[SuzaFan]

Well,

I purchased a Performance Friction set for my MY09 GTR ca 5 months ago.
PF replacement slotted discs (OEM size) and PF 08 compound pads.
I made ca. 1000 km on these brakes (not driven during Winter at all)...
I bedded them in properly (as written in the manuals).
NO track days.
I do drive my car spirited though...
Now I see these cracks are starting to appear...
It is something I would not expect from the "racing" components...
Should I complain to the seller? (if the sellers sees this post here, I would appreciate his answer too)

 

[GTaaaaaarrrrrr!]

I assume you bought these new from a trader on here? Personally, I would expect many more miles than you've done. The photos don't show the cracks very well by the way. I'd be pursuing an FOC warranty replacement.

Edited to say I've viewed the brakes closer up and those cracks don't look good at all!

 

[SuzaFan]

I assume you bought these new from a trader on here? Personally, I would expect many more miles than you've done. The photos don't show the cracks very well by the way. I'd be pursuing an FOC warranty replacement.

Edited to say I've viewed the brakes closer up and those cracks don't look good at all!

Yes, you have to click on the thumbnail, then the cracks are clearly visible...
There are many of them on the disc... I just randomly took the picture of the disc...
And yes, I did buy those discs and pads from the trader here...
I don't want to say which one till I get some more thoughts...
I will send these pics to his email too...
Not a good advertisment for PF though...

 

[SuzaFan]

2 more pictures...
Looks even worse!

 

[Blade]

It looks like crazing and not cracks in those pics

 

[SuzaFan]

It looks like crazing and not cracks in those pics

That is why I am posting it here...
To hear the oppinions of the people who are more experienced...
Is this crazing normal?
Crazing is tiny cracking actually...
And it happened without the track day...
Are these discs up to GTRs performance and weight...?

 

[Blade]

If it is just surface crazing I would not worry. If the cracks ar more than that then be concerned

 

[The Brigand]

That is normal. Nothing to worry about.

It's heat crazing.

If the crack is deep all the way through the disc and extends all the way across the face then you need to change the discs.

Performance Friction are probably the best disc you will find and are used in professional motorsport the world over. They can develop a lot more crazing than what you currently have and still be up to the job required.

How are you finding the 08 pads?

 

[SuzaFan]

Hmm, now I feel a bit better...
I am sattisfied with the 08 pads, not too dusty and squeaky, but cold performance is noticably worse than OEM pads.
But the really DO bite when the brakes are at working temperature!

 

[grahamc]

In for the updates, because that looks rather bad to my UNTRAINED eye.... surely, those sorts of small cracks will eventually lead to larger cracks, especially if the brakes start to get pushed even more (like on a track).

 

[SuzaFan]

In for the updates, because that looks rather bad to my UNTRAINED eye.... surely, those sorts of small cracks will eventually lead to larger cracks, especially if the brakes start to get pushed even more (like on a track).

I was thinking the same...
This is why I need oppinions...
I would understand this after several track days, but without a track day...
I am not sattisfied with this level of PF discs performance
I am confused now, to be honest...

 

[Arcam]

2 more pictures...
Looks even worse!

You must have been giving them some hammer on the road then to get them like that seeing as you have not done any trackdays ... that looks like disks that have been used on trackdays to me.

 

[SuzaFan]

You must have been giving them some hammer on the road then to get them like that seeing as you have not done any trackdays ... that looks like disks that have been used on trackdays to me.

That is what worries me most!
How would those discs have looked if I went to track days?
And I made ca 1000-1500 km on them.
The only hammer I gave them was when bedding them in (2 times) and I made one more bedding in process for my rear PF pads (cause I purchased them later, the rear discs remained OEM).
And some spirited driving, on open roads, part of it is downhill...
Shouldn't "racing brakes" sustain that?

 

[The Brigand]

The cracks are on the surface of the disc. This surface will slowly wear down, making the disc thinner - once you reach the minimum disc thickness at which point the discs should be replaced. As it wears down some cracks will wear away and others will form. If all is well, they will look roughly how they look now until they reach minimum thickness.

