GoatHead

17' GS with iron rotors and Brembo calibers.
I have been using the stock iron rotors with Carbotech XP12 and XP10 for 3 HPDE events all of them on VIR full course. The rotors started to show cracks, and I probably can get one more event out of them. The front Pads has 1 or perhaps 2 events on them left.

I like Carbotech, because they are compatible with their street pads. So, I don't have to bed them before each event.

I am looking for recommendations for Rotors and perhaps Pads. Longevity and cost is important to keep the cost of consumable down.

I know the options are Stock rotors, DBA, and GiroDisk. Anything else out their? What is your recommendations.

Thanks,

KNSBrakes

We have DBA discs in stock should you go that way.

We also have the first set of Girodisc replacement only discs (like the DBA rotors) They are front only fitment.

-Ken

RapidC84B

OEM or DBA 2-part rotors and Carbotech or Glock pads 12 front 10s rear.

GoatHead

I sent you a PM

Floridamark

I run this and like this setup a lot.

https://www.girodisc.com/Rotors-_c_1343.html

With:

Carbotech™ XP12™

Another highly successful XP™ series compound with an excellent initial bite, torque and fade resistance over and above the XP10™ compound. XP12™ has temperature range of 250°F to 1850°F+ (121°C to 1010°C+). The XP12™ has that excellent Carbotech™ release and modulation that has made all other Carbotech™ compounds so successful. The XP12™ is more rotor aggressive than XP10™, but compared to the competition the XP12™ is still very rotor friendly. XP12™ is NOT recommended for use as a daily driven street pad due to possible elevated levels of dust and noise.

Carbotech™ XP10™

When Carbotech™ unleashed the XP10™ to the general public it immediately gathered multiple regional, divisional, and national championships. The XP10™ has a very strong initial bite with a coefficient of friction and rotor friendliness unmatched in the industry. Fade resistance is in excess of 1475°F (801°C). XP10™ still maintains the highly praised release, excellent modulation and rotor friendliness that have made all Carbotech™ compounds so successful. Carbotech™ XP10™ is not recommended as a daily-driven street pad due to possible elevated levels of dust and noise.

taken19

You can’t go wrong with the DBA rotors and Carbotech pads. I did notice on my old GS that the 12/10 combo seemed to get the rear wheels into ABS more than I would like to see. It might be worth considering dropping down to 12/8 or something similar. The XP10 compound may be a bit aggressive for the rear based on the amount of weight on that axle under threshold braking...

The 12/10 combo certainly works, don’t get me wrong. I’m just wondering is there’s a slightly less aggressive pad out back that would bring the system back into equilibrium (or as close as possible).

Food for thought...

GoatHead

Thanks for the insight. I haven't noticed ABS intervention, but I may not be braking hard enough. I still have good meat on the rear pads, so I am going to use them until they are gone.

How many track session do you usually get on DBA rotors?

GoatHead

How many track sessions do you usually get with Girodisc?

GoatHead

Do you trust G-Loc over Carbotech? They maybe the same people, but do they have the same quality control?

The HACK

So, this MIGHT sound counter intuitive, but you might want to consider going to 12/12 instead of 12/8.

Hear me out.

When you have a huge brake bias disparity, you might end up locking up the rears because the fronts do so much work to slow down the car that the weight shifts dramatically up front on a heavy braking zone, making the rear tires lose traction and lock up quicker. On a car with more balanced braking you might actually get the reverse effect, where the front and rear are doing equal work without as much squat, the rears stay on the ground more and has more grip to slow the car down.

I know, counter intuitive. On a stock ABS and electronic brake bias, it’s oky to run a less aggressive compound in the rear, but when there’s too much bias weird stuff can happen.

Bill Dearborn

Take some pictures of your rotors that show the cracks you are talking about and post them here. You may not need to change just yet. The rotors will heat check and get small cracks in them. The heat checks will eventually lead to large cracks but usually you can get a few more days on the rotors if you have small heat checks.

Bill

GoatHead

Hi Bill:

It was a pleasure to meet you last weekend, and thanks again for all of the help you provided.
I will take a photo this weekend when I take the wheels off. I showed the rotors to my instructor (Mark) and he said I can get another weekend from them. I think it would be a good idea to have spare on hands just in case.

RapidC84B

Been racing and tracking these cars for nearly 20 years, using Carbotechs for 10+... never had tears get into ABS with 10s... ever.

RapidC84B

Yes... just made the switch and bought 3 sets. A few race buddies have been on them a couple years now w/o issue.

GoatHead

If you don't mind me asking: Why did switch from Carbotech to GLoc? Was it cost or quality?

RapidC84B

I raced a C5 in ST2 with NASA for a couple of years with some success. Some of the guys I raced very closely with made the switch a couple of years ago and like them. The folks who run TMI at VIR (the paddock shop) stock them now and the owner of G-Loc reached out to me as he's trying to grow C7 market share. And yes... they're a little cheaper than Carbotechs. I have nothing against Carbotech and have been a vocal user of their products for a long time; probably 10 years now.

Bullet Tooth

I am interested in the DBA v. Girodisc rotors as well. My iron rotors will need to be replaced soon and I have no experience with either. DBA are clearly less expensive and Girodisc are apparently lighter. I do not mind paying a bit more, but I am most curious about longevity and performance.

Good thread Goathead.

RapidC84B

I've never run DBA on my C7, but they're about to go on (sitting on the shelf in the garage now). I ran their 2-piece non-floating setup on my C5 racecar and rotors would last an entire race season. Was very happy with them coming from running solid NAPA blanks that would crack after a weekend or two.

GoatHead

If you have DBA rings, could you please post the part numbers? It is very confusing and I can't find a reliable resource.

Thanks,

GoatHead

GiroDisc is actually cheaper than DBA. DBA Rings are $738 and GiroDisc rings are $700. Right now, you can buy GiroDisc with hats, but you can't buy DBA with hats. DBA support doesn't exist. They don't respond to emails and the tech and customer service numbers listed on their website are spam numbers - recorded message asking to buy a $50 gift card for $1.