On calipers not rotors. Sounds like it a " no worries" thing

 

honestly my pistons dust boots have been toast like forever lol
i always run my pads down to the backing plate and seems like for over 20 track days the calipers are still doing fine!
id say just dont worry abt them until brake fluid starts to leak out somewhere =p
dont take my words for it tho, just seems everyone's boots are toast and no one is really having any problems...

 

I meant its normal every where in the country. its usually only on the rotors.

 

My car has perhaps 30 track days on it, and untold autocross runs. It's been retired from track duty for four years now, but I never had an issue with the dust boots; they're still fine. I went through many rotors, many pads, but never had a problem with dust boots.

I did put front brake ducts in (since removed), but that was after a non-trivial number of track days.

 

Greg, try getting a bit more cooling time. Not sure how you end your session but I usually finish my session by trying not to use the brakes too much but still keeping the speed up along with a couple laps around the paddock and even then they're still around the 600* F range.
By boots are a bit crusty on the edge closest to what I would call a view port the hole on the caliper where you can see the disc & pads.

I went from 12's to XR2's and I think you'll like the switch.

If you want your rotors, pads, bearings, calipers and really anything else around there to last then cooling them down afterwards is super important and for me it's part of the session. Watching my pads and rotors smoke after a session is like watching money burn.

 

You should also clean out the slider pins and grease them. I use a grease made by 3M that's seems to work nicely. The factory grease was toast after like 4 or so track days, the caliper just starts sticking instead of sliding smoothly.

If you do plan on running bootless make sure you clean the piston real good before pushing it back in for new pads. Don't rely on the seal for that job and as far as I know there isn't any race caliper that uses dust boots.