OK, here's some more references recommending higher pressure:
http://www.tirerack.com/tires/tirete....jsp?techid=58
This recommends higher pressure on the track than on the street:
http://www.motoiq.com/MagazineArticl...-Pressure.aspx
This one recommends setting pressure by temperature which seems like the right thing to do. But I lack the equipment. It also suggests setting cold pressure and only fine tuning hot. I agree completely with that, the cooling time affects the hot temperature making adjustments much more difficult.
http://www.trackpedia.com/wiki/Tire_pressure
This one recommends the same sort of testing I did and illustrates it. It doesn't really recommend high pressures although it says he runs 38-40 in front:
http://racingready.com/2010/05/27/ti...s-tuning-tips/
I will know better what Michelin PSS want after I actually get to use them in an autocross. But I will start at 40 psi and not be surprised if I have to go up. But maybe I will be surprised and have to go down. We'll see. I will probably mark them so I know if I am on the tread or the shoulder of the tire.
I will also point out what I said in the first post I made, a lot of the one lap of America cars were running Michelin tires which seemed to be PSS. Surely one lap cars are viewed as having pretty extreme duty. They were also on a M6 I saw at the dealership. I don't think BMW would pretty tires prone to chunking on a M6.