RS6 Calipers -> RS6 or B7 RS4 Disks/Pads?

[viperbl]

Think I am going to go for this RS6 setup but can't decide wither to go for the RS6 or RS4 disks ... I am thinking RS6 disks, I assume they will be 'stronger' ? and since they are going to be used heavily I am thinking this is the better option?

Also, what pads is anyone else running on these?

[saf]

What i know about the RS4 B7 discs are that they will fit straight on as long as your wheels accomodate it.

I think if youre running 19's youre pretty safe.

Also RS4 B7 discs are said to have true floating heads.

Not sure about the RS6 ones being stronger though.

everyone ive asked are using the standard RS6 pads for the brake set as far as i know. They about £170 a set of front pads.

Usually the RS4 B7 are more expensive discs but they dont require a bracket to fit the wheels.

[MarkB]

RS6 disc's are better because they are handed, but do require a bracket for the caliper... Both are floating I beleave.

[saf]

I was told that the RS4 B7 have a true floating head, whilst the RS6 ones are described as floating, but are kind of semi floating.

Im not sure which is better. But I know the RS6 Discs are not ventilated but the RS6 plus ones are.

What do you mean by the RS6 ones are handed?

Thanks

[MCB]

What do you mean by the RS6 ones are handed?

Discs have directional vanes

[saf]

And what is the advantage of directional veins?

Are those the RS6 or the RS6 plus ones?

[philipwalker]

And what is the advantage of directional veins?

Are those the RS6 or the RS6 plus ones?

Cooling

[viperbl]

And what is the advantage of directional veins?

Are those the RS6 or the RS6 plus ones?

Cooling

So, now I am thinking for hard use (because of better cooling) the RS6 ones would be better???

I can't seem to find what this true floating thing is all about? Can anyone direct me to a past post or explain?? thanks!

[MCB]

Better cooling and I think they both have them

[MCB]

A bit slow there!

[MCB]

Check out http://www.apracing.com/roadcar/brakekit/brakediscs.htm and various links on the site

[MarkB]

I can't remember what the disc's look like on the RS6 but they may be floating much like the B5 RS4 on pins.

[SteveH]

The RS6 discs and calipers are manufactured by Brembo, and the RS6 pads are manufactured by Pagid. Both RS6 and RS6 Plus discs are ventillated (longitdinal vent as such), but the "plus" discs are also cross drilled for improved cooling and to allow the gasses created when the pad comes into contact with the disc.

RS6 & RS6 Plus discs are semi floating, the bell of the disc that is mounted on the hub is a seperate casting to the rim of the disc that comes into contact with the pads. A true floating disc has a mechanical/slotted connection to the bell, whereas the RS6 disc is connected via rather more rigidly mounted studs, hence being called semi-floating as its a bit of a hybrid. I believe that this "floating" seperation increases durability of the disc, allowing the disc to expand and contract with the heating and cooling under use e.g. reduced risk of warping.

The better the cooling, the more durable the components in question; I learnt this weekend that the inside face of a disc and the inside pads wear faster as the outside face naturally gets better cooling through the wheels. So you need to be careful when simply looking through your alloys visually inspecting your discs, as all may look good on the outside, but the inside face could be worn to bits!

This website is superb for brake info: http://www.stoptech.com/tech_info/tech_ ... pers.shtml

In fact, from stoptech:

Disc : The rotating portion of a disc brake system. Mechanically attached to the axle, and therefore rotating with the wheel and tire the disc provides the moving friction surface of the system while the pads provide the stationary friction surfaces. Except for racing, discs are normally manufactured from one of several grades of cast iron. Some European front drive passenger cars, where the rear brakes do very little work, are using aluminum metal matrix rear discs to save weight. Most professional racing cars use carbon/carbon discs.

1. One-piece disc : A disc cast in one piece with its hat or bell. This is the inexpensive way to manufacture a disc and is perfectly adequate for normal use. There are some tricks to the design to reduce distortion.

2. Floating disc : The norm in racing, the floating or two-piece disc consists of a friction disc mechanically attached to the hat either through dogs or through drive pins. Properly designed this system allows the disc to dilate (grow radially) without distortion and to float axially, greatly reducing drag.

3. Solid disc : A disc cast as a solid piece suitable for light cars not subjected to extreme braking.

4. Ventilated disc : A disc cast with internal cooling passages. The norm in racing, high performance and heavy vehicles.

Drilled or cross-drilled rotors : Discs that have been drilled through with a non-intersecting pattern of radial holes. The objects are to provide a number of paths to get rid of the boundary layer of out gassed volatiles and incandescent particles of friction material and to increase "bite" through the provision of many leading edges. The advent of carbon metallic friction materials with their increased temperatures and thermal shock characteristics ended the day of the drilled disc in professional racing. They are still seen (mainly as cosmetic items) on motorbikes and some road going sports cars. Typically in original equipment road car applications these holes are cast then finished machined to provide the best possible conditions by which to resist cracking in use. But they will crack eventually under the circumstances described in another section (see Cracking). Properly designed, drilled discs tend to operate cooler than non-drilled ventilated discs of the same design due the higher flow rates through the vents from the supplemental inlets and increased surface area in the hole. That's right, inlets. The flow is into the hole and out through the vent to the OD of the disc. If discs are to be drilled, the external edges of the holes must be chamfered (or, better yet, radiused) and should also be peened

[MarkB]

Worth doing to help against Steve's point above about inner side wearing more is to fit Phaeton ducts. They will give more cooling to the inner side. Do a search...

[philipwalker]

The two-piece disc allows for a lighter material to used in the centre part, the bell. Giving less un-sprung weight.