I figured it out. It was a coupler it didn't blow off it ripped open at bottom. Shue sent a pm also

 

....exactly.... there is no way that it would be the vacuum line going into the boost controller. If the signal is lost to your boost controller, the boost level should actually max out since there is nothing (no signal) that tells the wastegate to open. Unless as Chris (fabrik8) said, wastegate is not closing properly or is not seated properly, internally or externally.

 

actually.... he has a 7 psi spring sooooo if the signal line whas off it would only boost to 7 psi.... with a fmic it would be resonably 6 psi at the manifold or guage.....

with a 7 psi spring and a mbc set at 14 if the signal fails it maxes at 7.......

how it works

a blown coupler usually make a loud surging noise...... but no one told us that

 

my friend had a problem like this before. i think it was from not having his wastegate adjusted properly, so the spring inside the wastegate gave out and wouldnt build up as much pressure as it should have been. so i would check the spring