I think 60 fps is the current cap (on the Go), not sure if you can increase it. I think the reasoning behind this is the human eye can't perceive much more than that. I know it does have an effect in FPS specifically, but I don't think there is currently a way to uncap the framerate. This is deprecated but it looks like 72 fps is possible on the Go - Rift can go up to 90 it appears - https://developer.oculus.com/documentation/unreal/1.25/concepts/unreal-dynamic-fps/