I'm trying to troubleshoot a problem. Here's the symptoms:

Whooshing/whistling noise starts around 3k rpms and builds with rpms.
If I go to 6k rpms and completely release throttle an air noise similar to a fast and furious blow-off valve purge is made.
The normal pull you feel from the turbos is completely absent.
Noises are worse when car is in gear than when I rev in neutral.

I'm working on this alone and don't have any help. I'm guessing the blow off valve is stuck/broke and needs replacement. Any other ideas before I drop money on a valve and replace it. Thanks in advance for any help.

 

You don't mention your boost pattern? The stock BOVs rarely fail. Usually it is solenoids or check valves.

Read this:

http://www.autosportracetech.com/RX-7/rx7stuff.htm

 

I would check your intercooler hose connections. Especially the one off the y pipe.