Boosting prolems

[racinmasonc]

Hey guys.. this is what is happening.. MBC set at 17psi on the evo3 16g with the 7cm housing... the psi goes up to 17psi and holds for maybe 2000rpm, from 5000 - 7000.. the full 17psi isn't hitting when it should. this is what i'm thinking it could be:

My upper IC piping is very flexible (stock) you think by that when it sucks in the airflow drops dramatically? then under boost it'll eventually expand??

there is a hairline crack in the exhaust manifold, it might be all the way through, i don't know for sure... could that be the cause of it??? its hitting full boost in 2nd gear at actually 5500 rpms..

 

[BC91AWDTalon]

if you have a crack in your exhaust manifold that can definitly lead to boosting problems, also have you tried a boost leak down test...

if you dont know how to do one look on vfaq.com im pretty sure they show you how to do one..

 

[bojanglesracing]

my friend had a problem like that turns out his piping was to small at one spot. was not letting enough air flow.