Sounds about right. Should be slightly less than the ATS-V rotor since the V2's hat isn't as tall.

Edit: Weighed 2 used V2 2-piece rotors, 26.5# and 26.6#.

 

After posting all that info back in 2017, I really hadn't done anything with the rotors, because I had some modified V2 rotors on hand for track duty and was able to use those through the end of the 2018 track day "season". In 2019 I didn't get to any events, and this year I haven't done any events ... until this coming weekend. My pair of modified V2 rotors were used up, and I had actually removed the hats from the rings (as seen in some of the pics I posted 3 years ago), but hadn't gotten any farther than that. Well, with an event coming up next weekend, it was time to figure out using the Vette rotors.

Back in 2018 I actually ordered some hardware to reinstall my existing hats on new rings (from new GM / Brembo rotors). The factory bolts are M6-1.0 x 30mm and are grade 8.8, so nothing terribly special. I ordered 50 6M-1.0 x 30 grade 8.8 hex head bolts from somewhere - maybe McMaster-Carr? The nuts were a bit harder to get. They use deforming threads to lock onto the bolt, and are sometimes referred to as K-nuts (there's even a brand of that name - https://kl-projects.be/motorsport-ca...ts-anchor-nuts). I found plenty of places that sell standard / SAE K-nuts, but not many that sell metric K-nuts. When I did find them, I found 2 different specs - normal (rated to ~250C) and "high temp" (rated to 450C, or even higher, depending on which site I looked at), with the latter costing about twice as much. I wasn't really sure if I needed the high temp spec, but that's what I ended up buying - figured it was better to be safe than sorry. Unfortunately it's been so long that I'm not sure where I ended up getting the nuts, but as I recall it was from Demon Tweeks in the UK, because even with shipping from the UK it was cheaper to get them over there.

This weekend I finally got around to disassembling the Vette rotors. As previously discussed, the Vette hats are a bit different, with wear strips (for lack of a better term) that slide into the slots on the flange of the hat where the bobbins mount. Those wear strips ensure any movement (due to the floating aspect of the hats) is steel-on-steel (steel bobbins and steel wear strips), whereas the older V2 hats are steel-on-aluminum (steel bobbins directly against aluminum hats).

I'm sure GM / Brembo have a reason for putting those in there, but I don't see any sign of wear or anything unusual on my re-drilled V2 hats, so I'll continue to use those. Eventually I'll get around to re-drilling the Vette hats, too, but for this weekend's event I figured it was easier / quicker to put my existing V2 hats onto the Vette rotor rings. I used all new hardware (I'm not really sure the bolts need to be replaced each time, but that seems to be what Stoptech, Girodisc, Racing Brake, etc all do, so I figured I'd follow their lead), torqued to 110in-lbs (based on what I read from KNS Brakes - more on that below), and then used some threadlocker that came with some Stoptech rings I bought for one of my other cars.

In the 3 years since I last updated this thread, Girodisc and DBA have started selling rotor rings for these "non-serviceable" GM / Brembo OEM 2-piece rotors. I don't know who else may sell them, but I know they're available through KNS Brakes (www.knsbrakes.com). If you put in that you've got a '17 Corvette Grand Sport w/iron brakes, it'll show you the available rotor rings and hardware. It's borderline whether the Girodisc or DBA rings are a better deal than just buying the GM / Brembo complete rotors from Rock Auto or Amazon, but the Girodisc and DBA rings are supposed to be better quality (better iron composition, more vanes) than the OEM rotors.