Disc Heat Damage

[Daftlad]

TVR Sagaris, Mintex F4 pads. Discs are showing general and quite heavy surface cracks and cracks radiating from the drillings in the disc - fronts only. Noticed it during the week after a very good track day.

Is this aviodable or prevenatble by changing the disc from OEM??

[anonymous-user]

That's why a lot of people don't like drilled discs - the drilling creates stresses in the metal that can turn into cracks when heated. Some are available (i.e. Porsche) that have the holes cast in rather than drilled. All depends on what's available for the particular car.

[Sam_68]

^^^^ Like LexSport says.

Would strongly recommend that you replace the discs immediately. I've known cracked discs actually fracture & fragment at speed, which isn't fun.

[Daftlad]

Sam_68 said:

^^^^ Like LexSport says.

Would strongly recommend that you replace the discs immediately. I've known cracked discs actually fracture & fragment at speed, which isn't fun.

Thanks for the replies.
The car wont be used again until the discs are replaced.

I have the option to go with slotted discs rather than drilled so that would rid the concern over the cracking local to the drillings, but I also wondered about the general surface cracking away from the holes.

[leorest]

You are wise to not drive the car till the discs are replaced. I replaced pads on an X1/9 and noticed the disks were under minimum thickness but with no obvious signs of cracking. I ordered replacements and fitted them the following day. To my shock in this short time (with only one lazy commute to work) the old disks had developed radial cracks which had propagated from the circumference almost to the top hat. I recon I must of had one or two applications of the middle peddle before full catastrophic failure. This was with un-vented, non-drilled discs and a measly 1.5 litre torqueless motor. Grooved disks sound like the thing to go for. Check in the TVR forums to see if this is a common problem when tracking a Saggy on standard discs.