A few random notes:
(1) First, an install note that I don't think I covered previously. I know it has been mentioned that the V2 uses larger diameter caliper mounting bolts (14mm vs 12mm). The V2 bolts are actually a bit too long (in other words, the V1 knuckle isn't quite as thick as the V2 knuckle where the caliper bolts up). As a result, the OEM bolts will actually touch the back of the center hat section of the OEM V2 rotors. I initially shaved the bolts down a few millimeters, but that resulted in some ugly threads on the end, so they didn't thread into the calipers by hand very cleanly. I have a thread chaser set, but the only 14mm chaser is the wrong pitch, so I couldn't clean up the threads as I would've like. So, I went to Fastenal and bought 4 grade 10.9 (same as the OEM bolts)
14mm-2.0 x 45mm bolts. (The stock ones were ~49 or 50mm long.) They work perfectly; you could just go straight to that option rather than ordering the OEM V2 bolts. I suppose the other option would be some thick 14mm washers under the head of the V2 bolts - I'm sure there's a reason I didn't go that route, but I can't remember it now.
(2) I finally got to do a full track event with the V2 setup and I came away
very happy that I went through all this effort. I don't have any objective data to refer to, but the brakes felt great and I never once felt I needed to take it easy for a bit to let the brakes recover. When I still had the V1 setup, the lead instructor at one of the events asked me about the brakes and how they did with such a heavy car. I told him that with my Subaru [normally aspirated, thus slow, and obviously much lighter than the V], I can go
deep into a braking zone and even though I'm braking very hard, there's still more there. If the guy ahead of me slows down more than I expected him to, I still have braking power left in reserve. But with the V, I always felt like I was using all the braking capacity I had, and it just wasn't as confidence inspiring. Obviously, others find the V1 brakes to be more than enough, but that's how they felt for me on track.
With the V2 brakes, I feel as though I have that reserve now. Going into turn 1 at VIR (upper 130s down to ~45mph) I was able to take some late point-bys, take the inside line, and comfortably haul the car down.
(3) I'm out in the garage putting the street rotors & pads back on and figured I'd post up some weights:
OEM V2 rotors - 25#
Racing Brake 2-piece V2 rotors - 23#
(4) I'm still curious about what rotor options are out there. As I've previously mentioned, Centric now offers a rotor for the V2 - #120.62128. I haven't found an actual picture of one yet, but on RockAuto.com it says it's co-cast (like the OEM rotors), and the weight is about the same as I just measured for my OEM rotor. (If the Centric part was
not co-cast, I would expect it to be quite a bit heavier since the center hat would be cast iron rather than aluminum.)
Rockauto.com also has two different varieties of ACDelco front rotors - 1-piece #1771105 (co-cast rotor, corresponds to GM part #25851237), and 2-piece #1771145/1156 (corresponds to GM part #20795300/302). The 2-piece rotors are "only" $297 on rockauto.com, which is pretty damn good. I'm curious if the rotor rings are intended to be serviceable, or if they're basically "throw away" 2-piece rotors. I've done a bit of searching around today but haven't found any info on that yet. If they
are replaceable they would be a helluva lot better deal than the RB option!