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I didn't want to start a new thread, so hopefully someone here can answer my question. I recently took delivery of my 2022 718 GT4 and noticed that the rear pads have very little surface area in contact with the rotor. See picture below. Does this look normal? I only ask, because I've been a bit underwhelmed in the braking performance, and am researching my options. Does the pad surface area vary with aftermarket pad options?
As for being underwhelmed by the brake performance, I'd have to agree. With track use I found I likely exceeded the heat range of the OE pads as the pads performed inconsistently (started blowing the corner off the main straight as braking distances started increasing). I am pretty sure I glazed my pads as initial bite on the street is worse than when I drive cold race pads on the street and I noticed the next track day the brakes felt like crap for a long time, like I had half braking power and that took around 3 laps to fix.
I'm going to run these pads until they're worn out but I'm looking at something more aggressive for track use for my next pad as I don't think the OE pads are a good fit.
If you're fast enough the OEM pads fall apart long before they wear down. After 4 track days for me the bonding agent melted and left these really bad deposits on my rotors which started causing horrendous brake shudder. Once the OEM pads have been pushed to that point they literally start to fall apart. It's actually kinda dangerous to be honest.
What are the aftermarket solutions for converting to carbon ceramic brakes? I'd like low/no dust, and still be able to use them on the track once a year. Is this possible without spending $30k?
Yes, Surface Transforms CCM rotors. Last substantially longer than OE PCCB rotors at roughly half the cost. You can also get them refurbished up to 4 times throughout their life. If you only track the car a few times a year and the rest is street driving, you won't ever have to replace your rotors again. They have two options: an "Upgrade" Kit, and a "Replacement" kit. The "Upgrade" kits are for OE iron calipers. The "Replacement" kits are for OE PCCB calipers. Pricing is the same for both, at $6957.50 per axle ($13915 per car).
Contact me for the best pricing. You can learn more about them at the link below as well or call/text/email.
Yes, Surface Transforms CCM rotors. Last substantially longer than OE PCCB rotors at roughly half the cost. You can also get them refurbished up to 4 times throughout their life. If you only track the car a few times a year and the rest is street driving, you won't ever have to replace your rotors again. They have two options: an "Upgrade" Kit, and a "Replacement" kit. The "Upgrade" kits are for OE iron calipers. The "Replacement" kits are for OE PCCB calipers. Pricing is the same for both, at $6957.50 per axle ($13915 per car).
Contact me for the best pricing. You can learn more about them at the link below as well or call/text/email.
I am very keen to get some solid data on the lifecycle costs of cast Iron discs vs surface transforms. We know that PCCB are not economical compared to iron discs for people who do lots of track days but ST's change the game in a big way.
If we get 20 track days out of a set of iron rotors and they cost $2500 for a set, how many days can we expect to get out of a set of ST's before they need to be refurbished? Refurbishment is $600 per rotor so that's another thing to add into the economics. It's very hard to compare driver to driver so would be great to see people who have experience with both.
My Iron discs will be up for replacement next year so that will be a decision point for me on whether I get another set, or take the plunge on ST's. If they end up saving money over a 5-10 year lifespan then I will do it but at a minimum they need to last at least twice as long as a set of iron discs between refurbishments before the economics even start to make sense.
They say 4-5000 miles of track driving is their lifespan, some quick math on that.
If I typically have 200km/125 miles driven per track day on track, and a quoted 5000mile lifespan. That's 40 track days with 3 refurbishments along the way? Total cost of $13000 + $2400 x 3 is $20 000. I could do the same 40 track days with 2 sets of iron discs for $5000. So the pure economics simply don't stack up. If they can do 5000 track miles between refurbishments then the pendulum swings back the other day.
I guess it just reinforces the reasons why ceramics are banned from most motorsport categories. If they were genuinely more economic to run then iron discs then GT3 cars would use them for sure.
From what I can tell the most cost effective braking solution for track days is a set of 2 piece PFC rotors. $3800 up front and $1200 for a pair of replacement rings.
I am very keen to get some solid data on the lifecycle costs of cast Iron discs vs surface transforms. We know that PCCB are not economical compared to iron discs for people who do lots of track days but ST's change the game in a big way.
If we get 20 track days out of a set of iron rotors and they cost $2500 for a set, how many days can we expect to get out of a set of ST's before they need to be refurbished? Refurbishment is $600 per rotor so that's another thing to add into the economics. It's very hard to compare driver to driver so would be great to see people who have experience with both.
