol power boost and the turbo charger installed, it became the XF4U-3B

www.jdsf4u.be