First of all, you have to be aware, that your code is framerate independent! After that, you need to set the "fps_max" to "60", which is probably the best for the most type of games. If changing of the fps affects much on the movement (rotations etc), this means that you've coded your game wrong.

Read manual about this, and probably there was something about it in the workshops, take a look as well:
http://tutorial.3dgamestudio.net/
http://www.conitec.net/beta/atime.htm