How can the charge - between the throttle body and compressor - that is sent (by the bypass valve) to between the compressor and AFM, all get sucked back through the compressor if the throttle body is shut?
I understand the bypass valve equalises pressure either side of the compressor, but I don't see how in a situation going from WOT (and full boost) to closed throttle and idle, you don't end up (after bypass valve actuation) with pressure either side of the compressor which is equal but greater than atmospheric, and so you get atmospheric venting back through the AFM and POD/Filter. The volume of air downstream of the compressor (thanks to FMIC etc) is just too much to be equalised back to atmospheric by venting into the upstream side of the compresser?