WELCOME to the "darkside"!
hey man, do you have a B16 swap or you meant B16 drag kit converted to fit a D engine?
if i remember correctly, i think that the DRAG kit pushes 7 psi. that's what that red 7 mean on the deltagate. 7 lbs is the spring tension on the wastegate. you need to re-check all your piping clamps and vacuum line to ensure tightness. you may want to re-check the setting on your BOV. if it is adjusted right, you should not get any compressor surge OR at least MINIMAL. i still get some on mine. another thing to consider, if the BOV is maladjusted, it will release pressure under boost which MAYBE the reason for a 4 psi reading on your gauge.....but re-check all your vacuum lines first. a 3" exhaust piping is ideal even with a smaller inlet on the muffler. u can always get a different muffler later on. do not worry about that for now, it will still flow better than a 2.25 inch all the way. i say get an extension for that dump pipe. keep it away from the interccoler. expanding hot gas over an intercooler will reduce the effeciency of that intercooler.
GOODLUCK man
