Cracked B7RS4 disks (on RS6 calipers)

[MarkB]

Really? I did not know about this??!! (I can feel a massive price tag here!!! )

Can I use those disks the RS6 Calipers??

Nope, you'll need new calipers. I'll think you'll be the first with them fitted. I can't see why they wouldn't fit though

[fade2grey]

they look like they've been drilled rather than cast with holes in - which reading the above would be right. AFAIK cross drilled disks are actually cast with the holes in them. The cracks are from stress risers caused by the drilling & the fact the metal doesn't flow around them.

Personally, I wouldn't use disks which have been drilled, to be honest I've never seen any improvement over grooved - which although will degrade your pads just as much help in all sorts of ways, de-glazing, moving water etc.

Just my 2p happy to be proven wrong if anyone else experiences differ..

[viperbl]

Personally, I wouldn't use disks which have been drilled, to be honest I've never seen any improvement over grooved - which although will degrade your pads just as much help in all sorts of ways, de-glazing, moving water etc.

Cheers for that ...

but then, I can get B7 drillied floating disks, or grooved RS6 solid disks??

All trade off's I guess ...

[viperbl]

Just found this

Great FAQ from Brembo ...

So, floating really does work, since my disks are not warped, and this is one pet hate of mine, I get like that massive rage of anger when my disks get warped and start vibrating under braking ... so guess I am gonna stick with B7 RS4 disks ...

[Nige_RS4]

Rich, do you have the Phaeton ducts fitted? They may not solve the problem you have, but every little helps?

[viperbl]

Yea Nige, got them of MRC as well and had them fitted ...

I am just hoping that it was my ignorance with the dust in the holes that has caused the cracking and not the high temps ... but, since the floating thing goes a long way to stop warping, I think I must try these disks again...

[derdle]

Jes*s...I thought only Movits went that way so quickly! Some MoT stations will fail the disks because of those cracks. Wonder whether you need to consider different pads (next time around) or changing the pads before they become too worn. The more worn the pads, the more heat generated and not dispersed (less pad material to soak up the heat).

Just my 2p...but you are probably looking for more than 2p. Is this a symptom of unrestricted roads and those video clips you post?
Paul

[DavidT]

Like I said before, you've done pretty well out of them Rich. How much extreme use did you put them to ? 3 sets of pads suggest the answer is 'a lot'

If you want them to last longer, you have plenty of options: drive slower, brake less, lighten the car etc. etc.

Seriously, be happy that they work well and just accept what they cost. You will not see a brake setup like this in use on a racing car, but thats mostly what you use it for on your road car.

[ash318]

i too have a set of discs that are cracked like yours,although i have the rs6+ discs,im on my second set of standard pads and have done a couple of track days and three trips to the ring.Overall i am very happy with the way they work but i was looking at getting the rs4 b7 discs because they are fully floating however after drooling over an r8 in my local showroom i was pleased to see rs6+ discs on that so they must be good,also gallardos use the same discs as well.Just thought it might help you decide.

[viperbl]

Thanks, I actaully ordered another set of the B7 disks today! I decided that even although they cracked, I have been happy with the performance, AND they did not warp ..., so, all in all, I am gonna go with them again!

I also had to get two new rear RS4 disks, I feel light headed with the amount of cash I have parted with today!!! but, lets face it, it is an important part of the car!!