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We'll have to disagree, Juha.
I don't think it was a world beater, but it certainly was better than a lot of other planes out there with similar power. Other ones that come to mind with similar power is the A6M5, the F4F, some of the Reggiannes, a Bloch or two, the P-35, P-36, etc. In that crowd the J-22 is near the top at low altitudes. With a 2-stage it might have held its own a bit higher.
The Germans experimented with a radial on the Bf 109 airframe. I wonder how the performacne of that plane compared? I've seen the pics of the radial Bf 109, but have never seen a performance summary for it.
The solution to top WWII fighter performance was more power and higher ceilings but, with the installed power it had, the J-22 was pretty good when compared with similarly-powered opposition.
Then, like with all slightly overmatched planes, it would come down to the pilots.
And if those planes you mention get fown to 10,000 feet, they still might get surprised.
It seems well documented. Unfortunately a web site with over a 1/2 dozen pages of very good information on the J 22 seems to have disappeared from the web (or Google fu is very weak).
The plane was lightly built however and very well streamlined. ( I believe the normal G loading was 6.5? with a 50% safety factor?) It had several more years of aerodynamic knowledge to help it over the Ki 43.
It may have better use of exhaust thrust although still far from ideal.
I tried using the Internet Archive and found Home which may be the web site. It certainly has some information.It seems well documented. Unfortunately a web site with over a 1/2 dozen pages of very good information on the J 22 seems to have disappeared from the web (or Google fu is very weak).
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