Thanks for your responses, all.I'm just wondering what speed I should be trying to keep the 39Q at when I'm turning - my parameters would be 50% fuel load, no wing guns, and probably at 2500ft altitude (rarely get above 10K in the bird, and most fights are probably anywhere from 0 to 5,000 ft). I hesitated to refer to it as a velocity since I thought velocity always implied a directional component and the direction is constantly changing when you are turning. I didn't realize how involved the calculations are- I have no idea what the Airacobra wing's coefficient of maximum lift is. I do like the simplicity 2.44 times stall speed-- where did that come from? I think the 39Q stalls between 90-100 mph, so using 95mph gives me about 230mph - does that sound reasonable? I've started to read Badboy's paper and am very impressed. Greziz - if you are turning at the edge of a stall, I don't think you are getting around a circle as fast as you could be if you instead kept it at corner velocity. At least that's my understanding.
I think we can assume the OP meant the corner speed in AH. I'm not criticizing your more accurate method but in the absence of known lift limits the 6 G limit is convenient.I don't believe you can exceed a 6 G load limit for the P-39Q. I believe you're correct that some aircraft are penalized by the 6 G limit assuming the pilot could handle the higher G.
The 6G limit just drops the manuever point several mph