Although there is a general agreement in this thread that performance trumps manoeuvrability, defeating more manoeuvrable fighters could be difficult. I found some (translated) comments from Johannes Steinhoff at
Johannes Steinhoff – First Aero Squadron Foundation ™ on fighting against Yak-9s...
"...
Me 262?"
The Me-262 was intended to either be an interceptor or a "ground attack / bomber" aircraft, from what I've heard, so it may not be the best example to use in this case.
La-7 was faster than anything Japanese had, bar the full-spec Ki-84. It was also a bit weakly armed for the standards of the day, and was short ranged - the 'no free lunch' rule applies as ever.
I suppose that every strength in an aircraft's design demands the sacrifice of another.
G.56 was a prototype, powered by a foreign engine. P.119 was also a prototype. Same as the Ki-83 that was still in the prototype stage, that supposedly was good for 438-470 mph (I'm not going to put my had in the fire to prove any of these speed figures, FWIW).
From what I've read on the Ki-83, the general consensus is that the prototype Ki-83, in good condition, was agile around 650kph in Japanese tests, and exceeded that number to reach a speed of 686kph, if I remember correctly—and there's yet another ((100x + 80) + ((6X_n + 2) mod 25))* speed, if is a real figure, that is—and 704kph in later tests, though documentation, is, if not destroyed, difficult to find, apparently, for both the Japanese and American tests, the latter was where the >750kph figure was supposedly achieved, maybe. Seriously, I've even seen 580kph for the aircraft of other nations, like some Spitfire variant for instance, never mind Japanese aircraft.
The P.119 seems superior to the Ki-61-ii prototype, even with the latter weighing less and featuring a similarly powerful but liquid-cooled (and foreign) engine. The former even appears to be the larger aircraft based on the specifications I have at hand, although the novel engine layout might have given it an advantage, I'm not sure. The propeller? This comparison paints a brighter picture of Italy's wartime aviation industry, unless I'm wrong, which I could very well be.
Care to elaborate the G.55 tidbit from there?
I've seen 650kph listed as the maximum speed for the G.55 in certain place(s) on the internet.
The Soviet aircraft were usually closer in size to a 109 than to anything the Japanese were using.
Actual size (drag) of the aircraft is more important than weight for speed. Weight starts becoming more important than size when figuring climb.
If you want a 220-230sq ft wing you pay for it in drag vs 175-190sq ft wings.
Information on the Fiat G.55/56/59 can found or guessed at using the post war foreign sales examples. The G.55A was a post war G.55 using left-over DB 605 engines. The later G-59 used commercial Merlin T-24 engines. The T-24 engines had a lower FTH than the DB 605s but they were supposed to be good for 368mph at about 20,000ft (sources differ) but that is with four 20mm Hispano guns sticking out of the wings and possible bomb and rocket rocket racks (1950s style). They got the two seat G.59-4b trainer up to 380mph.
The Ki-44 is an example of a small frontline Japanese fighter, though the engine of the later variant was weaker than, say, the La-7's, by a few hundred hp. It was rather tall, and had roughly similar wing-loading to the La-7 despite its lower wing area, it seems.
Sure, it wasn't a disastrous strategic defeat, but neither was khalkin Gol. Unless you believe the future of Imperial japan lay in Sibiria. To add a bit of context on that battle, it was fought by a somewhat rogue fraction of the Japanese army without the full support of the IJN. I don't think it probable that full support could have resulted in a victory, but I belong in the camp that think that not starting a full scale war with the Soviet Union was one of the better strategic decisions made by the Japanese. Yes, it could (maybe) have resulted in the collapse of the USSR cought in a two front war, but the Japanese cold not, and probably did not, trust Hitler. Or that he would knock out France in 1940, a true strategic disaster for western powers.
German soldiers seemed to be able to achieve more favorable kill ratios throughout much of the war, maybe less so against the forces of the Western Allies, in contrast to Japanese soldiers, and while there have been various reasons considered for the higher mortality rates of the Japanese soldier, the most damning reason is poor equipment and logistics, the former reliant on the latter, and both reduce the credibility of Japan as a major industrial power for the period. Late-war Japanese forces, from what I can remember, displayed competence against overwhelming Soviet forces, especially when the Soviets attempted naval invasions, but by that time Japan's already inferior forces were in freefall. I've heard that that the Japanese army of the 1930s would have potentially struggled against even the contemporary Polish army, the same nation that was overrun by German forces in a few months. It is a highly speculative scenario that I would follow your advice and discuss further in the "What If" sub-forum, if the inherent absurdities could be tolerated.
I don't agree that rocketry and jet technology were in any way decisive in ww2, even then it seem the USA was not in the forefront. It was still a great power. They became vey important after, and could have during if the war was prolonged. But that war we discuss in the what ifs.
We can come up with specialities, and argue that this or that speciality was telling while others were merely second rate power adaptions of existing technology. We can also focus on prototypes which, whether the publicised data were correct or not, would never have worked in a fighting environment. But like jet power, that is concentrating on the spectacular rather than the in practical terms significant.
I'll grant you that the axis did just that. Apart from the miscalculations as to the speed with which they could finish their campaigns, and the lack of resilience of decadent soft regimes, they believed they could also make up for numerical inferiority with general technological superiority. Instead they had some great achivements, a lot of average ones and their share of the truly dismal. I don't recon japan was worse of than Italy, though Germany overall achieved more. In view of their industrial base they should be expected to.
The United States had the world's largest economy, was home of numerous inventions, including powered flight itself, and was one of the victorious powers in WWI, not to mention its growing cultural influence on the world stage. In fact, the US had been ordering hundreds, if not thousands, of jets like the F-80 for the war over Japan. Ki-84s (likely some newer, slower(?) model), A7Ms, Ki-102s, and maybe a few Kikka and J8Ms (all in various states of maintenance), if they had managed to survive against the already numerous Allied props and superprops, against hundreds of jets. A slaughter. The future prospects of the Japanese Empire were dire, even if somehow, their conquest of China was accepted. An increasingly outdated military against a potential Soviet threat, even in the wake of a Brest-Litovsk-esque treaty (total German victory was almost impossible), and an increasingly hostile American and Commonwealth once they come to their senses. I haven't even touched upon radar or nuclear weapons. Granted further discussion can only continue in a different thread in the appropriate section.
I will admit that Japanese military technology was on par with, if not superior in some areas, colonial and Pacific forces in Asia—though this advantage primarily arose from Allied arrogance and negligence, and was largely superior to the foreign-dependent militaries of Asia. Japan also appeared to be catching up to, and exceeding Italian aviation technology at times, as the latter generally utilised German engines in achieving higher performance. However, Italy still appears to have had a stronger scientific tradition than Japan. Enrico Fermi was an Italian, and a professor in Rome at that.
Pertinent to this thread may be the 'butterfly flaps' of Nakajima. It's not rocket science, but the successful installment in combat aircraft gave one edge to aircraft without paying in full the usual speed penalty for greater manouverability. I'm not saying that the Ki-84 was a superplane exceeding everything the allies had, but in good finish it was a worthy opponent. The usually poor finish was a result of the war going badly for a long time now, not any inherent weakness apart from not being big enough. And some very bad decisions, like fighting the worlds largest industrial power and the most populous at the same time. And the Commonwealth now they were at it.
It's still merely a variant of a fowler flap, and isn't counted as a distinct flap type in its own right.
* Unsure if the random generator here is good, but it exists only to express my feelings on the matter.