I worked a lot with engine boosting systems, to me, those 2 planes had what appear to be turbochargers.
In fact, one cheap and dirty way of plumbing a turbo on a car is to locate the turbo back where the mufflers would normally go. Makes me wonder if someone got this idea from the P-47??
In regards to the P-47, all the turbo plumbing would have made an additional layer of protection for the pilot. Yes, the pilot would have lost power/boost if hit in these areas but his plane should have still been able to fly.
Turbos make fairly decent mufflers on gas and diesel engines, mufflers on these vehicles don't have to have the sound supressing qualities of a non-turbo car/truck.