Geez, E30's have a lot of room in the engine bay...
Do not let that picture fool you.
There is quite a lot removed from the bay in that picture. Yes there is room to work, but not much in terms of room for turbos and such.
Notable items missing, washer tank, fan, shroud (which is huge), and airbox, which is also huge. Granted most are easily moved or changed, them not being there at all makes it look bigger than it is.