M3the01

I would still weigh them and move on to PFC.

pridanc

I've been a "lurking" forum reader for years and have really enjoyed the braking-banter here. I realize that most of us share our experiences as our own personal facts so to speak so no one can argue that person’s personal experiences right? At the same time, we all seem to be acknowledging that none of us are operating in a perfect vacuum which can bring about different results than others have found or experienced. I love what goes on here and also like that everyone is respectful. After so many years of silence I've decided to add my .02c. Note, this is long as I tend to ramble. I'll claim age...

So here I am, yet another track person who was blessed to have been involved with many things track related. One such related thing was to have spent a lot of time testing brake components on the track. I was even around when carbon brakes began making their way into the hands of us regular racing folk which was both a blessing and a curse. (frankly some of it was awful but I learned a lot and we all lived through it even if I did breathe/swallow a metric ton of carbon particles most of which came back up for days after each test)

There are many wonderful points being made here and I wanted to toss out some additional thoughts to consider as well. My words aren’t meant to say “this is right” or that “the other is wrong”, not at all, but more the sharing of observations I have lived and personally experienced.

Let’s first discuss Iron rotors. It is hard to beat them when using price as a significant part of your rotor-choice equation. Iron rotors are generally very robust with many options and manufacturers out there to choose from. Like anything, temperature rejection is a very important part of the rotor design and with that will come weight of the rotor. This mass (of the rotor) goes a long way towards helping the rotor and pad deal with the heat by moving that heat away from the rotor friction surface. Too this consider that you’ll also find a quite the choice of brake pads for the iron rotors as well. BTW it has been my experience that pad choice is a very important part when choosing brake components. Along those thoughts might I suggest that if you have the opportunity to take several different pad compounds out and test them back to back. Doing so will give you direct feedback as to how each behave from which you might find the one! (perhaps it best you ask the various pad manufacturer’s suggestions of pads they feel would fit your needs and go from there) Given the opportunity finding the pad that suits you make a difference. I don't say this lightly.

On occasion I hear that so-and-so’s brakes lack feel (iron or carbon) or some other related comment. Not to tread on anyone but I can guarantee you that the person who originally tested and recommended that pad/rotor combination didn’t feel that way! I want everyone to understand that most brake feel comes from the pad itself. (Yes, there are other factors that affect brake feel but the pad was number one for this in my lifetime.) Lets wrap this up: Each of us looks for our own particular feel (behavior) of the braking event all of which really means there is no single pad that fits us all.

The best example I can give is of myself vs. one of my well-known teammates as I never liked his choice of pads. The initial bite and torque given vs. heat and pedal pressure did not suit me no matter how you sliced it. If I had to describe it my feet were not as sensitive as my teammate, so I had to have a much lazier pad or I was useless. Was he right? Was I? Neither of us were right accept to ourselves. And by the way, the engineers were happy with both of us as there was no measurable lap time loss on-track because of our personal braking choices.

Now I’ll look at Carbon Ceramic rotors (CC moving forward). Not having read every brake comment embedded in this huge forum, I may need to first mention that there is a pure-carbon rotor/pad combination that is common in full-on racing cars. I am not talking about those rotors/brakes. I am only discussing the more prevalent and common CC rotors we see today on many of our street/track cars. There are real measurable benefits to be found by using these amazingly lightweight rotors but as we know those first carbon rotors, the all-carbon ones, were not a good fit for the street with the most glaring fault being their poor cold temp stopping ability. As in none. Until warm a carbon-carbon brake did so little you would have had more success dragging your foot. Because of this the brake manufacturers began a search for a lightweight alternative which is how we are now using the carbon-ceramic mix so common today.

I’m also going to say that when I first tested carbon brakes back in the day, those rotors were also built up in varying manors just as we see in the various CC rotors today.

As the streetcar manufacturers lined up for these newfangled CC rotors, it became obvious that there would need to be a way to create rotors in a less costly manor which led to them using short chopped-fiber bits of carbon compressed and “cooked” which became the de-facto most common method of manufacture. (it is more complicated than my few words here but for this discussion lets run with it)

As far as I can see the only true downside to this method of manufacturing is found (only?) at the track because they lack heat control. As good as these common short-fiber CC brakes are, excessive heat will shorten their lives considerably. (anyone who has tracked their car using the common OE supplied CC rotors can attest to right?) We now realize that once the rotor surpasses a certain temperature their life falls away at an alarming rate but remember, and this is a huge, in the street-car environment for which they were designed they are golden. Long life was found with these new CC rotors over iron and to add to that there are some wonderful additional benefits the greatest which is the weight savings.

