I recently had a borla catback exhaust system installed on my 02 wrx and today I just put an invidia downpipe on, the install went well pretty easy for the most part but there is some sort of whiney noise coming from it now. It might be the turbo but Is this normal or did I do or not do something to make this noise any suggestions please, thank you
-Brett

 

Yeah I know hoe hard it is to diagnose a problem without having heard it. the best I can do to try and explain it is sort of a whistle that gets louder the closer i get to WOT. Now when you said your turbo intensified greatly was it almost annoyingly loud, to the point people can hear it when you drive down the street. And another question is there a different satisfaction you recieve with how much you spend on a downpipe why is a helix dp 400$ and an hks or noname brand with bellmouth go for 150$