The OEM intake piping is both lengthy and restrictive, the result is a pretty high pressure drop at the turbo inlet. Try breathing through a small straw, it's a struggle. Move to a larger straw and you can breathe FAR more easily. This is much the same difference in breathing - the engine is an air pump of course. The MAF sensor is small to be sucking all that air through as well btw.

Removing the restrictions means faster spool and higher airflow, better driveability and power! The Y-pipe is restrictive too but to what extent is an open question IMO and I don't think it's as critical as the intake. Lastly, the throttlebody is supposed to be a restriction, it's pretty damned small for the amount of horsepower we make!

So, free the intake tract to whatever extent you can and enjoy more power throughout the powerband.

 

^^^ I agree. That factory piece is one of the worst I've seen on a turbo car! But hey, I guess it does it's job.