Nigd3
This isn't something you wanna try without some practice! You may end up destroying yourself or the aircraft or both.
Get the G metre calibrated on the ground. If you don't have experience with high g forces in an aircraft, don't do this.
I routinely pulled +7 (and more) and -3.5g doing post maintenance and acceptance test flying when I was in the airforce. It was mandatory on full-card test flights. You definitely have to get used to this.
If you're hell bent on doing this, go to a club with aerobatic instruction and get yourself worked up by a professional to withstand G.
Good luck 'n happy contrails
k-o-t-s