HUH?

 

+1...Huh?

 

Have a look at some of the graphs which are avaialble for the differnt pads available. These show temperature against (what we will call retardive potential). Some pads need to vwearm up more before they achieve their maximum retardive potential, other pads are almost 'instant on'.

When you swapped cars, you also swapped pad material, or more accurately (as you could potentially have had the same pads) you changed to a different interaction between pad, pad deposit and disc.

The very first PCCBs available (almost certainly never reached the US, I think they were scheduled for replacement prior to the IAA 1999 when the product was launched) did have a marginal superiority to the very best iron rotors, but they were very noisy (think of taking a sander to the cut end of a steel cable), fragile and had an extremely short working life.

If you have pads with an 'instant on' characteristic, they will take a little adjusting to.

R+C

 

Seriously, you do have to make sure you are comparing like with like. If you want the 'instant on' effect, we can get that with iron rotors. Its just that PAG decided not to go down that path with their stock cars.

The PCCBs, which have not had as much spent on their integration testing as they should have had, have a digital tendency as implemented by PAG. In some respects it suits the PCCB branding/marketing effort.

R+C

 

I cant remember the exact details, and i dont have that book in front of me right now, but when you lift the throttle the car pre-loads the brakes, gets the pads right up against the rotors so it takes minimal effort to start stopping the car. I believe this is PCCB only, i will try and find my book to give the Porsche wording.

Mark

 

I don't think that's a PCCB feature. I think it's a feature of certain models, regardless of brake system...

 

ok I asked another tech, I had my systems crossed, i am still unsure if the GT3 had it, its a PSM 2.1 or PCM plus feature, mainly for 4wd cars. I need to find out if it crossed into the GT3... Gotta dig out that intro book...
Mark

 

PCCB's are only a "must have" if you must have them.

I didn't want them, & with over 13,000 miles now, I'd say that I really didn't need them. I'm still very happy with the steel brakes.

 

After a couple of 300km/hr to 100km/hr braking events on the German Autobahn I felt some remorse about not having ordered PCCBs. Should I have mortgaged my first born to pay for the PCCBs?

I just took the car to the track for the first time last Friday (a very technical one with lots of braking I might have to add) and the verdict is that the standard steel brakes felt as strong after 15 laps as after the first one - and that meant threshhold braking into virtually every corner. No remorse for having spent the money on Euro delivery instead.

 

leif997,

the sensation you described of the ceramics having:
1) very little pedal travel
2) very grabby
3) difficult to heal toe

All of these will go away once you have worn off a little bit of the outter layer of the ceramics. The way you described them above is exactly how I described them until I tracked them for the first time. In April at Limerock when it was cold and wet I had already put 2000miles on the car and it was my first day with the car. On the forth session after my confidence was good with the car I then decided to take it faster into bigben - a few things happened:
1) my foot went to the floor - I now know it to be green fade
2) the brake pedal engagement point forever moved about 1inch lower (this freaked me out and I brought it to the dealer and they didn't believe me)

So,

Here is what I think now.
When the pccbs first arrive they have a ruff surface that when it comes into contact with the pads causes a very abrupt and high engagement point.
Once enough heat / force is applied to the new rotors, this surface is sanded off and now the thermal properties of the pads and rotors will do what they ere designed to do.

And what happens is:
1) heal toe is now easy
2) the brakes are way easier to moderate

 

^ + 1

 

47,000 miles. 20+K on the track. rear rotors came with the car. Fronts are gen II with 10K track miles. Zero fade even with 60 minute sessions. They wear great but are fragile.

 

PCCBs have to be bedded in the same way iron rotor based systems need bedding in.

Proper transfer of material between pad and rotor remains important.

I have seen cars which have completed several thousand miles withoiut bedding in their PCCBs.

R+C

 

That is a feature of the C4, C4S, and turbo. It has nothing to do with PCCBs.

 

That's funny, I thought they were a must NOT have option. Silly me.