summit81

I am very pleased with GiroDisc rotors. After 22 track days, I am on my third set of Pagid RS29 up front, and second set of RS 14 on rear (first set rear were RS 29). The front rotors are more worn than the rear, and the fronts show superficial surface cracks from heat. The cracking is not through the entire rotor thickness, and I suspect that they will reach minimum thickness before cracking through. There is no grooving in the rotor surface and no warping. The braking is still silky smooth cold and hot, on and off the track. I spent four consecutive days (10 hours) at Summit point last week in 105 degree F, and the rotors and pads held up just fine. I would say that is a pretty compelling test for these rotors.

I need to take a measurement of the rotor thickness on the front, but just by eyeballing I hope to get at least another six track days out of the fronts. We'll see. The rears are going to last considerably longer.

Another thing I like about GiroDisc is that they are bigger than stock but they probably weigh a little less. The kit comes with longer caliper bolts and spacers.

The GiroDisc is not the least expensive rotor, but I believe they may offer the best longevity, so they may offer the best value. Because these are so durable, I don't have to change the rotors as frequently which further justifies the price.

(Based on my personal experience and what TRD0524 says about Pagid vs PFC, I do not plan to switch to PFC. I am sure the PFCs are great, but the Pagids work wonderfully and are very gentle to the rotors. Try running PFC for 10 hours in 105 degree heat and see how long the pads last and what they do to your rotors. I do not mean to disparage the PFC pads, but I just want to give my endorsement for Pagids. Bedding in is also very easy on the way to the track. I perform 10 stops with medium brake pressure from 70 to 40 mph, and then 4 hard stops from 75 to 40 with the 2-3 light stops in between the heavy stops. That is it. Pagid has a very specific bed in procedure that is impossible to do under the speed limit on public roads, but their procedure is not the only manner in which the pads can be bedded and seasoned. The idea is to get some heat in the pads during bed in, but not to over heat them. It takes me about five minutes to bed the Pagids, and by the time I am at the track they are ready for a full, hard session. With the bed in procedure that I described, I do not have any squealing with the RS 29 or RS 14, and I do not bother beveling the leading and trailing edges of the pads. )

summit81

Pictures of GiroDisc rotors after 22 days on the track on a 2011 997.2 C2S. Front rotors are at the limit of 32mm thickness and have surface cracks but no grooves. Notice also that the disc has worn past the slot in some areas. Time for new front rotors. Rear rotors have no cracks and also no grooves. Thickness of rear rotors is 27.6mm. The limit for the rear rotors are 26mm. Pads used on these rotors are Porsche OEM for street and Pagid RS29 for track use.

Obviously the front rotors get very hot compared to the rear. I have changed to Pagid RS14 compound for the rear, but honestly I do not notice a difference. I will likely stick to the RS29 compound all around because of the endurance of this compound and because they are not hard on the rotors.

ir_fuel

22 trackdays??!!!

Either you brake like a little girl or these disks are serious business

Nice

Izzone

We get 20ish days out of PFC slotted rotors

But I try to brake less

mdrums

Summit, thanks for the pics. I wish Giro Disc would make the GT3 center section they make but fit the smaller rotor we use. My GTS is a center lock car and Giro Disc doesn't make a front or rear rotor for GTS cars. I've emailed them about this too but they do not seem interested.

mdrums

or the track he is on is not hard on brakes. Most all my track events are Sebring. Pagid RS29 Yellows last me around 6-8 days and that is pushing them past my comfort level of pad thickness. 5-6 days and they really are at around 35-30% left pad material and they start to transfer heat to the caliper.

summit81

That probably is true. My home track is Summit Point where I tend to spend about 1/3 time on Shenandoah Circuit and 2/3 time on SP Main. I notice considerable more brake wear when I am at VIR, presumably because of the greater overall speed although SP Main speeds at the end of the front strait is comparable to the long straight at VIR.

Two weeks ago I was on SP Main for 10 hours over four days, and the first four hours were in 105F temps. I was very impressed with all of the braking components -- Motul 600, GiroDisc, and Pagid. No issues whatsoever.

ir_fuel

So far I got 0.5 days on my PFC rotors, dimpled.

Ajjra

Just got them installed with Pagid RS-29's at all 4 corners. Stock rotors in rear. Pretty wobbly feeling before the proper bed in procedures for the rotor and pads. I feel like I can hear the rotors clicking too when income off the brakes. Is that my imagination.

mdrums

Ajjra, the Pagid race pad all click that is normal. They will click sometimes and they will squeal and make horrible noise when braking too....that is one reason why race pads (shape and compound) are not stock items in street cars. General public wants quiet operation....racers need a pad that works at temps never seen on the street.

summit81

Hi Ajjra,

I am unsure what you mean by wobbly feeling, but I will offer my experience.

I bedded in the rotors exactly as GiroDisc describes (http://www.girodisc.com/assets/image...onfloating.pdf). The instructions state:

• Drive the vehicle cautiously a short distance to test fit and function. The brakes should be smooth, with no vibrations, judder, etc.

And this was my experience. The rotors were silky smooth brand new (and still are), but one can and probably will get judder occasionally even if you follow the bed-in procedure exactly. Brake judder feels like something is very wrong -- like the rotors are warped, but this is not the case. Judder is caused by an uneven buildup of brake material on the disc. I have had it about three times in the life of my GiroDisc rotors. The last time I had it was the first track session after bedding in a new set of Pagids. During bed-in, there was no judder, but during that first session the judder gradually increased. The vibration was so bad that I had to leave the track, thinking that I may have installed the pads incorrectly or that I forgot to torque the wheel bolts. Each time I have had judder, I drove off track and performed several long, easy stops. I do know whether this is useful or necessary, but I felt that it helped clean the rotor surface. In any case, the judder is very temporary and after about 20 minutes on the track will end and not return thereafter.

The new GiroDisc rotors bed-in procedure is not the same as the Pagid bed-in. I was careful not to introduce too much heat too fast into the new rotors. "The purpose of this procedure is to gradually increase the temperature in the components without inducing thermal shock, and to mate the brake pad and disc friction surfaces." After rotor bed-in, there is no need to ever worry about the rotors.

In my experience, the Pagid bed-in is not critical so long as you do not put too much heat into the pads too fast, and then allow them to cool. (see my bed-in procedure here). The Pagid bed-in is more aggressive (higher temps) than rotor bed-in. At least that is my interpretation of the instructions for each product, and how I went about it.

I hope this helps. If not, call Stuttgart Performance and talk to Anthony (or Antony?) or Mike. They are always very helpful and accessible.

fc-racer

My Giros click too; I asked the very same question after getting them installed. Mine also make noises when cornering (I think; to be verified). Braking performance with the PFC08 and Giros is mind-altering. I need to re-learn how to brake, but even with sloppy driving, I'm beating my PBs by a few tenths.

Ajjra

What about clicking sounds at Highway speeds?

mdrums

No I don't get that...just clicking at slow speeds, stop and go like in a parking lot.

Ajjra

I have the sound as well. That's no big deal. This sounds sort of like that but happens at 55mph even when not breaking.