I had a Windows XP computer some years ago and had the stock 4.07 installed - I had great offline dogfights with the original AI, albeit having to put up with some of the original AI characteristics. The combats were such that many times the outcome was uncertain - I'm not looking to club baby seals, I want a good balanced fight with the aircraft reasonably within historic fact, and I expect to get shot down myself sometimes, the best aces did.
I then purchased a new computer with Win7 installed; it was loaded for gaming purposes and was in every way superior to my antique Win XP. However, it dawned on me after some time flying that while the graphics were definitely superior, the flyable aircraft I used were all noticeably diminished in performance, especially speed which is pretty much the foundation of all maneuvers.
I tried all sorts of remedies to overcome this, but to no avail. I inquired on various forums, and no one reported having encountered this problem. It effected all flight simms I flew, and all Il-2 1946 mods I subsequently loaded. HSFX helped a bit with their 'Expert mode' modified flight models for some of the aircraft I fly, particularly the Fw 190 and 109's. My computer is a duo core, so pretty long in the tooth, but perhaps you have a similar processor.
Also, Il-2 1946 modified flight models beginning with 411 greatly boosted the Spitfires performance, and significantly diminished the 190 and 109's performance, especially with turning - not saying it's wrong, but it will come as a shock if you were flying the earlier loads.
Finally, there is the lovely Il-2 "
realistic mode" [thanks guys!] which I say yes and no. Yes, aircraft varied and wartime events took their toll, especially with the confusion and disruptions of Germany towards the war end. But most pilots flew one dedicated aircraft until lost in combat, or the to end of the war, supported by a highly trained and passionate ground crew chief working closely with his pilot to keep the aircraft in top condition. In Il-2 1946, EVERY FLIGHT SESSION gives different performance, and this often severely impacts the combat experience you have. I can fight spitfires straight up most times, but when my aircraft has diminished engine performance, diminished roll rate, having odd or out of balance control input responses, aileron sticking etc, and my opponent is rocket powered, we're no longer in the realm of reality. This caused me alot of frustration for a time, but I learned to use one of the other mod loads until I find one that is not so out of wack. I sometimes add greater fuel load to the opponent aircraft to bring it's performance back closer to reality. I do speed runs with the opponent chasing me and see if I have the proper advantage [Il-2 compare], but even with this method if the overamping of the 'reality mode' misfire is too great to overcome, you just move on the another game.
As for 109's and 190's vs Spits, as an example of how it's done, I recommend you view Leo 'Black 13' here:
He flys 109's equally as masterfully, but a well flown 190 is devastating to any spit, any time, if you use the aircraft's strengths. Yes, a spit can turn horizontally, but were not racing Le Mons here are we? You beat him with your all around control harmony, topped off by those deadly ailerons, and of course, with intelligent and quick thinking.
Good hunting, hope this helps somewhat.
p3