Do yourself a favor and disconnect the AVC-R, at least to troubleshoot this. My blue car did the SAME thing, it was laggy as hell with just a big16g. First I hooked the boost line straight to the WGA, and verified I got 12psi, nice and prompt. THen I got a nice cheap (but not ebay) MBC (it was a DB Performance one), and put it in. I have it dialed in for ~18psi now, and it is perfect; nice and smooth power to redline, boost kicks in right where it should. AVC-R is currently being ripped out of the car
