ok, so i just bought a greddy type s bov (recirculation) . i hook up all the original hose right. but there is a little port that come out of the valve and i don't know where it goes to. am i suppose to T it off to something. please help. i'm new to audi.

 

i believe you refuring to the 2nd vacuum nipple so:

The small hose you removed from the stock BOV must be connected to the larger nipple on the anodized cap (closest to the adjustment screw.)
(Note: This connects to the intake after the throttle butterfly and will pull vacuum when the throttle is closed)
The smaller nipple on the cast aluminum body of the BOV may be spliced into the turbo outlet pipe or into the line between the turbo and wastgate actuator. Use the T-connector supplied. This connects to pressure even when the other line has vacuum. This will activate the BOV faster by applying pressure under the valve seat.
The smaller nipple may also be left unconnected. The BOV will operate slower and more quietly. I did not test this mode.

from http://herpetology.com/dsm/bov.html