A Sooty Intake (repost from old forum) ...

[Rawze]

(08-31-2016 )in2trux Wrote:  Can someone tell me why the compressor inlet isn't on the fresh air side of the turbo?
I didn't think the compressor needed to be turbocharged too.

The air compressor inlet does not need positive pressure on its intake piping, but if it were routed to the intake side of the turbo, there would be a strong vacuum on it. That could potentially cause problems with the air compressor head, and put the engine at risk for runaway (or coolant intrusion) if it failed.