I'd be utterly astonished if the Cessna 152 had a +6g normal limit. I last flew the Cessna 150 about 40 years ago and recall that the ultimate load limit (the point at which it fell apart) was around that value. 6.6 g, was it?
Flying at CLmax (buffet nibble), full power and at the normal G limit will give the max turn rate / min turn radius in a light aeroplane; anything else will reduce performance. But trying to sustain more than about +4 g without training and a g-suit will probably induce g-loc and possible death.