I go just on wednesday to look around in the years of attending the spring & fall Carlisle events pickings for turbo parts are slim to none. For awhile back in the late 1980s you could find take offs from the GNX project such as wheels and tires (GN).
Now lucky to find a stray center cap among sellers of wheel parts....Englishtown is usually better.
Just my findings....I go for the fun and to take my brother as a day out with him....By going wednesday I avoid the huge crowds,long lines of traffic amd lines for the johnny on the spots...