You should review these threads:
This has some data about oil starvation. Navardi currently sells his baffling solution.
https://f30.bimmerpost.com/forums/sh....php?t=1783473
This talks about accusump install on an N20.
https://www.2addicts.com/forums/show....php?t=1816447
This thread has, among other things, images and links to a dry sump solution. I would be very wary of going that way as you lose the balancing shafts.
https://www.2addicts.com/forums/show....php?t=1781019
There might be some good info on other threads as well but I'd start with those.