Oil galley over pressure during boost???
 

Need some help from the 2nd Gen folks due to me having a s4 TII motor.
This is what I have:
s4 TII stock porting with a Garrett .60 a/r.84 turbo, s5 LIM, s6 UIM and TB
550 primary, 850 secondary injectors
MSD LS1 coils
44mm Tial Wastegate
Haltech Sprint RE
Greddy Profec boost controller
FC front subframe conversion

I'm getting huge over pressure when hitting 14lbs boost...blew the oil filler neck off...with a breather can/filter installed.

This is my first Turbo build so I don't know a whole lot.

Can someone help me understand why at peak boost the oil is coming out of the oil filler neck?

Thanks for your help.

...Reference pics were before the breather tank was added.

Is the engine a recent build? What were side seal clearances set at?

excessive side seal clearance or worn oil control rings can cause this, ive also heard running excessively rich can contribute as well if your tune is a ways off...

may be a good time to invest in a oil catch can, I ended up installing one on my fc I just had a turn down hose off the side of the fill neck , resulted with oil all down the side of the motor

loosely built engine

S4 T2 stock port? Sounds like it's time for a rebuild and a mild port job. Redo the side seals too.

How about the hose barb on the side housing? You didn't put vacuum/boost to that did you? you could be pressurizing the crankcase.