not building boost, am i missing something? Options

[easternpiro1]

Hi all, was wondering if i can get some feedback on something i was missing. here's the story:

recently a friend and I fixed a leak due to stripped thread in the head causing a leak between the exhaust manifold and block.

after rethreading and putting everything back togehter leak is gone BUT now im seeing much lower boost numbers after taking it for a drive.

I own an AEM tru boost controler/gauge and the boost is currently set to stock wastegate pressure (8psi) and consistently held this pressure PRIOR to fixing the exhaust leak.

as of today, my first drive out, my car would not pull past 5psi and touched 6psi BRIEFLY. I double checked my IC piping and adjusted and retightened.

when i went back out the car would only boost up to 4-5 psi adn sometimes as low as 2-3 max.



Im pretty sure its a leak somewhere but it can only be one place as the only IC piping that was removed was the piping coming from the turbo (charge side) i have checked and double checked it.

is there something im missing? any helpful hints would be appreciated! thanks!

[easternpiro1]

in all my troubles with turbochargers and boost on the 3sgte, the problem has ALWAYS been too much boost.

when my original ct20b went out, it made a very loud whine like a dieing animal, and then it made 0 boost as the turbo shaft snapped somewhere in the centre cartridge,

my car has always been able to make atleast 10psi boost with the clamps undone so i highly doubt its "just a boost leak"

also, using a 3psi spring in a 44mm tial wastegate im still getting creep up to 10-12psi

sounds dumb, but did you overlook checking out both sides of the turbo? you spun one end freely, but did that equally spin the other end??? to me it seems theoretically impossible to make 0 boost short of not having the turbo hooked up at all

hey mate, I heard no loud whine, but I have checked my cold side and hot side before no shaft play, and both spun freely. some friend and i were kickin some ideas around and we believe my wastegate flap is staying open somehow. but there is no way to tell short of putting it on a dyno and putting it under load to see. I am going to take my downpipe off again to be SURE there is no play and in going to look at the fins on the hot side to be sure theyre not chipped or anything (which i doubt)

that new wastegate I have is VERY stiff, so i couldnt understand why i was still gettin no boost until a pal of mine said it may be so stiff that its just stuck in its position. so this is prompting me to take off my downpipe and look at the flap to see if it is open a crack, as he says this would cause me to build no boost EVEN if its just open slightly

Have you tried using a boost leak tester, it's easy to make one.
Cheers: Dom

thanks dom, yeah i used a home made boost leak tester and put it on the intake side of the turbo, i only turned it up to like 3-5 psi but i heard no leaking air its looking like this is either turbo or flapper issue