Have my front disc had it (pictures inside)

[Gibbo205]

Hi there

I know drilled disc always tend to crack around the holes, but after 4 track days mine are showing quite a few cracks now on the front, rears are fine. Pictures:-




They are 997 Turbo disc.
The cracks seem to be on the surface only, if you look at the drilled holes you can see the cracks are surface only, hence is it just cosmetic?

Are these OK or are they in urgent need of replacing, really seeking advice from others who drive hard or track their cars.

[bobsan]

Could go bit more, especially on road, its when they reach edge of disc you need to change.

[BertBert]

I certainly would be changing them for track use at this stage. A surface crack is only a surface crack till it goes all the way through! They look quite well developed to me.
Bert

[agtlaw]

Look fine to me. Can't even see any channels / grooves. Try harder.

Measure the thickness of the discs?

[Gibbo205]

agtlaw said:

Look fine to me. Can't even see any channels / grooves. Try harder.

Measure the thickness of the discs?

No lip at present, assume if thickness is reduced they will develop a lip like normal steel disc do?

[shoestring7]

I thought the holes in Porsche discs were cast, not drilled, for this very reason?

SS7

[[AJ]]

Take the opportunity to get some Alcon discs and pads on there if you don't need OPC warranty.

[Trev450]

I had a lot of problems with drilled discs cracking on my track Evo. I tried varied different makes, AP, PF, etc but they all went the same way. I now use AP grooved discs and they are not showing any signs of cracking yet and have done about 9 events so far.

[STiG911]

I would say there's life in them thar discs yet, particularly as there's no lip.
Also, assuming that this is on your to-do list, make sure you get a drill bit to fit and clean out all the holes, as this will compound the issue...

[Gibbo205]

STiG911 said:

I would say there's life in them thar discs yet, particularly as there's no lip.
Also, assuming that this is on your to-do list, make sure you get a drill bit to fit and clean out all the holes, as this will compound the issue...

Yeah shall do.

On another note the PF08 pads are amazing, zero fade and so far they seem to be showing zero wear, very impressive pad.

[keep it lit]

[AJ] said:

Take the opportunity to get some Alcon discs and pads on there if you don't need OPC warranty.

mine are over two years old, 25 trackdays inc double headers at Spa & Ring and a large euro tour...



lip proud

[Trev450]

Gibbo205 said:

On another note the PF08 pads are amazing, zero fade and so far they seem to be showing zero wear, very impressive pad.

PF pads are excellent. I use the 01's in my track Evo and they're on their third season now and less than half worn.

[thegoose]

Hmm, I was driving a Honda S2000 recently with discs that were cracked but looked better than that (not sure what type - non-standard and with EBC redstuff pads). I drove it, err, "spiritedly" to drop it off (as fast as it would go down the Tatton Mile for those that know it) for valeting, arriving there without them having cooled a lot admittedly, and when I collected it there was a bad vibration through the pedal - turned out one of the discs had developed a radial crack right across (imagine a minute hand of a clock).

Needless to say I nursed it to a garage and had new discs & pads fitted. God know what would have happened if it'd failed on track

[Gibbo205]

Do girodisc offer anything that will fit 997.1 turbo in the front? Alcon are a bit rich for me.

[keep it lit]

Gibbo205 said:

Alcon are a bit rich for me.

you get what you pay for...

how much did those 997 discs cost & how long have they been on your car?

[Gibbo205]

keep it lit said:

you get what you pay for...

how much did those 997 discs cost & how long have they been on your car?

£400 for front pair m8, 4 track days on them so far and maybe 5000 road miles....

[Trev450]

Gibbo, give these people a call. They have an excellent reputation on a number of forums - nothing to do with me personally though.

http://www.godspeedbrakes.co.uk/

[MadMark981]

Gibbo205 said:

Hi there

I know drilled disc always tend to crack around the holes, but after 4 track days mine are showing quite a few cracks now on the front, rears are fine. Pictures:-




They are 997 Turbo disc.
The cracks seem to be on the surface only, if you look at the drilled holes you can see the cracks are surface only, hence is it just cosmetic?

Are these OK or are they in urgent need of replacing, really seeking advice from others who drive hard or track their cars.

Holy sheet Gibbo! IMHO - they need binning! You would only have to be doing a "spirited" drive on the road and suddenly cool them by going through a puddle for those cracks to become fissures and then onto disc failure. I've always worked on the principle that anything longer than a 5mm crack extending from a drilled hole = bin!

Perhaps it's time to start thinking about some grooved Girodisc / AP / Carbon Metallic / Willwood?

[Gibbo205]

MadMark981 said:

Holy sheet Gibbo! IMHO - they need binning! You would only have to be doing a "spirited" drive on the road and suddenly cool them by going through a puddle for those cracks to become fissures and then onto disc failure. I've always worked on the principle that anything longer than a 5mm crack extending from a drilled hole = bin!

Perhaps it's time to start thinking about some grooved Girodisc / AP / Carbon Metallic / Willwood?

Girodisc don't seem to do front disc in 997.1 turbo size according to their website.

[kingstondc5]

Giro disc are also more expensive than Alcon/PF at this moment in time due to exchange rates