Not only did un-sprung weight go down, (simplistically this meant it was easier to keep the tire on the ground under all but the worst of times), the rotational weight went down making the car lighter as well. These are huge considerations when we note that most manufacturers are constantly looking for ways to achieve those very things and all they had to do was to bolt on carbon-based rotors.

Finally, all else being equal, a car is always quicker around the track with carbon-based rotors. (the take away here is "all things being equal")

Let’s get back to the discussion of tracking our cars with the standard CC based brakes vs iron. There is always a discussion of the cost differential but I say we should consider the ROI before drawing a line in the sand which can be a difficult comparison partially brought on by the choices of iron/CC brake fitments and expected brake performance.

The best iron rotors (my version of best means lowest Moment Of Inertia in the rotors made to do the job I have in mind combined with the greatest bite from pads whose feel I prefer) are not inexpensive but it is my firm belief that when you use the enhanced performance found in the CC brake as part of your ROI equation then the scales close up. (my scale is not your scale so in my book the ROI closes up or should I say evens out a bit? Ultimately this is for you to say) Which brings us full circle to the track.

If the common short-fiber CC rotor was not good at dealing with the extreme heat of the track, then what was next? Suddenly the long-fiber carbon-ceramic rotor comes into existence in the CC world. The commonly fit OE short-fiber rotors are simply remarkable on the street where the rotor temperatures rarely if ever reach the destructive area for this type construction but when they do get damaged they have to be thrown out as these short-fiber rotors are not resurfaceable. Consequently, any effort to justify the typical short-fiber rotor to the iron rotor in any kind of ROI comparison you'll find the short-fiber rotors take a beating.

Meanwhile some folks in the UK concluded that strength of a long-fiber could be superior and more importantly heat control/dissipation would be as well all of which has proven to be. Strength for example (and I know this is over simplistic) but go get a piece of particle board and a short equal-thickness piece of wood. The particle board we will call short-fiber, the piece of wood we will call the long-fiber. Now try to break them.

And heat? Best example I can offer up is this: If you were to pick up a length of aluminum rod (really anything that conducts heat) and put a heat source to one end of the rod while holding the other end with your hand. Before long you’d feel the heat that has moved through the rod. Now take two rods that end-to-end are longer than the single piece rod but when laid parallel (not touching) and adjusted their overlap until their combined length is the same overall length as the single rod. Put the heat source to the far end of one of the pair of rods and hold the far end of the second rod. You will notice that it takes longer to feel the heat as the heat will have to migrate through the first rod, across the gap where they overlap, and through the second rod to your hand. Overly simplistic but I use it as an example to paint a picture.

As subsequent testing proved they were correct on both counts so they could now make CC rotors that worked just as well on the street as short-fiber rotors did but that their long-fiber construction withstood much more heat on the track and now seen as a giant improvement. As luck would have it these guys discovered long-fiber rotors could be resurfaced just like an iron rotor further adding to their long life and potentially the ROI. (this is not resurfacing by adding material, but simply cutting the faces as you would an iron rotor thus removing some small portion of the rotor) Let's not forget that the traditional short-fiber rotors tend to rely on two measurements pointing to their need for replacement. Weight and/or thickness. Since the long fiber rotor is so adept at moving heat, weight isn’t a part of the equation. When I used to be more heavily involved with driving and testing, I knew of several different rotor manufacturers. Today I do not know all folks who still make them but let’s not forget that Brembo own the lions share of the high-performance brake market. Thus, when looking for rotors, know that most rotors out there are Brembo (even if branded something else) and most often are short-fiber.

Pads: As we discussed early on, the pad choices are quite large for the iron rotors and it is important to find one that suits you. Today there are not as many pad options for the CC rotor however more pad choices are coming as the CC market continues to grow. The added life and heat control of the long-fiber rotor allows a more aggressive pad than the short fiber rotor all of which point to the fact that your pad choices are opening up. I know for a fact that there are other brands testing/formulating pads now for CC use.

My final .02c? Figure out what you want out of your brakes as there is a match to your choices. And if you like to track your car don’t let the initial purchase price of the more affordable long-fiber rotors in your “do I or do I not” calculations when considering ROI of the potential choices. The long fiber rotors live so long (they are resurfaceable remember?) suddenly the buy-in price becomes less of a factor. No question the retail pricing of iron rotors is the lowest followed by all the rest of the CC alternatives. (discounts and deals don’t count in my words above)

Make your choice using the factors that fit your needs. There are great brake choices out there but the “scale” you use to make your choice is all up to you. What works for me may not jive with what works for you. As technology moves forward, there is no longer a reason to forego the CC rotors because of life as their on-track behavior is amazing due to the long-fiber rotors out there.

