Boost Drops From 13psi To 8psi Throughout 4500rpm And 7000

[Visionaree]

foot flat boost sits at 13 fine before 4500 but after it drops slowly down to 8. is that a leak?

[89CAL]

could be a leak or restriction, check your cooler pipes are all connected nicely and done up tight, Your intake pipe might be closing in to (rubber pipe from turbo to afm)

depends on what setup you've got, post up a bit more info

could also be your boost controller? manual or electronic?

More info and I'm sure someone will be able to help sort it out

[Visionaree]

stupid me sorry lol its running the stock cooler and a manual boost controller. so your saying that the rubber hose could be sucking itself closed? well not closed but smaller. hmm thanks heaps for that il check that all the pipes are tight.

[turael]

the rubber pipe should have a metal spring in it to stop it from being sucked closed.

boost should taper off at the end of your rev range, but probably not that much, what boost controller are you using?

[tridentt150v]

wastegate creep???

[mad082]

running 13psi through the stock cooler probably isn't the wisest thing in the world to start with, and that may be part of the problem.

other possible causes:

boost controller issue

dump pipe issue (what size exhaust do you have)

boost leak

blocked or damaged cat

fuel or timing issue