So lately when i've been driving my car and boost i hold strong at 10psi on the first turbo but when it switches around 4200RPM i feel a drop and my boost controller reads only 5psi. Sometimes, and its not often i do still get full boost on the second turbo, usually in gears 3rd and up.

I did some searching on the forums and from what i found its one of three solenoids:

Turbo Precontrol

Charge Control

Charge Relief

I'm going to go digging into the rats nest soon with a mitivac and test those solenoids see if any are bad, but first I wanted to see if anyone else had any other ideas on what it could be or other things i should check while i'm in there.

Though it prolly doesn't matter, i'll list what i have done to the car:

Intake
Full 3 inch exhaust, no cats
Power FC (newer base map)
Greddy Profec B boost controller

 

You sure that's just not the secondary turbo transition? lol

thewird

 

No it holds 5 psi up to redline i mean.

 

No one has any other possibilties?

 

Even if it did come back up, the transition (if working properly) should only drop 2-3psi and be VERY fast.


Vacuum lines are of course a possibility. It was annoying things like this constantly happening that finally drove me to single.

 

Hopefully it is just a popped off vacuum line. That would be great haha.