RS4 Brakes - Cauliflower pattern?

[Goodsteed]

Spotted a beautiful new RS4 in newcastle under lyme yesterday and noticed the they have a strange surface area pattern where the disk is s swept by the pads. Making the disk look cauliflower shaped on first glance...



Anyone know what causes this? Something to do with the size of the six pot caliper in relation to the disks?

[Kozy]

Just a pattern cut into the OD of the disc isn't it? After-market aesthetic modification I'd assume.

[jeremyc]

It's simply to reduce weight.

[Dave Hedgehog]

wave brakes

all new RS / R8 have them

[DaveCWK]

It's a 'style over function' thing. Cheap wavy edge brakes have been available on Ebay for a variety of cars for years, and also in applications where the spec of the brakes far exceeded the application e.g. mountain bikes/motorbikes. They are not in any way beneficial over traditional vented discs.

[Gusto]

I was of the impression it was to reduce un-sprung weight..... Can't believe it accounts for much though?

[Goodsteed]

Cheers, I guess I would reduce a Kg or so of unsprung weight given how bloody heavy disks are. Can't see why you wouldn't just manufacture a 340mm brake required rather than a wavy 360. Form over function I guess.

[ManOpener]

As others have said, I'd always though it was to achieve the best possible balance between weight and surface area.

[mackie1]

I've never seem them used in motorsport so I think it's only for looks/to stand out.

[larrylamb11]

Technically its designed to increase surface area with the objective of improving cooling

[98elise]

ManOpener said:

As others have said, I'd always though it was to achieve the best possible balance between weight and surface area.

Surely that would be a circle.

[Kozy]

larrylamb11 said:

Technically its designed to increase surface area with the objective of improving cooling

You're a salesman aren't you.

[kambites]

98elise said:

ManOpener said:

As others have said, I'd always though it was to achieve the best possible balance between weight and surface area.

Surely that would be a circle.

You'd think so.

[jeremyc]

kambites said:

98elise said:

ManOpener said:

As others have said, I'd always though it was to achieve the best possible balance between weight and surface area.

Surely that would be a circle.

You'd think so.

Not when the pads can't sweep the surface all the way to the outer edge, surely.

[Mr2Mike]

larrylamb11 said:

Technically its designed to increase surface area with the objective of improving cooling

So how does removing chunks of the outside of the swept area of the disc increase the total surface area?

The only area it increases is along the edges of the disc, which will not compensate for the amount lost on the sides.

[Dave Hedgehog]

Gusto said:

I was of the impression it was to reduce un-sprung weight..... Can't believe it accounts for much though?

9lbs on an RS4/RS5 apparently, I assume that's all 4 corners thou

http://www.popularmechanics.com/cars/news/auto-blo...

the only audi blurb i can find refers only to reducing weight

"They also feature revised friction rings which help to reduce weight by three kilograms, improving the balance of unsprung masses in the process. "





the RS4 mentions heat and weight

"The RS 4 Avant comes with a high-performance braking
system as standard. An 8-piston fixed calliper at the
front combines with 365mm Wave discs to harness the
formidable power of the car’s 4.2-litre V8 engine. This
innovative new Wave design has helped us save 3kg in
weight while improving performance through better
heat dissipation."

Edited by Dave Hedgehog on Tuesday 26th November 16:01

[RemyMartin]

Kawasaki have been using 'petal' discs on their zx-Xr range for a while.

[graeme4130]

According to the sales patter, it's to reduce weight and improve cooling
However, the brakes on my RS4 are like this and squeal like a pig

[Monkeylegend]

It also assists cadence braking without having to take your foot off the brakes.

[Dave Hedgehog]

graeme4130 said:

According to the sales patter, it's to reduce weight and improve cooling
However, the brakes on my RS4 are like this and squeal like a pig

that may just be the pad material thou, the TTRS and RS3 suffered from terrible brake squeal, the fix involved new calibers (with some form of weight balance on them) and a new pad compound that needs to be bedded in following a strict procedure, but it does cure them

i would contact Audi