Girodisc Rotors (X Front, 8/9 Rear)

Just purchased and mounted new 2-piece Girodisc rotors for both the front and rear. This replaces my old DBA5000 front & DBA4000 rear setup.

These are super-light high-end 2-piece rotors that look great and decent amounts of weight. While the previous DBA set I have still has tons of life, I was planning on making a number of brake upgrades anyway, so I decided to pull the trigger early on these. The fronts weigh 20.8lbs, and the rears weigh 11.9lbs. For contrast, the DBA5000s weighed 22.4lbs and the stock 9 (320mm) rotors weighed about that as well. The rear DBA4000s weighed 14.8lbs, so it was about 3lbs of savings in each of the rear rotors.

Another difference between these rotors & the DBAs is that the DBAs were not directional, while these are. Girodisc clearly labeled on the box & the rotors themselves with tags which rotor goes where. Directionally vaned rotors act as centrifugal pump to pump out the hot air that passes through them, which makes more sense to me than non-directional. The DBAs tout a kangaroo paw design that works more as a vent than a pump. In reality, both rotors will likely see & get up to similar heat levels. The fronts come with about 32.4mm of thickness, and the rears come with roughly 22. The minimum thickness levels are 30mm and 20mm respectively. The DBAs that were on the car had 21.75mm in the rear.

In addition to the new rotors, I got new ST43 pads for the the fronts, with new titanium shims. The rears are interesting; they require the outside pad to be arced slightly, as to not make contact with the inner hat on the rears. I guess the rears don’t have a ton of clearance room, so there’s not a lot of ability to make the top hat smaller than it is. I decided to pair new pads with the new rotors to eliminate any sort of uneven wear situation.

I got them bedded in nicely and they feel great. Looking forward to running them at autox and the new few track events!