State-of-the-art Japanese fighters with western engines

[spicmart]

What about Kawanishi Ki-61/ Nakajima Ki-84 hypothetically equipped with Griffon/Jumo 213/DB 603 engines?
Would they have been the equal of any ETO top tier fighter designs?

 

[tomo pauk]

Probably a bit slower than the Fw 190D-9, but with the tighter turns possible.
With 2-stage supercharged engine versions, probably as fast as Merlin Mustang, or at least as the P-47D.

 

[spicmart]

Probably a bit slower than the Fw 190D-9, but with the tighter turns possible.
With 2-stage supercharged engine versions, probably as fast as Merlin Mustang, or at least as the P-47D.

Both Ki-61 and Ki-84 have greater wet area than the Dora. The Ki-61 had the same wing profile as that of the Me 109, not exactly a low drag airfoil.
Don't know about the Ki-84's. Weight of both would be about comparable to a Griffon Spitfire
Having bigger wings (20 and 21 m^2 respectively) they should perform a tad better than the Dora at altitude with different Jumo 213 versions.. With a Griffon they should be as good as the Spitfire XIV, maybe a bit better down low and a bit less up high as the Spit has 22.5 m^2 (20 Series have 23.5 m^2) wings.

If you gave them annular/drum radiators Dora-style would they be more than or just as aerodynamic as the XIV?
When the Ki-61 kept its underslung radiator it would be very similar to the Italian Series 5 fighters.
A Mustang style rad would give it a plus thrust-wise and would compensate for the wing profile.

The Ki-100 was said to have been comparable dive characteristics to the Mustang which I highly doubt. It's aerodynamics and weight were just not up to par.