PIR sensors are probably the worst sensor for a 'speed' gate.
They are designed to react slowly to changes, to stop false triggers.
Probably just ok for grannies in a walking frame.
If you use the sensors you linked to,
then first turn the 'time' pot fully couterclockwise, and the 'sens' pot fully clockwise.
That will give you the shortest reaction time and the shortest 'stay on' time.
Leo..