Enter a normal 45 deg AoB steep turn.
Increase angle of bank to 60 deg, increase power to full throttle and then increase bank and back pressure further until the aircraft is turning on the buffet nibble in level flight. Use sufficient rudder to keep the ball centered; if the ac starts to descend then reduce bank slightly whilst maintaining the buffet nibble.
For a max rate possible turn, once the max level turn has been achieved, increase the bank yet further until a descent has started. Then keep increasing bank and back pressure until you're turning with full power, on the buffet nibble and at the maximum permitted 'g' for your aeroplane. Not easy - but it'll turn like crazy!
Do NOT do any of the above without first having first been taught how to do so safely. It is very demanding and most civilian GA pilots will not have been trained to fly their ac at the limits of its performance. When we students used to do this in the Folland Gnat, we had to trim to +5g and then squeeze to +6g on the buffet nibble whilst looking backwards over our shoulders to see how many fingers the QFI was holding up!