Which gears
 

I have a ?... If I'm running nitrous, I should I only use it on 1st, 2nd and 3rd gears or can it be used on all gears?

It depends.

well, gettin rid of the retards answer, here's one from a guy who has actually done performance stuff and driven his car in a performance situation.



im gonna assume your car is a 4 cylinder and a manual transmission. when i sprayed using a regular 75 shot and a non progressive controller, i would wait until i shifted to 2nd gear then hit it and sprayed for the remainder of the track.



if you happen to be on a desolate abandoned race track in mexico, its recommended to not spray for longer than 10 seconds cuz you run the risk of a nitrous backfire



happy spraying and remember, ask questions BEFORE you blow your motor