If you are blacking out you're above corner velocity, which means that he is going to blackout if he turns the same circle at the same (or higher) speed too. So chances are if you getting whacked on a regular basis the guy on your six is doing something besides "riding the edge of the blackout better than you do".
There are three ways that I know of to accomplish this, without being better at not blacking out.
The first way is to do a high yoyo - when you see the bandit pull into a max rate turn where he's going to go into black out, instead of trying to follow his turn in the same plane, you roll towards level and put your nose high and then relax your turn slightly at first and then tighten in as you slow. As you climb and turn you'll slow because of gravity which helps you turn faster than he does without ever blacking out, and once you slow a bit you'll come around just as fast or faster than he can without blacking out, and you'll get smash back when you drop back in on his six - while he's thrown his away.
The second way is to drop your throttle which will slow your aircraft and as you slow you can turn inside his circle without blacking out.
The third is to simply go to lag pursuit (turn wider than your bandit does) and once he relaxes his turn either to try to recover from his blackout or to reacquire you, take advantage of the time to roll in on him again.
Often you'll use some combination of two or more of the three.
What will work best will depend upon the plane you're in vs the plane he's in. In a Corsair, I almost never drop the throttle, since most planes in the game can out accelerate me, and once I'm slower than my enemy, I'm probably not going to get another shot - or maybe not even survive the engagement. In a lighter aircraft that's more responsive to the throttle I'd be more inclined to use the throttle.
There are guys here who can tell you more, and better than I, though. Go see the trainers, they'll help you with it.
