Mr. Disinformation (Should I call you Baghdad Bob??) you might want to consider that the Yak9 is 2000+ lbs lighter, with just as many horsepower, and a more streamlined frame. Definitely going to accelerate better. Also, 2000+lbs lighter it's going to turn a hell of a lot better as well.
That 2000+ lbs is only for the P-39D. The 9100lb P-39N weighed 50% more than the Yak9T, at 6500lbs.
The P-39Q weighed 5645 pounds empty, 7600 pounds normal loaded, 8300 pounds maximum loaded. So even on normal conditions it was over 1000 lbs heavier than the max weight of a yak9T.
Also, for your P-39Q numbers:
P-39Q-5-BE was rated at a max speed of 330mph at 5000ft, 357 at 10,000ft, and 375mph at 15,000 feet. So the speed is pretty much identical to the speed curve you posted up to 13,500ft, and only between 13.5k and 15k does the P-39 power curve get higher, then it drops. So maybe I wasn't right by saying faster than all P-39s. It's faster than all but the Qs, and even then it's just as fast up until its power curve drops off. And, let's face it, nobody but nobody is going to fly it above 10k in this game.
Climb to 5000 feet in 2.0 minutes. Climb to 20,000 feet in 8.5 minutes. That's 2500fpm at best, below 5000 feet, and it gets worse above that. No way is it out-climbing the yak.
So before you start b****ing at me and spewing BS in my thread, get your own numbers straight before trying to tear my head off.
Like I said, between the two, the Yak9 is probably better in many categories, including turn and cannon, but that was by no means a negative comment to the addition of this craft in the game. That was a direct-frakking response to somebody's direct question.