I'm not 100% sure, maybe others with the stock turbo and HKS SSQV can chime in. Personally, I never got the flutter sound when I had the HKS SSQV paired with the stock turbo, but you will still get the iconic high pitched HKS blow off sound that others have posted on this thread with the stock...
Do you mean flutter like this?
^That's @SBX Performance 's car when he had the Kuro turbo and RV6 bypass. My MHI Stg 2.0 turbo and HKS SSQV vented to atmosphere does that same flutter.
Yup, what ABPDE5 said.
I've been running the HKS SSQV to atmosphere for a couple months now without any problems. It's been my favorite mod so far. That chirp between shifts is too much fun. If you're getting the FL5 kit, the install is a major pain. See the other HKS SSQV thread for some...