How many pistons..

[McBurn4ever]

Anyone who knows how many pistons the S4b6 original calipers has?


:s4addict:

[RS4Ever]

im not so sure, and i havew a feeling i might be wrong.. but doesnt each cylinder have 1 piston? totalling 8 pistons?

[sturs6]

Originally posted by RS4Ever
im not so sure, and i havew a feeling i might be wrong.. but doesnt each cylinder have 1 piston? totalling 8 pistons?

He is talking about the brakes I believe and not the engine.

[Klint]

A Pure guess, but I recon it would have 4 pistons up front.

[McBurn4ever]

That's right! I don't mean the engine.....but the brakes..

Here's a pic of some Brembo calipers:
http://www.brembo.com/NR/rdonlyres/B06AFA0B-82F0-4569-BDFD-EEDBCFC03E3E/0/hpf_l_009.jpg


No one who knows??

:s4addict:

[Erik]

I tried to find out but didn't find anything.

If you're looking to upgrade, just don't count the calipers.
Check things like pad area, piston size etc. as well.

I was very happy with my front Movit kit, really changed the car and the feeling in the brakes.

[Audihead]

Front Brakes : 4 piston calipers 345mmX30mm rotors
Rear Brakes : 1 piston calipers 302mmX22mm rotors
Called and asked the service tech at local dealer.

:mech:

:s4addict: -Bimmerhead

[McBurn4ever]

Originally posted by Bimmerhead
Front Brakes : 4 piston calipers 345mmX30mm rotors
Rear Brakes : 1 piston calipers 302mmX22mm rotors
Called and asked the service tech at local dealer.

:mech:

:s4addict: -Bimmerhead

Thanks!!
I guess I could have done that also...just didn't think of it.. :harass: :rolleyes:

Right now I don't have any plans on upgrading..especially since I've just had my front discs and pads replaced on warranty..
But I have to admit that the thought has crossed my mind..maybe some RS6-lunatic who just changed his brakes to 8-piston Brembo would like to sell his "old" RS6-brakes.. :hihi:

[Erik]

Originally posted by McBurn4ever
maybe some RS6-lunatic who just changed his brakes to 8-piston Brembo would like to sell his "old" RS6-brakes.. :hihi:

You can buy ours after we finished Highway Challenge. :burnout: :rotflmao:

[Audihead]

What's the Highway Challenge? Is it a sanctioned event by a club or racing series? Sounds interesting.

:s4addict: -Bimmerhead

[Erik]

Originally posted by Bimmerhead
What's the Highway Challenge? Is it a sanctioned event by a club or racing series? Sounds interesting.


Please wait for more information :)

BTW: You have a pm in another matter.

[RS4Ever]

thanks for clearing that up... learning new things everyday.

you guys know a lot of info... a question about brakes.. when they say vented disc brakes in a certain cars specifications.. how come some actually look vented (with the holes in the drum) and some are a flat surface but are still called vented?
such as both the RS6 and the S4 are said to have vented disc brakes but the RS6 has holes in the drum and the S4 is a flat surface drum.

thanks.

[Nordschleife]

Originally posted by RS4Ever
a question about brakes..

when they say vented disc brakes in a certain cars specifications..

how come some actually look vented (with the holes in the drum) and some are a flat surface but are still called vented?

such as both the RS6 and the S4 are said to have vented disc brakes but the RS6 has holes in the drum and the S4 is a flat surface drum.

thanks.

I'll try to explain

There are two priincipal components in a disk brake ssystem

- the rotor (what you call drum) also called a disk
- the calliper

the rotor goes round as its attached to the same axle stub as the wheel

the calliper stays in place and clamps each side of the rotor when you apply the brakes

when you apply the brakes, you lose speed and your forward motion gets turns into heat

most of the heat ends up in the rotors

because the rotors are usually made of iron, they are very good at absorbing heat, but they have their limits

to help get rid of the heat, brake system designers have improved the ventilation of the brakes in general and disks in particular.

ventilated disks have channels through the centre of them - the air is supposed to flow from the centre to the outside, propelled by centrifugal force. The air exits through the holes you see on the outside rim of the rotor.

