allright...just got turbo installed and i drove it to muffler shop so that they can create downpipe. yes the turbo whined some....more of a whistle. after downpipe.....i boosted for the first time and shorlty after i heard the turbo scraping on the compressor housing. sure enough...the 3/8 lock nut came loose. about 200 ft further rolling from the time i heard the scraping. i tightened it and now the turbo whines a lot. more of a deep cough and not a whistle sound. as sson as the "deep cough" goes away all the power kicks in. my theory on it would be that i tightened the nut to tight and that the fins have more pressure and are straing the bearings. i drove home.....and lossened the nut once again.....it is just snug now (less then the 18 inch pounds) but it still makes this noise.

questions are.....can i reuse the lock nut or is that a one time thing.
do you think i tightend the fins on to tight so that when i loosened the fins they didnt slide out?