Ok, firstly, don't shit on Protex discs because Gordo cracked one. I've cracked every kind of disc, they all do it eventually.

Secondly, I doubt you had fade Dave, I didn't in exactly the same car and I reckon we were doing similar times. I suspect you had knock off. Anything 100mm hub with Brembos and decent tyres will get it. It's when the wheel bearing flexes enough that the huge rotor diameter pushes the pads back just enough that you get a long pedal. It'll pump up hard on the second pump, or give it a light pump with your left foot after a hard corner (like the chicane is a good example)

[QUOTE=dtrally;604959]Ok, firstly, don't shit on Protex discs because Gordo cracked one. I've cracked every kind of disc, they all do it eventually.

Secondly, I doubt you had fade Dave, I didn't in exactly the same car and I reckon we were doing similar times. I suspect you had knock off. Anything 100mm hub with Brembos and decent tyres will get it. It's when the wheel bearing flexes enough that the huge rotor diameter pushes the pads back just enough that you get a long pedal. It'll pump up hard on the second pump, or give it a light pump with your left foot after a hard corner (like the chicane is a good example)[/QUOTE]

Ah ok. It would explain it but is this just a nature of the beast or something that can be reticified?

If you were racing it you'd renew the wheel bearings every race, in the 12 hour endurance every pit stop.

You could update to the newer hubs that have a bigger bearing but I wouldn't bother, just learn to live with it and drive to minimise it.

Do this test. Drive up a wide quiet road or the freeway at night and swerve side to side several times without touching the brakes, get some cornering forces happening. Then see if you get the long pedal. If so, it's definately knock off.

Wasn't intentionally trying to shit on a brand. Apologies if it reads that way.

However, I think that given the age/condition and set of circumstances under which they discs cracked,
I would think twice now before purchasing the same product.

I would actually be really interested in seeing the material composition of the disc to try and determine why
they did crack. Unfortunately without know the temperatures they were at at the time it wouldn't really help
at this point.

Drilled rotors will always be more prone to cracking. Usually it's shock, temperature related. Getting really hot then suddenly cooled by water or wind etc. Both of which were in abundance that day.

[QUOTE=dtrally;604964]If you were racing it you'd renew the wheel bearings every race, in the 12 hour endurance every pit stop.

You could update to the newer hubs that have a bigger bearing but I wouldn't bother, just learn to live with it and drive to minimise it.

Do this test. Drive up a wide quiet road or the freeway at night and swerve side to side several times without touching the brakes, get some cornering forces happening. Then see if you get the long pedal. If so, it's definately knock off.[/QUOTE]

Ok ill give that a crack.

[QUOTE=Master D;604973]Ok ill give that a crack.[/QUOTE]

Haha, you said "crack"

[QUOTE=Saint_23;604966]Wasn't intentionally trying to shit on a brand. Apologies if it reads that way.

However, I think that given the age/condition and set of circumstances under which they discs cracked,
I would think twice now before purchasing the same product.

I would actually be really interested in seeing the material composition of the disc to try and determine why
they did crack. Unfortunately without know the temperatures they were at at the time it wouldn't really help
at this point.[/QUOTE]

It's all good Dave.

Speculatively speaking: My dumb logic is that the machining removes the chamfers around the cross drilling holes creating stress risers around the circumference of each hole.

All I can say about the material used is that it's hard compared to RDA slotteds I've used before.
I had EBC greens in with the Protex discs for the first 25,000km before the pads were down to 5mm & I fitted the QFM's. The wear on the rotor face was negligible at the pad change.

I had Ebc greens on RDA slotteds in my last WRX and the rotors wore at similar rate as the pads, once the pads were at 5mm the discs were throw away....But meh, RDA's are damn cheap! :)

There are not much interval for it to cool...
Both my front center caps went popped during my last collie and poor Adz have to run chasing the rolling center caps, all due to heat.

Went couple of circles in the open carpark to cool but obviously it wasn't cool enough.

I have found the best (Brembo) combo for Collie...and for that matter Barbs, RAC etc is DBA 5000 (never cracked one...rotor that is!), Pagid RS29 (19), Brembo fluid... do it once, do it right.
Best Subaru 4 pot is as above except Pagid RS4-2
Saving money on braking is a false economy...