My Iron discs will be up for replacement next year so that will be a decision point for me on whether I get another set, or take the plunge on ST's. If they end up saving money over a 5-10 year lifespan then I will do it but at a minimum they need to last at least twice as long as a set of iron discs between refurbishments before the economics even start to make sense.
They say 4-5000 miles of track driving is their lifespan, some quick math on that.
If I typically have 200km/125 miles driven per track day on track, and a quoted 5000mile lifespan. That's 40 track days with 3 refurbishments along the way? Total cost of $13000 + $2400 x 3 is $20 000. I could do the same 40 track days with 2 sets of iron discs for $5000. So the pure economics simply don't stack up. If they can do 5000 track miles between refurbishments then the pendulum swings back the other day.
I guess it just reinforces the reasons why ceramics are banned from most motorsport categories. If they were genuinely more economic to run then iron discs then GT3 cars would use them for sure.
From what I can tell the most cost effective braking solution for track days is a set of 2 piece PFC rotors. $3800 up front and $1200 for a pair of replacement rings.
I have been pulling data together to better understand this myself. From what I am seeing, the numbers suggest that running the STs can actually be cheaper in the long run. Every situation is different: every driver and driving style is different, tracks are different, each vehicle application is a bit different, pad compound is different, etc.
Please note that all of this is in relation to hard miles driven on track. Drivers who only street drive their cars will essentially never have to change their rotors again. Drivers who both street and track their cars will see a significant jump in mileage estimates.
As of now, ST estimates 4000-5000 hard track miles before the first refurbishment is required. Most drivers will likely get more mileage than this. ST also claims that the mileage between refurbs will reduce slightly after each refurb. Thus, a rough guideline could look as such:
Min Max Cost
New - 4000 miles to 5000 miles - $13,915
Refurb 1 - 3750 miles to 4750 miles - $2400
Refurb 2 - 3500 miles to 4500 miles - $1200
Refurb 3 - 3250 miles to 4250 miles - $2400
Total 14500 milesto18500 miles - $19,915
Based on a conservative estimate of 14,500 track miles on a set of ST rotors, your cost of ownership comes out to roughly $1.37/track mile.
If we go on the high end, based on the chart above (wherein we expect drivers to get even more miles than this), the cost is $1.08/mile.
The average cost is $1.22/mile.
Using our Cayman S rental car as a data point which has a broad range of drivers in it from Professional to Novice, we can get ~10 track days out of a set of front 2-piece iron PFC rotors, and ~18 track days out of a set of rears. Using that information to go the same 14,500-mile distance on iron rotors we would need
9 sets of fronts: $1900+1120*8 = $10,860
5 Sets of rears: $1900+1120*4 = $6,380 Total: $17240 = $1.19/mile
None of this factors in how much longer your pads will last with ST rotors either. As those with PCCBs know, your pads last much longer than iron pads, and ST-paired pads go even further than PCCB. ST rotors also are not as sensitive to running your pads closer to the backing plate like PCCBs are. You will save on pad replacement costs as well which are substantial and not factored in the above breakdown.
You then have to consider the ST resale value along with the performance benefits from reducing your unsprung, rotating mass by upwards of 50+ lbs in certain applications compared to iron. Your car will handle better, stop better, and accelerate quicker. To top it all off, you won't have to deal with brake dust with most approved compounds.
Again, this all comes down to the information I have. If anyone has an experience with either their iron or ST rotors that are significantly different than what my experience/projections suggest, please chime in so we can have better data to pass around.
Last edited by Hinz Motorsport; 07-07-2022 at 04:33 PM.
I have been pulling data together to better understand this myself. From what I am seeing, the numbers suggest that running the STs can actually be cheaper in the long run. Every situation is different: every driver and driving style is different, tracks are different, each vehicle application is a bit different, pad compound is different, etc.
Please note that all of this is in relation to hard miles driven on track. Drivers who only street drive their cars will essentially never have to change their rotors again. Drivers who both street and track their cars will see a significant jump in mileage estimates.
As of now, ST estimates 4000-5000 hard track miles before the first refurbishment is required. Most drivers will likely get more mileage than this. ST also claims that the mileage between refurbs will reduce slightly after each refurb. Thus, a rough guideline could look as such:
Min Max Cost
New - 4000 miles to 5000 miles - $13,915
Refurb 1 - 3750 miles to 4750 miles - $2400
Refurb 2 - 3500 miles to 4500 miles - $1200
Refurb 3 - 3250 miles to 4250 miles - $2400
Total 14500 milesto18500 miles - $19,915
Based on a conservative estimate of 14,500 track miles on a set of ST rotors, your cost of ownership comes out to roughly $1.37/track mile.
