k, at the beginning of this he said he has a 97 legacy turbo... if thats true then he has a top mount intercooler which is what the hoodscoop is for....
the 91-94 legacy turbo isnt intercooled but the hoodscoop still helps vent hot air. i dunno maybe he just didnt mean to say 97.
like vrg said, subaru made it so you cant hear the turbo and BV in stock form. i have a legacy turbo motor with a hackjob intake and 3" downpipe so you can hear the turbo spool just revving it, but the plastic BV is still pretty quiet.
oh yeah and if you want to decrease the boost for better mileage, dont go full throttle! haha