Im running 7psi right now and everytime I punch it in 1st and 2nd gear boost drops from 7 to 4-5psi after 4k rpms. I have tightened up all my cuplers and dont seem to have a exhaust leak anywhere. In 3rd and 4th gear it drops about 1psi after 4k rpms.I have a joe-p mbc but I had this problem before I put the mbc on too.What can be causing this?

bad internal wastgate? :shrug

Originally posted by cartuners00
bad internal wastgate? :shrug

Doesnt the mbc bypass the wastegate? Could it be anything else?Because it drops the most in 1st and 2nd gear

why don't you try taking the MBC out and just run the line to the WG. See what happens.

Originally posted by Blizare
why don't you try taking the MBC out and just run the line to the WG. See what happens.

I had the same problem before in installed the mbc.