If we go on the high end, based on the chart above (wherein we expect drivers to get even more miles than this), the cost is $1.08/mile.
The average cost is $1.22/mile.
Using our Cayman S rental car as a data point which has a broad range of drivers in it from Professional to Novice, we can get ~10 track days out of a set of front 2-piece iron PFC rotors, and ~18 track days out of a set of rears. Using that information to go the same 14,500-mile distance on iron rotors we would need
9 sets of fronts: $1900+1120*8 = $10,860
5 Sets of rears: $1900+1120*4 = $6,380 Total: $17240 = $1.19/mile
None of this factors in how much longer your pads will last with ST rotors either. As those with PCCBs know, your pads last much longer than iron pads, and ST-paired pads go even further than PCCB. ST rotors also are not as sensitive to running your pads closer to the backing plate like PCCBs are. You will save on pad replacement costs as well which are substantial and not factored in the above breakdown.
You then have to consider the ST resale value along with the performance benefits from reducing your unsprung, rotating mass by upwards of 50+ lbs in certain applications compared to iron. Your car will handle better, stop better, and accelerate quicker. To top it all off, you won't have to deal with brake dust with most approved compounds.
Again, this all comes down to the information I have. If anyone has an experience with either their iron or ST rotors that are significantly different than what my experience/projections suggest, please chime in so we can have better data to pass around.
Not bad. With Renn10 you can knock that down to $18,523.50 or $1.28 a mile, and $1.00 a mile best case. A GT4 running OEM rotors, and using your assumptions for rotor life, and assuming $650 a rotor would be $15,600 or $1.08 a mile.
That data can be manipulated though. I mean, I change my rotors on my race car with every pad change usually because the rotors are cheap, but I can also push my rotors on that car to 50+ race hours using very abrasive pads.
On all the street cars I tracked I usually averaged around 10 track days per set of front pads and would usually get 2-3 pad changes out of a rotor which is when I felt it was probably time to change them, not when I had to change them (but these were blanks or slotted, not drilled). 10 would be changing them far earlier than necessary on all those cars.
As Hinz said it really depends on the track/driver/car/conditions/pad/etc, especially when the time to change a rotor is highly subjective. I’m approaching killing off my first set of tires on my GT4 so have a while to go still before I change my first set of pads, but so far so good on rotors showing no signs of rotor wear. Hopefully they don’t do the drilled rotor thing and start cracking like crazy.
I have been pulling data together to better understand this myself. From what I am seeing, the numbers suggest that running the STs can actually be cheaper in the long run. Every situation is different: every driver and driving style is different, tracks are different, each vehicle application is a bit different, pad compound is different, etc.
Please note that all of this is in relation to hard miles driven on track. Drivers who only street drive their cars will essentially never have to change their rotors again. Drivers who both street and track their cars will see a significant jump in mileage estimates.
As of now, ST estimates 4000-5000 hard track miles before the first refurbishment is required. Most drivers will likely get more mileage than this. ST also claims that the mileage between refurbs will reduce slightly after each refurb. Thus, a rough guideline could look as such:
Min Max Cost
New - 4000 miles to 5000 miles - $13,915
Refurb 1 - 3750 miles to 4750 miles - $2400
Refurb 2 - 3500 miles to 4500 miles - $1200
Refurb 3 - 3250 miles to 4250 miles - $2400
Total 14500 milesto18500 miles - $19,915
Based on a conservative estimate of 14,500 track miles on a set of ST rotors, your cost of ownership comes out to roughly $1.37/track mile.
If we go on the high end, based on the chart above (wherein we expect drivers to get even more miles than this), the cost is $1.08/mile.
The average cost is $1.22/mile.
Using our Cayman S rental car as a data point which has a broad range of drivers in it from Professional to Novice, we can get ~10 track days out of a set of front 2-piece iron PFC rotors, and ~18 track days out of a set of rears. Using that information to go the same 14,500-mile distance on iron rotors we would need
9 sets of fronts: $1900+1120*8 = $10,860
5 Sets of rears: $1900+1120*4 = $6,380 Total: $17240 = $1.19/mile
None of this factors in how much longer your pads will last with ST rotors either. As those with PCCBs know, your pads last much longer than iron pads, and ST-paired pads go even further than PCCB. ST rotors also are not as sensitive to running your pads closer to the backing plate like PCCBs are. You will save on pad replacement costs as well which are substantial and not factored in the above breakdown.
