i have been having a similiar problem at about the same rpms, i just did a post on it the other day.my boost doesnt seem to have a problem when it happens, someone else mentioned exhaust baffles. strangly the noise has seem to gone away. i am thinking it was something loose in my muffler . gonna change exhaust soon anyway so maybe i will find out then. if you are in the portland area you can call me @ 503 257-5106, i would like to hear your noise to see if it is the same . good luck
94 6.5l turbo engine code f
homemade fsd/pmd cooler
k&n air filter
many goodies coming soon,oil cooler lines and 3.5" exhaust
lots of 67-69 camaros