nolimits

Any comments on how well Girodisc rotors worked on track vs OEM PCCBs ? Stopping power same or lesser due to less swept area? What pads did you use and were they quiet, street worthy too? I like the PCCB stopping capability and lack of noise but am weighing the cost/performance issue. Giros less of course. I'm assuming aggressive pads could offset less Giro swept area and thus stop similar, but would be noisy on street. Want to keep OEM PCCB calipers. Any input appreciated, lap data differences especially if you have any. Thanks

Randyc151

Girodisc rotors combined with Ferrodo DS1.11 pads are different in feel from PCCB and stock pads, but the overall effect is a wash on lap times. The OEM pads have a harder initial bite, the Ferrodo's are more constant. Both feel brilliant, both give me similar lap times. I found the Ferrodo's have a bit of squeal for the first few hundred miles until they are truly bedded, but after the rotors are really set there is very little brake noise at all on the street. After a track event, if they do have some noise, I use a power washer to spray into the calipers to clean out any dust and it clears any remaining squeal or grinding sounds. Overall, the risk of killing a set of rotors (at $5600 per rotor) is not worth it to me, and the Girodisc/Ferrodo combo is every bit the equal. I'm putting that setup on my GT2 RS before the first track event in March, without hesitation. If you have questions, contact Clarke at Apex Performance and get ready to hear an expert at work.

nolimits

Sounds good, will probably get a new set of pccb to store, and get Giro for use til any sale. I see 2rs ADMs coming down, vodoo 2rs tempting if possible. If I can get TTS to keep up with 2rs I'd be happy, need to do a little power work to get there, suspension tires good.
Any like new Giros out there ?

wirx

What about 20" 265 CUP2 R front and 325 CUP2 Mercedes rear?
Is it safe for 4 wheel drive considering different models of tires?

Randyc151

I've thought about that combination, but ultimately decided that it's possible it would be too unbalanced. I don't think it would hurt the 4WD, but without the same rear traction, I think you loose any benefits of the better front grip with more understeer as you wrap the corner. But hey, give it a try and report back!!

Need4S

euromotiv

Hey guys, i recently started going to the track and been there three times. Im going to do my brakes with oem pads/rotors but was wondering about the fluid. Should i do a flush or just keep whats in there. If so what fluid do you recommend, the oem?

Need4S

Jean

Need4S

The extreme heat cycles of track driving tend to induce absorption of moisture into the brake fluid. If you've already tracked the car 3x and not changed the fluid, I suggest you do a flush. I use Motul RB600. Some use RB660 or Castrol SRF, but any high temp fluid will likely be fine. Look for high wet as well as high dry boiling points, esp. if your car is also street driven and you don't flush the fluid after every track day or only once a year.

OEM pads and rotors are fine, but some tracks are harder on brakes than others. If you have OEM iron rotors (turbo, instead of turbo S), you might consider GIrodisc rotors and higher temp range pads. As with anything else, there are tradeoffs - higher heat range for pads can mean insufficient low temp bite for street driving, and/or noisy brakes. I still run OEM pads with my iron rotors but am contemplating going to Ferodo DS2500 or Porterfield R4-S next time. If StopTech Sport Pads were available, I'd consider those as in-between the Ferodos and Porterfields, but last I looked they aren't available in pad backplates that fit 991 turbos.

Randyc151

Just use Castrol React SRF. It's probably overkill, but don't think twice about it.

GT2Driver

Randy you got PM

miky360

What kind of camber are you guys running? Just did my first track day with the car and im rolling on the sidewall quite a bit. Im on Pilot Super Sports but switching to Trofeo R’s in June.

Jean

Roll is more likely to do with high tire pressures and toe rather than camber. For these tires if you can run -1.5 deg front and a bit less in the rear you should be set.

Randyc151

It's time for everyone to provide mid-season reports! For me, I have 8 track days on the GT2RS, and it's simply stellar. I added a half-cage and used the Schroth 4-pt harnesses designed for the factory buckets. They work great - more comfort, zero negatives. I took the car up to TPC Racing for a track alignment and settings, and Mike Levitas consulted with Manthey and Lars Kern regarding their optimal setup...which we went with. I'm still getting some lift on the back straight hill crest at VIR when coming over the hill above 165, so we may lower the front a bit for safety. The GT2RS is hitting 175+ at the end of the back straight on good laps, compared to the occasional 170 on the TTS, but the Cup 2R should help with entry speed and I think I could see 180 in cool Fall weather. As for times, the GT2RS is about 2 seconds faster so far than the TTS, but I still have more learning to do regarding downforce and trusting the car. I also have to decide how far I'm willing to take this car towards the limits, and I'm not sure I have the ***** to go to the edge in a car this fast and expensive. Track insurance is $1900 per weekend, but I still have it in the back of my mind that I'm better off turning 2:00 flat than 1:58 and really taking a risk.

I'm still on the factory Cup2 tires, very good but similar grip to those I was running on the TTS. No doubt, the 2R tires will be next. I got Randy Pobst in the car with me at VIR for some data collection and hot laps, and he took the car 2 seconds faster than I have at VIR, but said the 2R tires would be good for another 5 (!!) seconds at VIR. Otherwise, besides tires, I'm waiting for DSC Sport to get the programming done for the V3 box to work with front axle lift, and get than installed. On track, it's stupid how many people want to give very late passes, either from fear or hubrice, but the car does have a huge target. For the record, I've given 1 point-by so far, to a 991 Cup car on race slicks. I think he was about 4 seconds a lap faster than me.

I've returned my TTS to full OEM and it's passed CPO inspection. It is in absolutely perfect condition, down to the unused seats and floor mats. It's on the dealer's lot, but few offers so far, and the dealer that has it on consignment says they have not seen traffic this slow in a few years, so it's not a great time to be on the market. I'm not desperate, so I'll continue to hold out for a reasonable price.

What new things have you guys learned about or tried this season?