You then have to consider the ST resale value along with the performance benefits from reducing your unsprung, rotating mass by upwards of 50+ lbs in certain applications compared to iron. Your car will handle better, stop better, and accelerate quicker. To top it all off, you won't have to deal with brake dust with most approved compounds.
Again, this all comes down to the information I have. If anyone has an experience with either their iron or ST rotors that are significantly different than what my experience/projections suggest, please chime in so we can have better data to pass around.
Mate this is exactly the kind of information I have been looking for so keep up the good work, and thankyou so much for sharing! I wasn't sure on whether or not pad wear was also reduced so that definitely helps!
I drive my car almost exclusively on track these days so my use case is at that particular end of the spectrum so being wise with consumables can potentially save me a lot of money.
That data can be manipulated though. I mean, I change my rotors on my race car with every pad change usually because the rotors are cheap, but I can also push my rotors on that car to 50+ race hours using very abrasive pads.
On all the street cars I tracked I usually averaged around 10 track days per set of front pads and would usually get 2-3 pad changes out of a rotor which is when I felt it was probably time to change them, not when I had to change them (but these were blanks or slotted, not drilled). 10 would be changing them far earlier than necessary on all those cars.
As Hinz said it really depends on the track/driver/car/conditions/pad/etc, especially when the time to change a rotor is highly subjective. I’m approaching killing off my first set of tires on my GT4 so have a while to go still before I change my first set of pads, but so far so good on rotors showing no signs of rotor wear. Hopefully they don’t do the drilled rotor thing and start cracking like crazy.
You are absolutely right regarding the data. I try to avoid making theoretical statements, but since the question was asked I hope my response sparks some experienced ST owners to chime in to help everyone out. For this example, I was working off of STs claims, my own experience, and information provided by the owners that I have talked to. Most of them haven't even had to refurbish their rotors yet.
The cost/mile estimates are really just that, estimates. However, I think we will find that these numbers are in the ballpark and could easily swing in STs favor. The example above suggests that even on the high side of costs, it comes out to like $29/track day extra for the STs (excluding a host of other factors). Is the performance gain worth it? I know folks that would pay a lot more than $29/event to go quicker and not have to deal with brake dust.
As mentioned, our best bet is to get some ST owners who have several refurbs or say, 10,000+ miles on a set of these rotors to chime in so we can update this properly.
Last edited by Hinz Motorsport; 07-08-2022 at 11:01 AM.
Here are a couple of additional pictures. As you can see, the pad surface that is in contact with the rotor is less than 1/2 of the total area of the actual pad size. There seems to be two tiers of pad material. The initial tier is much smaller that the base of the brake pads. I've never seen a pad design like this (with such extreme chamfers).
It appears to be a more exaggerated version of this general design.
These are the rear pads on my 2022 GT4 with chamfer
You are absolutely right regarding the data. I try to avoid making theoretical statements, but since the question was asked I hope my response sparks some experienced ST owners to chime in to help everyone out. For this example, I was working off of STs claims, my own experience, and information provided by the owners that I have talked to. Most of them haven't even had to refurbish their rotors yet.
The cost/mile estimates are really just that, estimates. However, I think we will find that these numbers are in the ballpark and could easily swing in STs favor. The example above suggests that even on the high side of costs, it comes out to like $29/track day extra for the STs (excluding a host of other factors). Is the performance gain worth it? I know folks that would pay a lot more than $29/event to go quicker and not have to deal with brake dust.
As mentioned, our best bet is to get some ST owners who have several refurbs or say, 10,000+ miles on a set of these rotors to chime in so we can update this properly.
Yep and when my OEM ones need to be replaced it is going to be very, very hard to look past ST's as a result.
I don't want to spend money to go faster, that arms race is a slippery slope to a money pit. But if I can go faster while spending LESS money overall then that's just a no brainer.
From what I am seeing, the numbers suggest that running the STs can actually be cheaper in the long run. Every situation is different: every driver and driving style is different, tracks are different, each vehicle application is a bit different, pad compound is different, etc.
I appreciate a bit of good marketing, and your disclaimer is absolutely valid. It is possible to engineer a possible use case where the ST aren't much more expensive. It just requires taking a manufacturer's endurance claims and comparing that to a rental cayman S (a car on smaller diameter discs and more brake cooling issues generally)
I track quite a lot, and I don't hang around, and my GT4 stock discs last me a season using DS1.11 pads. Aftermarket slotted discs are better in terms of longevity still, but I'm probably an outlier in efficient brake use and I avoid long stints where temperatures build up.
