Sega Sound Help

I learned how to do it a while back doing uvula oscillation and middle zipper but I want to do it on the side of my mouth. To me it sounds more powerful and cleaner when other beatboxers do it. I learned how to inward click roll on my left side.

I think part of my problem is how much pressure I’m using but also not getting enough airflow in to make my tongue want to move in my mouth through my zipper. Is there a certain lip position you’re doing to make the sega sound that differs from the normal zipper on the side?