Yes, there's a restrictor on the turbo inlet
U see that fitting in there? You see how small the hole in the center is? Yeah...
And yes, sr's arent the only ones that have baffles underneath their valve covers, many other engines have that too. If Im not mistaken ka have something very similar near the front covers, no? But the point is, you want to improve that. The more filtered the crankcase vapors going back into your intake without adding too much restriction, the better, no? That's why you want to choose the right catch can, not just a hollow ebay can that wont "catch" a thing, unless you're planning on modifying it.
This is what I went with:
