I never pass out with Partial suspension (Any advice?)

[b12ruinedme]

I've tried passing out using partial suspension in various positions with a rope and a slip knot and never pass out. I sit down really hard and sometimes reach dizziness, when I standup my legs sometimes shake, but that's it. Never reach the warm feeling in my face and vision doesn't get blurry. I often have to get up after 30 sec or so because i can't hold my breath any longer. Why does it seem so easy for some people who pass out in 10 seconds?! Should I use a bed sheet instead? Will i pass out more easily with something soft. Are my cartoids so deep it just won't work for me, i've always had a strong neck...

Any tips/advice is greatly appreciated!