Do you know what this part is called?

There's a part that goes on the top the supercharger, it's a black piece that a vacuum hose hooks to and its near the pcv. Does anyone kno what it called? this is a 98 GTP

This Part?

ZZP calls it a blower booster cap, but I dont think thats its official name.

http://www.zzperformance.com/grand_prix/products1.php?id=1033&catid=106

Thank you I got it ordered!!