ldamelio

My first year of HPDE in a 2018 Cayman S, 6 track days so far and 22,500 total miles on car. Front pads have about 6.5 mm remaining after this amount of use (stock original pads and rotors). Recognizing that this isn't exact science, is 6.5 mm likely enough for an upcoming 3 day HPDE weekend? (Pocono double infield). TIA for thoughts.

987cs

I'd leave current ones on but bring an extra set. It's a good idea to always have spares anyway, especially so for a 3 day event. Not worth potentially losing track time. 6.5mm may or may not be okay, but remember you're likely going to be progressing rapidly at this point (using significantly more pad per session).

Not sure about the 718 but on my 987 it's extremely easy to change. Brilliantly engineered such that you don't have to remove the caliper. Someone will be able to help you if you ask nicely. I assume youll have an instructor too. Look up a video or how-to ahead of time. Jacking up the car is the hardest part. Borrow a jack and if you don't already have one bring a torque wrench to take the lug nuts off.

Alternatively if you don't want to potentially deal with swapping at the track, you could have the shop replace them and hang on to the used ones as backup.

zedcat

Presume you must pass a tech inspection? Check your tech form, sometimes minimum spec is given. Are the pads uniform thickness? Sometimes they will wear tapered, with the leading edge thinner. that may affect your decision. What was the original pad thickness? Commonly for oem pads the friction material is approx 10mm when new. If that's in the ballpark, simple math would suggest you should be ok. In the end, it's your call. Personally I hate working on the car in the paddock at a DE so if I have any doubt I change them.

edit- since thinner pads transfer more heat to the caliper and brake fluid, be sure your fluid is reasonably fresh and consider bleeding the calipers. if not already done consider a high temp fluid also.

Best of luck,

bswift

+1 for bringing spares. I ran brand new pads down to the backing plate in 8 Friday sessions on a heavy braking track. Fortunately I was able to have the dealer Parts department put a set aside for after hours pickup, otherwise I would have missed out on two of three event days.

Get an extra set of pads, caliper bolts and sensors if you're still using them. Personally I wired the sensor wires together so I don't have to deal with them anymore. Pad change on the 718 is definitely doable at the event but you will have to remove the front caliper so make sure you have something to support it.

Decent video for reference:

slilley

My opinion is to change them now. As @zedcat mentioned, with a thinner brake pad more brake components are going to be closer to a red-hot rotor. Things like the rubber seals on the caliper pistons are that much closer to the rotors. And those are a PITA to R&R - BTDT.

Change your pads now, and throw those used pads back in the box and put them in your "spares" collection that you take with you to the track. That way, you've always got a set of spare pads that will last a day or two.

Most likely 6mm is enough to easily complete 3 days at Pocono with a mm or two remaining, but as someone who's unexpectedly taken a set of front pads down to the backing plates at Watkins Glen, I know that it's no fun scrambling track-side to swap in replacements. Much like a tank of gas, it also seems like the last half of the pads goes away much faster than the first half!

OP, I'm only about an hour from Pocono, so if you happen to live near Berks County (19610), PM me and we can meet up sometime!

Zhao

People often say that on here.... it's one of those things that sounds good and you can even back it up with logic, but when it comes down to it, it doesn't make one bit of difference.

If you knew how brake calipers worked you'd know the seals are no closer to the rotor no matter what thickness the brake pads are and those rubber seals can take a lot more heat than what 99% of people on here can generate. Even running just backing plates without any pads, which generate an extreme amount of heat, will likely not do anything to those seals, because I have seen exactly that done and OE rubber seals didn't blister, crack, or disintegrate. I have only ever seen cheap chinese replacement seals do that.

Jet Jockey

Sorry, but are you talking about the piston dust shields/boots?

If you track your car extensively, you will destroy those dust shields/boots, I know because mine need to be replaced. There are better ones than the OEM ones too made of silicone that resist to the very high heat produced when tracking.

Zhao

Ya, the dust seal (can't imagine anyone would be talking about anything else either). I do track my cars extensively. Enough I have more laps than anyone else at one track. My race car has over 10000km almost all of which are at other tracks (and 35 year old calipers on it). I have owned and tracked a lot of different cars too. Never seen an problem with a OE caliper seal on any of my cars.

I would say if the OE caliper dust seal disintegrated either porsche (or whatever car it was on) uses a very poor material, they had a bad run, or the track they drive is unique to putting a lot more heat into calipers than other tracks. Pad thickness is not going to be responsible for that, and should not be factored in at all. If someone is running OE pads and they aren't glazing, they aren't generating much heat either.

Jet Jockey

Well I can tell you it seems to be totally normal on some Porsche cars... My friend put 15,000 kilometers of track in 3 years on his Cayman GTS and the rubber dust shields were destroyed several times, basically had to change them every year.

Last year I had to change some of them and last week when I did a pad change on the front calipers all 8 pistons were destroyed and will need replacement (see pictures).

Doing a quick research on Rennlist, I found out this was not so uncommon with many people having the same issue, in fact it happens a lot.

I was told of a company that makes silicone based dust shield that they guaranty will never melt of disintegrate like the OE made ones or else they replace them at no cost... Looking into getting a complete set for the two front calipers.

This is after a year being on the car with some heavy track use... Keep in mind the car is stored for at least 5 months during the winter.





Here's a Porsche PCCB 6 pot caliper with destroyed OE dust shields.



Here's the caliper after the rebuilt with those "blue/silicone" high temperature dust shields.

slilley

I've got over 55 track days under my belt, but all of it has been in BMWs and Miatas that use a different (cheaper?) sliding caliper design than what Porsche uses. And I've rebuilt the brakes after the dust seals were toast in those cars...it's a fiddly job that I don't enjoy because you never want to introduce air into the braking systems. In those "lesser" cars, the dust seals do get closer to the rotors as the pads wear. But I can see what @Zhao is saying about the Porsche seals not getting any closer, since it's (apparently) the caliper pistons that extend as the pads wear down.

In either case, I still stand behind my recommendation to the OP to change the pads now. When in doubt, change them out! It's cheap insurance to replace them now, and you won't have to worry about pad wear again for another 3-4+ events. (Although ALWAYS check your pads before every track event - just because you can't be too safe when it comes to brakes.)

nineball

our de events require 50% pad at a minimum, and while 65% is more it's not by much. i vote new pads and a fluid change. personally i use this:

https://www.motul.com/ca/en-US/produ...0-factory-line