I hope I have not muddied the waters too much as my intent was to share my past experience and knowledge all in an effort to help you define your own choice. Moving forward I will continue to “lurk” and will continue to read everyone’s experiences here and will opine if I feel I can add something to the discussion. Now get out there and enjoy your cars and please continue to share your experiences. I’m sure there are many others besides me who simply love to read about it all.

LSs1Power

Thank you pridanc for explaining the difference between short and long fiber CC.
I track my car 2-3 times a year but I usually push 100% when doing so. What i do mostly with my cars are canyon driving which doesn’t push the brakes like BIC for sure.

From your experience, what pads do you recommend with Surface Transforms Rotors?

Here is a picture from last event that fried the Brakes. This is at corner one coming down from 175mph to 30mph at corner one. BIC has three other straights after this one 🤦🏻‍♂️

M3the01

Surface transform w/ pagid RSL-1 are really amazing but only available from auto quest I believe. They bite harder but leave a lot of material on the rotor so actually decreases rotor wear. Also nice is the bite when cold, amazing. They are noisy though but I don't mind.

For the OP, wow, now I can clearly see how ur brakes were cooked.

rcg412

agreed, 175 -> 30. That’s some serious braking!!!

MaxLTV

Wow, this is very strange. I wonder if it's track-specific or some sort of a defect. There are many people tracking with PCCBs without any such issues.

It could be (I'm just speculating here) that PCCB rotors just fall apart once they reach a certain surface temperature, so basically even one very long brake zone could do it, but they are fine with sustained high temps below that level. That would explain how some are getting a lot of life out of them while others are not.

LSs1Power

I have seen others driving their GT2RS on BIC, they are 3-4 seconds slower than what im doing so for sure not pushing hard enough. That explains why other have long life on the brakes.

i think the solution could be larger brake cooling hats for better heat management at tracks such as BIC. It seems i will go with ST rotors if Porsche still insist on not covering my brakes under warranty due to cooling deficiencies flaw within the system.

M3the01

I would go PFC, they utilize in cup cars, proven performance... i run the ST brakes and RSL-1s but i think, even with the 100 degree cooler running temps, u likely will still be in for issues. Keep us in the loop.

thuggo

I mean this is your problem right here.....PCCB's aren't meant for that type of prolonged abuse. Porsche Track crew in Alabama swap the rotors once a year....and thats a crap load of track days on those rotors.

ddugas01

I never liked those yellow calipers.

pridanc

Folks, RSL-1 pads are available from several of the known "racing stuff" outlets in the USA. If you go to this Pagid dealer locator link, enter the USA as the country in our case, you will be taken to a page showing those here who carry the product like the RSL-1. Familiar places like Hoerr Racing Products, Paragon Products, Northstar Motorsport etc. (this is me naming a few I've dealt with but not the full list as there are more locations out there.

JBurer

Surface Transforms works with Autoquest and HCF according to their website:
https://surfacetransforms.com/distributors#USNA

pridanc

All brakes glow when used hard which I absolutely love. Of course like anything that admits light it helps when the ambient light is not so much. I used to hang out at the high speed to slowest corner observation areas during evening to night practice to get the best pictures. Ironically you could actually see that a difference in glow meant that there was a brake-use differential and might ought to be addressed (for longer life and sometime better braking performance) Clearly an equal glow usually happens when the car is balanced/still balanced and getting the discs to glow similarly can't / won't always happen.

As far as Pagid pads, It comes down to personal preference as most brake pads have their own unique feel and behaviour as mentioned. However that said I believe that the RSL 1 pad is the best for track use. Based on the performance numbers taken from the brake dyno, the RSC1 would be a good street/track compromise. I know too that some well known folks in the Porsche world swear by the PFC-11 with the ST rotor for both feel and rotor longevity. IMO, and this is just a guess, it still comes down to what you personally are looking for in a Pad / pad-feel.

M3the01

I didnt have any luck sourcing and Pagid for rsl-1s for the gt series yellow calipers and they sent me to Autoquest, seems like they control the rsl-1s for the ppcbs.

pridanc

LSs1Power, I thought I'd replied to this yesterday but I don't see that reply so I apologize. Feel free to reach out to Pagid but I recall the RSL-1 as their suggested track pad for the ST rotors with RSC-1 pads being a good street-track pad. I also have friends who love the PFC11 pad on the ST rotor but you will get tires of hearing me sayo "find the pads with the feel you like and stick with it." Sometimes there will be other circumstances that might push one pad higher on your list than another such as life of the pad, but I harp...Find the pad that fits your needs. Have fun!