i, myself couldn't understand how to myself go fast like how you do in those 1-4 speedruns where they throw a core eject at the room.

but i know now so heres a tutorial:

1. equip jackhammer core eject
2. when you spawn in, dont go left or right. just straight
3. before you you go into the door trigger area, turn around and look down. not comepletely down though.
4. walk back towards the door and when you hear it open, use core eject and shoot it with a malicious railcannon