Even so, it's best case scenario vs worst case scenario. And I'm guessing that getting the ST discs resurfaced takes more than 5 mins as well in terms of scheduled downtime of your track car as they need to be shipped back and forth quite a distance.
If I had to guess I'd say the Surface Transforms discs will be about twice the cost to run of steels and they're worth it if you can afford them. There's no such thing as a free upgrade. If it's a lot better odds are you need to pay for the difference.
I have been talking to local workshops who support a lot of motorsport events and the numbers they are experiencing is that people who typically get 10 track days out of a set of iron discs have swapped to ST's and done 20 track days and counting with "no visible signs of wear".
They are yet to need to refurbish a set, and are predicting track focused people to get 5-7 times the life from ST's over iron rotors. If that's the case then they will have paid for themselves before you even need to refurbish them once.
My own personal experience with ST's is as pit crew for a friends GT2 RS that he races competitively and they have held up extremely well so far. This car holds the Bathurst production car lap record, has won Targa events outright and his Surface Transforms have no visible signs of wear either after 2 years of competitive running.
If you own and run them to the end of their life, it looks like they will be worth getting. If you are going to sell the car after a few years then it's probably not worth it purely financially. But one thing is for sure, anyone who specs PCCB's is a fool as long as these things are on the market.
My only question is when people are swapping out their rotors at 10 events, how compromised are the rotors actually at that point?
I know there are people on this forum that throw brake pads away way before they hit 50% and I literally knew a guy who would DE hoosier A6s and throw them out after each event (some of those events were evenings that he ran maybe 50km on them) so it's hard to gauge how used up something was when different people say they only got X events out of something. I do my own track maintenance so I'm ok pushing stuff to the edge to save parts costs as labour doesn't factor in (I'll take pads down to nothing for example as long as they still stop consistently and tires down to cords as long as they aren't heat cycled out).
I inspected my front rotors and after 4ish track days (It's more than that but I don't drive full events, I just instruct and go out on track when I feel like it. Car is at about 3500 km now, started pretty much only using it to go to and from the track after the 2000km break in): No signs of cracks. May be a slight lip formering on edge where the pad doesn't make contact and it usually has a ring of rust (I can catch my nail on it and it doesn't feel like it's just rust). Pads are maybe 70%. At this rate it is looking like I might have no issues swapping pads and keeping the OE rotors for round 2. If they end up cracking really badly before the 2nd set of pads get used up and that is why people are swapping them out at 10 events, I could easily see ST's in my future.
My only question is when people are swapping out their rotors at 10 events, how compromised are the rotors actually at that point?
I know there are people on this forum that throw brake pads away way before they hit 50% and I literally knew a guy who would DE hoosier A6s and throw them out after each event (some of those events were evenings that he ran maybe 50km on them) so it's hard to gauge how used up something was when different people say they only got X events out of something. I do my own track maintenance so I'm ok pushing stuff to the edge to save parts costs as labour doesn't factor in (I'll take pads down to nothing for example as long as they still stop consistently and tires down to cords as long as they aren't heat cycled out).
I inspected my front rotors and after 4ish track days (It's more than that but I don't drive full events, I just instruct and go out on track when I feel like it. Car is at about 3500 km now, started pretty much only using it to go to and from the track after the 2000km break in): No signs of cracks. May be a slight lip formering on edge where the pad doesn't make contact and it usually has a ring of rust (I can catch my nail on it and it doesn't feel like it's just rust). Pads are maybe 70%. At this rate it is looking like I might have no issues swapping pads and keeping the OE rotors for round 2. If they end up cracking really badly before the 2nd set of pads get used up and that is why people are swapping them out at 10 events, I could easily see ST's in my future.
Here are mine after 10 track days when I was cleaning out all the **** that builds up in the holes. I measure mine with a micrometer after each track day to keep track of thickness as part of my routine post track day inspections.
Based on the thickness wear rates I am seeing (2mm of wear allowed), they should last me about 20-30 track days. However the limiting factor is generally the heat checking and cracks that start to open up over time. At 10 track days I would say they have plenty left in them but coming from my previous car that would crack brand new rotors after a single track day we all know there is an element of luck involved there. I will let you know when I get there as that point will be where I decide whether or not I want to show off a new set of ST's.
As a point of interest (and relevant to the actual thread) my pads are due to wear out after about 12-15 track days, that's taking them down to about 3mm of material left. Note that the Pagid design drawings on the previous page quotes thicknesses that include the backplate, which is about 5mm thick. So the pads themselves actually have about 11-12mm of "meat" on them depending on the manufacturer.
07-03-2022, 02:59 PM
