I have a 2000 Mustang GT with a KB supercharger and JLT Ram Air Intake. At ~5000+ RPMs, there is a loud sucking sound (so loud it almost amounts to a shriek) coming from the intake/air filter area--wondering if this is normal/typical...here's a video where you can hear it clearly:
View: https://www.youtube.com/watch?v=G6rIECbaYsQ
View: https://www.youtube.com/watch?v=G6rIECbaYsQ