Originally posted by rweis
I found that after a "little surface dirt" on the Scotty II filter (about 6 months of driving in a fairly clean street environment) that the turbo compresser section sounded "better". A little dust film on the Scotty II helped quieten it down some. I was going to thouroughly clean it annually, now not quite sure how clean I want it. Maybe a prefilter may help tune it to my taste.
Hummmmmmmm, put one filter somewhere to sort of prefilter, duct it to the Scotty II to really filter it. Might have a bearing on the "tunes", rather than just one filter sucking "ambiant" under the hood / cowl air.
Bob Weis