rotors may also be slotted or cross drilled (pierced). There are several reasons for this -

in the past brake pads were made of material which emitted gas under use, this gas caused a layer to build up between pad and rotor. The holes in the flat surface of the rotor allow the gas to escape - modern brake pads do not 'gas'

in the wet, rain can build on the flat surface of the rotor, this has to be removed before brakes can be fully applied, holes in the rotor allow the water to be removed more quickly

there is a debate as to the benefits of slotted versus cross drilled brakes. It is felt that slotted rotors do not crack as easily as cross drilled rotors. Cracked rotors cause vibrations and accelerate pad wear. In order to reduce the tendency to crack, high quality rotors may not be cross-drilled, but rather have the 'piercing' cast in to them at time of manufacture. These are called pierced rotors, frequently seen on Porsches. piercing does not remove the tendency to crack, it only ameliorates it. Whilst slotted rotors do not crack as easily as pierced or cross-drilled rotors, it is commonly felt that they accelerate pad wear.

there are three important dimensional elements when considering rotors

outside diameter
thickness
inside diameter

the more material there is in the rotor, the more heat it can absorb

However, the heavier the rotor, the harder the car will be to turn in and the more work the suspension will have to do - remember, the rotors are unsprung mass, which car designers generally try to minimise to improve handling, noise and comfort.

I hope this explains the basics for you, there is a great deal more

R+C

[sturs6]

What happens then when the rotor gets filled with brake dust. Is there a way to clean it out without harming the rotor? This seems like a good reason to have slotted rotors instead of cross drilled...

-Stuart

[Nordschleife]

If the holes in the rotor do get filled with brake pad dust, clean them out with a pipe cleaner (joke), or a power drill - very quick and easy.

R+C

[sturs6]

Originally posted by Nordschleife
If the holes in the rotor do get filled with brake pad dust, clean them out with a pipe cleaner (joke), or a power drill - very quick and easy.

R+C
Is the power drill a joke also and does it make that big of a difference in normal street driving.

[Nordschleife]

there is no joke about the power drill. The car won't mind if you ask it open wide beforehand!

Use an old smaller diameter bit, you aren't drilling out the rotor, just removing the accumated pad material.

Whether it makes a difference in ordinary driving is most dependent upon the pad material, some are dustier than others.

Its not a factor for race rotors, they are a disposable after each race.

R+C

[sturs6]

Great thanks...:thumb:

[RS4Ever]

wow
thanks a lot.
great explaination.

[7:53 RS6]

Originally posted by McBurn4ever
Thanks!!
I guess I could have done that also...just didn't think of it.. :harass: :rolleyes:

Right now I don't have any plans on upgrading..especially since I've just had my front discs and pads replaced on warranty..
But I have to admit that the thought has crossed my mind..maybe some RS6-lunatic who just changed his brakes to 8-piston Brembo would like to sell his "old" RS6-brakes.. :hihi:

You could by my cross driled front rotors, they are now 365mmx32 mm newly machined insted of new365mmx 34mm.

[7:53 RS6]

By the way RS6 stock brakes are brembo 8 pistons caliper, sorry but i cant sell them.

[Nordschleife]

Originally posted by 8:29 RS6
You could by my cross driled front rotors, they are now 365mmx32 mm newly machined insted of new365mmx 34mm.

I know you are new to this, but

Does it not occur to you that heating your rotors to such a temperature that they glow red, causes them to be tempered, they have undergone permanent change, they are not worth anything, their ability to heat up and cool down is permanently impared. I dare say the machine shop cursed you as they wore out tools on the rotors.

When Audi demonstrate the RS6 they expect to change rotors on a daily basis.

It would be dangerous to use these rotors, selling them is a bad idea.

R+C

[7:53 RS6]

Originally posted by Nordschleife
If the holes in the rotor do get filled with brake pad dust, clean them out with a pipe cleaner (joke), or a power drill - very quick and easy.

R+C
Sure you can powerdrill of the dust in the holes, but its not that quick. The reason is that the disc is not cross drilled from one side to another. (The holes one the outer disc side is not in line whit the holes on the iner disc side). Its quick to drill of the outer side. But if you want to drill the in side(recomended while doing outer side) you have to take away the metal plate(dont know name in english)inside the rotor, or take the rotor of.