Depending on the pad compound, the wear rate of the discs will differ. The 08 pads are an endurance race compound, disc wear rates will be a little lower than for example the 01 compound. However being a race pad they will quickly generate heat (the kinetic energy in the disc cannot be destroyed, only converted, in this case to heat and a little noise) - so you will get this type of heat crazing even if you don't go on the track.

If you want to get the best performance out of your pads and discs you need to monitor your brake surface temperatures and add or remove the amount of cooling to the system in order to stay in the correct heat range as recommended by the manufacturer. Too hot and you get various problems most resulting in vibration. Too cold and the pads do not work as they should and disc wear can be uneven or even substantially increased.

Whatever you do, you can forget about any warranty claim from the manufacturer as so far everything is as you would expect. Just keep an eye on the discs in case deeper, longer cracks develop. Generally all high performance car owners should inspect their brakes frequently anyway, as you would occasionally check your oil and other fluids.

 

[The Brigand]

This is an ALMS Corvette brake disc, you can just about see the crazing on the face of the disc:

 

[SuzaFan]

The cracks are on the surface of the disc. This surface will slowly wear down, making the disc thinner - once you reach the minimum disc thickness at which point the discs should be replaced. As it wears down some cracks will wear away and others will form. If all is well, they will look roughly how they look now until they reach minimum thickness.

Depending on the pad compound, the wear rate of the discs will differ. The 08 pads are an endurance race compound, disc wear rates will be a little lower than for example the 01 compound. However being a race pad they will quickly generate heat (the kinetic energy in the disc cannot be destroyed, only converted, in this case to heat and a little noise) - so you will get this type of heat crazing even if you don't go on the track.

If you want to get the best performance out of your pads and discs you need to monitor your brake surface temperatures and add or remove the amount of cooling to the system in order to stay in the correct heat range as recommended by the manufacturer. Too hot and you get various problems most resulting in vibration. Too cold and the pads do not work as they should and disc wear can be uneven or even substantially increased.

Whatever you do, you can forget about any warranty claim from the manufacturer as so far everything is as you would expect. Just keep an eye on the discs in case deeper, longer cracks develop. Generally all high performance car owners should inspect their brakes frequently anyway, as you would occasionally check your oil and other fluids.

Well, thanx for that detailed explanation how braking works... converting kinetic energy into heat... whoa, tell me more... :chairshot
The whole point is that people used to say that OEM brakes (Brembo) were low quality etc. and the same kind of cracks appeared ONLY around the drilled wholes and it happened after ca 12.000 km...
When the same cracks appear on the slotted PF disc, after ca 1.500 km, you are trying to convince me that it is normal and no problem...
You either work for PF or have some connection with selling the brakes here my friend...

 

[SuzaFan]

I sent the email regarding this issue to the company where I bought this...
No response...
Great customer service...
More and more I have a feeling that I was fooled around a bit with those brakes...

 

[grahamc]

I sent the email regarding this issue to the company where I bought this...
No response...
Great customer service...
More and more I have a feeling that I was fooled around a bit with those brakes...

Dont jump to that conclusion....

 

[SuzaFan]

Dont jump to that conclusion....

Believe me, I would really like to see that I am completely wrong...:banned:
Cause the brakes are not cheap and I really don't want to change the discs every 2000 kms...

 

[Wouter]

Hi SuzaFan,

I remember we spoke about the PFC discs when you were interested. I couldn't find if you ended up buying from us or someone else.

Anyway, I did check with PFC for an answer;

Hi Wouter,

These are normal heat crazing cracks and are nothing to worry about, ALL iron discs will develop these during their life as it is down to repeated heat cycles these only become an issue when they reach the ID or OD of the disc. Street use may cause these to develop more than race applications as in a race environment the discs warm up on the first lap and cool on the last. On street run at cold temps then see high temps during stops then cool again this is repeated over and over again!

Just remind the customer that there are no holes in the discs to crack from unlike the OE Brembo***8217;s that last no time.

Hope this helps.

Wouter