I don't know how it'd work out with 116i but putting on LSD on M135i helped, maybe that's something to consider.
If you have decent tyres on the 116i, an LSD does not make all that much difference, as the car is not really powerful enough that wheelspin is an annoying issue. The fake differential built into the car can handle it rather well. Maybe it will be more worthwhile with a 200+ hp ECU tune.
