Drive : parameters of speed controller

We are doing an upgrade of old drives (Siemens Masterdrive) to new ones (Siemens Sinamics). We know we should tune the speed controller of the new drives, but because the mechanical load is not very simple we would like to know if we can convert the old P and I values of the speed controller to the new drive.
Difference is that in the old drives, the speed controller is running at 0.4 ms cycletime, and in the new drives at 0.125 ms.
Does anybody have an idea or experience with this difference in cycletime of the speed controller, what the new P and I of the speed controller should be?

I'd retune it. Even if you find some sort of conversion from old P and I to new P and I, I'll bet you will still need to manually tweak it to get it just right.