Hi i was wondering how i would go about submitting a speedrun on xbox 360 portal 2

From what I can see it looks like video recording of the run is what is required

Any need for timers?

record the run and then u can time it afterwards for an accurate time

it is usually a good idea to run with a program like livesplit to get a more accurate idea of your pace throughout the run. it also makes retiming easier for mods (probably), although it is not required for submission.