Grant.revan

I have just been told by Subaru that I have heat damaged my front disks on my Legacy B4. They have suggested the use of Black Diamond drilled and grooved disks instead of the standard set. Has anyone any experience of these disks?

I need better cooling rather than better braking. Do i need drilled and grooved or just drilled. Am I going to warp these disks if they are less solid than the ones I am replacing.

Your input please. PS. The B4 is basically the 280BHP import version of the legacy with a twin turbo WRX engine. It goes quite fast hence the brake problem - fast stops from 140MPH seem to create a lot of heat.

Chris.Palmer

I'd recommend grooved but not cross-drilled (proned to cracking).

Here is a good thread that discusses the pros & cons of grooved, cross drilled & combi (grooved & cross drilled)

CharliePsycho

Have a look at this thread

Grant.revan

Now thats what I call a crack. Mine is just showing the little stress marks that you can see on either side of the huge crack in yours.

What did you replace the std disks with? Did they fix the problem.

All the info on disks seems to focus on brake performance not longevity. I don't want to keep forking out £250 every 20,000. Every 40,000 would be more like it.

It seems that X-drilling increases cooling but weakens the disk so they still crack - Sounds like a complete waste of time.

Grooves do not appear to weaken the disk but increase breaking power hence are more likely to get hot and overheat leading to cracking.

Can anyone recommend a set of disks that have performed for longer than their standard ones?

Help?