Ok ive just fitted a H&S downpipe and centre pipe on a my02 wrx it has also got a jap box fittted to,it was loud with just jap box on but now (bloody hell) sounds even louder in a nice way tho,its seems to make a good deep throaty rumble after 2000-2500rpm.Anyway when i get to about 2000rpm i can hear the turbo whistle now but couldn't before, just wondering if this is normal after fitting this pipe,im still not to sure if its made alot of diffrence performance wise,sometimes it does tho.I think i was just expecting alot more performance,but alot of people say that it takes a little while for the ecu to sort itself out.Just wondering if anyone had anything to say on this cheers steve