What is the purpose of this?

2007 T800
C 15 NXS Accert (born 475hp)

Seem to have lost a little power lately, coming off the fault code #95 & #93, along with main wire harness near shorting secondary ff due to rubbing on a bracket; it's a wonder engine ran at all. My bil, who has the same engine but a 625 hp in a 2007 Pete, advised me to check the largest pipe coming off the top of air compressor. After much searching, he found that the short (approx 3" long x 1" diameter) red hose that joins the hard pipe from from the air compressor to a box just ahead of the secondary ff had a split on the backside- soapy water made his engine look like a bubble bath. Ran outside with my spray bottle, and sho-nuff, bubbles everywhere! Bil was told this pipe / box has something to do with the wastegate system on an Accert. Pete sells an upgrade- (ss wire braid hose & two fittings). This was late Friday afternoon, and 55 mi. from nearest KW dealer, so I wound up with a short piece of blue coated silicone hose. Guy at hose store claimed it was high temp / pressure suitable, so hope it will last till I can get this upgrade. (No, just my luck, hose store didn't have the correct fittings to make up that size ss braid hose). The guy also didn't have a lot of confidence in the ss braid hose due to one downward bend + dog leg bend, all in a total length of about 24", concerned about kinking.

This hose (pipe) is as stated before, the largest of the three, my KW, and bil's Pete both were (1) hard pipe,
(2) one ss braid hose (air supply to drier), and
(3) a hose (intake air, or coolant I think) on top of air compressor "head".
Just curious as to the function of that pipe & box setup?