[7:53 RS6]

Originally posted by Nordschleife
I know you are new to this, but

Does it not occur to you that heating your rotors to such a temperature that they glow red, causes them to be tempered, they have undergone permanent change, they are not worth anything, their ability to heat up and cool down is permanently impared. I dare say the machine shop cursed you as they wore out tools on the rotors.

When Audi demonstrate the RS6 they expect to change rotors on a daily basis.

It would be dangerous to use these rotors, selling them is a bad idea.

R+C
There is no problem use this rotor if you know about it!
Well im not new to this.
Done this many times and becuse i relly use my cars, rotor and tiers and pads are like toiletpaper for me. You use it up.
To not ruin my self i fore exampel macine rotors and then use it some more.
Its no problem to run macined disc if you know about it.
And check the pads from time to time to prewent pistons to go over its one axel..that could be a problem but not on my discs relly, its not under 32mm.
Its not recomended to use RS6 disc that is under minimum alloens 32mm, its printed on the rotor if you dident se that!

At the time when you could get aspets material i also made my one pads and as you now that material could take heat, cant get it now days. You had the stock pad and cut out the samme size of the material then put it to the steel frame (thing holding the pads) drove this many years on a Alpina on track, the same alpina i wraped many rotors and macined them and used them many more laps and then throw them. The above whriting of you show that thing like this is not something you know about. But many things you know.

PS:In you above rotor lesson you forgot to mention that driled rotors dont wrap as easy as non driled DS

Of course Audi change discs if they dident and somting did hapen to a klient driving......well its logic!

[7:53 RS6]

Nordo.

Its also logic that Audi and BMW on their courses nowdays whit ESP on the market are phusing for peopel to driving with ESP. And most clerly are not alowing peopels to drive whit it of.

They would lose to many cars and maybee peopel if alowed without ESP.
BMW fharertraining at The ring did lose some becuse of this tried.

PS:The ESP tecknik today is not so god that a god driver can go as fast whit esp that he can go whit out, especally on rear driven cars. in the future for sure but not now. DS

[Nordschleife]

Originally posted by 8:29 RS6
There is no problem use this rotor if you know about it!
Well im not new to this.
Done this many times and becuse i relly use my cars, rotor and tiers and pads are like toiletpaper for me. You use it up.


you said it, not me!




At the time when you could get aspets material i also made my one pads and as you now that material could take heat, cant get it now days. You had the stock pad and cut out the samme size of the material then put it to the steel frame (thing holding the pads) drove this many years on a Alpina on track, the same alpina i wraped many rotors and macined them and used them many more laps and then throw them. The above whriting of you show that thing like this is not something you know about. But many things you know.


so all Ferodo, Pagid, Hawk, EBS, Performance Friction etc., need is some asbestos......



PS:In you above rotor lesson you forgot to mention that driled rotors dont wrap as easy as non driled DS


rotors do not warp - what happens is that material is transferred from the pads to the rotor.



Of course Audi change discs if they dident and somting did hapen to a klient driving......well its logic!

Yet again, you misunderstood my point - Audi throws the old rotors away because the are useless, they have been 'blued', they have been heat cycled, they are worthless.

R+C

[Nordschleife]

Originally posted by 8:29 RS6
Nordo.

Its also logic that Audi and BMW on their courses nowdays whit ESP on the market are phusing for peopel to driving with ESP. And most clerly are not alowing peopels to drive whit it of.

They would lose to many cars and maybee peopel if alowed without ESP.
BMW fharertraining at The ring did lose some becuse of this tried.

PS:The ESP tecknik today is not so god that a god driver can go as fast whit esp that he can go whit out, especally on rear driven cars. in the future for sure but not now. DS

Well, you are a bit behind the times with your information. Take the Ferrari Enzo, only Michael Schumacher and Andrea Bertolini are faster with the ESP turned off, even other Ferrari drivers are faster with the ESP in race mode.

