SHOSource catless pipe sound issue?

[LJRuddy]

Ever since I installed my SHO Source catless equal length y-pipe, I noticed a unique sound at 3,000rpms during engine deceleration. The sound is VERY similar to a blow off valve. In fact, I have had multiple people ask me at stoplights if my car is turbo'd as they too heard this "hiss" during shifts. I can also hear the hissing noise during hard acceleration starting at 2500 rpms. As the rpms increase, this hiss becomes louder and louder IDENTICAL to how a turbo would sound as it spools up. I chalked it up to a loose heat shield ersumshit. Well, one day I decided to check for loose heatshields or anything that would make this noise and I found nothing that could possibly be doing this. Fast forward to yesterday....


38SHO posted a video http://www.youtube.com/watch?v=2lHzHYD9rmM

And between :45 and 1:00, you can hear the blow off valve type sound during his 2 shifts. If you listen carefully during his acceleration when the passenger is holding the camera, you can also hear the "turbo spool" while he is accelerating. You can also hear it VERY well at the end of the video when he throws a few revs in front of the fence.

What the **** is this noise? How does it happen? How can I eliminate it? Some days this hissing sound is so bad that I can hardly hear my secondaries in 1st gear with a concrete jersey barrier 2 feet away from me.


38SHO, hope you don't mind I used your video for this thread.