Correct this a “pre-boss” filter. Like the D+ I do not believe we have ever seen one of these with failed media, but they aren’t usually beautiful... this one is actually pretty ugly looking.
I will try to dissect the media by the end of the weekend. I believe this is wire backed and single layer but am not positive about the layers.
I want to look at the media more closely, I don’t see any tears or splits, but there are some spots that may be fatigued, a closer examination is in order. This filter was on for almost 2 years and the car now sits out under a carport vs in a garage as it did here. The combination of environment and longer than average run may account for the worse than average appearance.
As stated this particular number (and others that use a similar baseplate) cannot cut the ADBV like some of the other ones do. I have a number of similar Puro made filter dissections for this application posted here and the ADBV always looks fine.
Everyone is of course welcome... the UOA arrived at Blackstone today, so perhaps we will have it back soon as well.