No, there are no special requirements!
The 316i is identical to the 320i (same engine), but the power is limited by the ECU (from 170hp to 136hp). At the Stage 2 tuning, this limitation is removed and a tuning is applied. So the performance after the tuning is the same as with a tuned 320i (210hp).
hope this helps, and if you need any further information, please let us know.