As far as flutter with the pink spring, under normal driving i've been having clean vents free of flutter. There was one specific scenario where I vented it around 6500rpm testing it, and under that load I was getting some flutter which means I have to go just a bit softer. But from what I read on the Evo forums was these springs tend to 'break in' and soften up a little with regular use. So I'm going to wait at least a few days before I try to soften it any more to let the spring get settled in. Next few days will just be driving to the office so I won't be driving like a bat out of hell anyways
And damn does this thing sound good, can't imagine the sound with the vortech race valve that Top suggested.
Thanks again for all your help guys, without the support on the forum I probably would have just returned the valve and tossed the bosch one back in.