Car wont boost past 5 psi

[herbieS13]

So my car recently stopped boosting past 10psi now it wont boost past 5 psi i bypassed my boost controller to rule that out, no change to max boost levels or response, then i pinched off my vacuum line to wastegate actuator to see. If it would build boost past 5psi and viola it did so i switched out my actuator with a known working one and now it still wont boost past 5 psi it acts the same as before. It acts and builts normally to 5psi and then it seems to max out there. Im stummped from here i have a feeling it has something to do with the flapper on the turbine housing. So i guess im looking for a confirmation or second opinion turbo is a 2871r motor is sr20 stroked to 2.2

[herbieS13]

well no body could answer my question so i took it upon myself to do some further investigating, turbo is bad. i looked at boost charts from tune day and a chart from a pull today and it shows turbo is much more laggier and does not build boost properly (as i already knew)

[cotbu]

You need to do a few things first, check the turbo for shaft play. Do a boost leak test and check turbo to ex-manifold and ex-manifold to head gaskets. They would all give in some way the symptoms you describe. Secondly post a video and maybe even check for codes. Sometimes the blown gaskets and vacuum\boost leaks make a sounds that the average person will not notice. I know what my engine sounds like at idle with and without the my silencer installed. If it ever sounds funny? I investigate immediately.

The internal wastegate builds boost when the flapper is shut, and regulates by opening.
I'm gonna assume you left the boost source connected during your first test and was able to build boost, correct? Where did you pinch the line? You can add compressed air to the internal gate to rule out a busted bladder. If the bladder doesn't hold pressure, you found your boost leak. PS i could fill up your thread with a crap load of speculation but I won't. So post that video, even if you get it figured out.

[herbieS13]

thx for insight but i went ahead and got a new turbo