No one said that the overall drag doesn't affect climbrate,
Fair enough, but I took exception to the way you seemed to brush off the importance of drag in climb rate. I will let it go and move on to the important stuff...
Rene J. Francillon, take him or leave him, says in regards to rate of climb:
Ki-61-I-Otsu (-b) gonna get 5:30" for 5000m
and Ki-61-I-KAI-Tei (-c) 7:00"
The Ki-61s had a number of configurations, armors, weights, and fuel tankages inside any number of "variant names" -- they would make changes without changing the designation -- so that's the best and worst case right there. 5:30 minutes is 2982fpm average. 7 minutes is average of 2300 fpm. The Ki-61-II was listed as getting to 5000m in 5 minutes flat.
Please see this very interesting post on the ubi forums:
http://forums.ubi.com/eve/forums/a/tpc/f/23110283/m/2101024949?r=1331061059#1331061059He's a bit of an expert in other forums. He is using first-hand original Japanese documents, official japanese handling manual info, there... He "hangs out" (for lack of better term) on forums with some other experts as well.
He shows how the prototype Ki-61 made 5000m in 5:00, the production Otsu in 5:30, the production Tei in 7:00, and the production Ki-61-II Tei in 6:00.
He includes a list of resources on Ki-61 and Ki-100s that has probably more than 50 items on it (and that's his "short" list).
I think the Ki-100 is very similar in climb rate to Ki-61s. I think OUR Ki-61 is a bit of a dog and perhaps not the best (for example, the flight tests showing it turns as well as an FM2 whereas in-game the FM-2 will out turn it easily). Assuming a Ki-61 flight model re-visit, I think a Ki-100 wouldn't be noticably better in any category, excepting the second supercharger gear it has to power it at higher alts.