Alright folks, after a long wait, bumpstops are on the front dampers.
First of all, I ordered a set of the FCM 36mm bumpstops. 36mm Bump Stops
The bumpstops out of the box are about the same length or perhaps a little bit longer than the stock Bilstein stops. They're definitely thicker than the stock stops though, suggesting that the rate is higher, so I wouldn't recommend putting them on untrimmed.
Luckily, there's a notch right in the middle of the stop that allows for easy cutting.
The stop on the right is an out of the box stop. The stop in the center is my trimmed stop, and the stop on the left is the leftover piece.
Install was very straightforward, and I marked the location of my perch so I could get back to my height setting.
Now the Penskes come with rubber O-rings on the damper shaft. This allows for easy spotting of how much the dampers compress in use. Remember that the only problem I had with rubbing was at the bowl at Streets of Willow, a right hand turn the day I drove it. What's interesting, and expected is that the O-ring on the passenger side was a farther from the bottom mount of the damper than the one on the driver side. This suggested, not surprisingly, that the driver side was compressing more (due to the higher g-load from the bowl, which is a very heavily banked corner). I was hitting about 1 g of cornering force turning left, but saw about 1.3 g in the bowl. The O-rings were right at the top of where the bumpstops are on the passenger side, but were level with the lip of the bottom gold perch on the driver side. Thus, it seems that the added stops won't engage at less than 1g of corner force and so the stops should have minimal effect on the engineered behavior of these Penskes. They'll just give that little bit of extra stiffness in the bowl to prevent rubbing!