I have found a way to double the fps (from 33 to 66) with out increasing the look of the game speed. It needs empty's mod to work. I set to sync rate to 60 and then halved the speed of all the dynamic entity's.
1. Put this script on a dynamic entity and set it to always active.
2. Half the speed value on all the dynamic entity's (including player marker, doors and windows).
There is one problem, that the player gun is twice the speed, which could be fixed by halving the speed of the animation.
I will upload a working demo of it, if you like.