Just wondering how much surge is too much for a turbo, before damaging it. Sometimes in very low boost (1-3 psi) I get the surge sound. Running the type S greddy bov. It already is adjusted out pretty far. Once the boost is above 3 psi, no surge, just the psssttt.

So at low boost, am I damaging the turbo? Thanks!

Yes. It does.
also I recommend to take your BOV apart and inspect the membrane for cracks and damages. Turbo starting to surge a little while in boost is a sign that something with your bov (or vac line) is not were it should be.

Without the bov, the turbo will surge even when in low vac, let alone any boost, and surge is bad for your turbo, as it puts too much stress on the bearings.

get this: http://www.rx8club.com/showthread.php?p=2041774

no chance of getting surge. It seals at -10 psi and above, and opens up again when you hit -10 psi or under. When not in boost, it's open.