If you learned to drive properly with ESP on, you would be faster than you presently are with ESP off. Once you had perfected the ESP on technique, you could then return to driving with the ESP off and would not only be faster still but much smoother than your present technique.

R+C

[7:53 RS6]

Originally posted by Nordschleife
Well, you are a bit behind the times with your information. Take the Ferrari Enzo, only Michael Schumacher and Andrea Bertolini are faster with the ESP turned off, even other Ferrari drivers are faster with the ESP in race mode.

If you learned to drive properly with ESP on, you would be faster than you presently are with ESP off. Once you had perfected the ESP on technique, you could then return to driving with the ESP off and would not only be faster still but much smoother than your present technique.
R+C

Behind? thats exatly what i said, the god driver drives faster with esp of. Btw i did not have the Enzo in mind but nontheless with its supirior tecknologi its still faster with esp of. Think of how much faster schumi is in a RS6 with esp off vs on.

Sorry but before you show me under 8:29 and for exampel sliding tow bends in a row in Hatzenbach with no esp. I cant relly take you to seriosly when you are handing out drivinglessons all time. If you think about it you will understand.

[7:53 RS6]

Originally posted by Nordschleife
you said it, not me!



so all Ferodo, Pagid, Hawk, EBS, Performance Friction etc., need is some asbestos......



rotors do not warp - what happens is that material is transferred from the pads to the rotor.



Yet again, you misunderstood my point - Audi throws the old rotors away because the are useless, they have been 'blued', they have been heat cycled, they are worthless.

R+C
1. you bet!

2.You missed my point, doing these asbets brakes did make my money to last longer as whit the rotors.
Compered to bying new alpina pads doing my own in the race shop was close to nothing if compered the price. And they could take seriusly more heat and lasted much longer than stock pads .

3. Well if a rotor is worn down and taking to much it can whrap(slagit sig in swedish). Try to explain, it feels like relly big vibrations in the stering when braking, espesally when the disc is cold.
If pusing it a bit when cold the disc will get heat agian and it will fell better but not all god. When leavin track to pit and disc get cold again its the same big vibrations. This disc is wraped, and can easely be macined to a low cost to work a litel bit longer then thrown away.
Non driled disc are easy to macine you can take both sides at once. Drilled are more tuff and nead other macine. If I was going crusin whit my cars and wouldent being needed to change things often i would maybee not macine my rotors to make them last that bit longer. If i had a ton of money i wouldent doit even if i used things up.

4. Useles for AUDI but not for me. Had many fun laps whit macined rotors. Seing what you wrote im sure you never macined one rotor.

[7:53 RS6]

Originally posted by 8:29 RS6
Sure you can powerdrill of the dust in the holes, but its not that quick. The reason is that the disc is not cross drilled from one side to another. (The holes one the outer disc side is not in line whit the holes on the iner disc side). Its quick to drill of the outer side. But if you want to drill the in side(recomended while doing outer side) you have to take away the metal plate(dont know name in english)inside the rotor, or take the rotor of.



Well Mr know it all, where is the coment on this?
My guess is that you thougt the hols was drilled straight thru the complete disc. If they where it would be quick and easy, but they are not!
Are you:blush:

[Audihead]

Originally posted by 8:29 RS6
Well Mr know it all, where is the coment on this?
My guess is that you thougt the hols was drilled straight thru the complete disc. If they where it would be quick and easy, but they are not!
Are you:blush:

Let's stay on topic and keep the personal attacks to a minimum please.:nono:

:s4addict: -Audihead

[Nordschleife]

Originally posted by 8:29 RS6
Well Mr know it all, where is the coment on this?
My guess is that you thougt the hols was drilled straight thru the complete disc. If they where it would be quick and easy, but they are not!
Are you:blush:


Look, I have tried to remain civil, obviously a waste of time.

Don't bother responding to this post


R+C

[7:53 RS6]

Originally posted by Audihead
Let's stay on topic and keep the personal attacks to a minimum please.:nono:

:s4addict: -Audihead
You have a point there, but it was not that bad.(seen worse)
Me and nordo have ouer thing:argue:

[McBurn4ever]

The only thing I asked was about how how many pistons the S4 calipers has.
I did not ask for WW3, so stop it!