some mice mentioned my name.....
ok,
if you have the standard e30 suspension setup, or tuners setup meant for the e30, then 16" is about maximising the suspension treshold
simply because the extra rotation mass will effect the suspension balance and the extra unsprung weight of the 17"-if its replica- even heavier then normal, will create an imbalance in the suspension dampening and rebound rates
if you have the original BBS 17" made for the e30s - ever so rare here, then you might just make it in within the treshold, provided you have the tuned system, i.e. bilstein&eibach, H&R & konis, etc,etc
if you use aftermarket replica rims, you will get feedback like most of the drivers out there, improper balance of the car.....
so its not about the size of the rims, its about a system and a balance be it 16",17",18" etc
mine and Alvin's has similair setup not the same but similair, i would say my current setup is as close to my old e30 bilstein&eibach suspension setup, if not a little more firm
you can still run after market 17" replica, but a total suspension revision is needed, i.e coilovers, PSS, etc to match and balance it out.......