About to order a new RS4 but what about ceramics ?

[Graeme4130]

For everyday driving, standard brakes are more than good enough
Ceramics don't actually provide any improvement in braking, they just don't overheat and fade on sustained track work like the standard ones do

I've seen some older ceramics with a worse co-efficient of friction rating than traditional pads.
The overall improvement though is that with less rotational inertia of the wheel assembly more braking force can be used to slow the car.

Not wanting to be argumentative, but I think your physics are out there. The rotational force, which is what the friction property of the brake is reducing, is the result of the rotational force of the cars forwards energy (unless the brakes sole purpose is to lock the wheel and the car continue forward, in which case your argument's valid)
There is a benefit to braking efficiency, but it'll be almost immeasurable as it's only the overall vehicle weight saving the ceramics have on the car
For suspension movement, then yes, unsprung weight allows a tyre to track the road better due to decreased reaction times of mass movement

Besides that, they still look the bollocks and I wish I'd spec'd them on my car to be honest

[RIV]

I think the ceramics are well worth the extra cash, I was covering ground very quickly the other day when someone pulled out of a side road in front of me, my car stopped on a six pence!!! I've been really impressed with mine, still can't believe 2 people have done this since I've owned riv, they must be blind it's not as if my car doesn't stand out

[Graeme4130]

I think the ceramics are well worth the extra cash, I was covering ground very quickly the other day when someone pulled out of a side road in front of me, my car stopped on a six pence!!! I've been really impressed with mine, still can't believe 2 people have done this since I've owned riv, they must be blind it's not as if my car doesn't stand out

So blinded by the blueness, that they can't see anything and pull out

[RIV]

So blinded by the blueness, that they can't see anything and pull out

maybe the blue just trips them out into confusion

[adsgreen]

For everyday driving, standard brakes are more than good enough
Ceramics don't actually provide any improvement in braking, they just don't overheat and fade on sustained track work like the standard ones do

I've seen some older ceramics with a worse co-efficient of friction rating than traditional pads.
The overall improvement though is that with less rotational inertia of the wheel assembly more braking force can be used to slow the car.

Not wanting to be argumentative, but I think your physics are out there. The rotational force, which is what the friction property of the brake is reducing, is the result of the rotational force of the cars forwards energy (unless the brakes sole purpose is to lock the wheel and the car continue forward, in which case your argument's valid)
There is a benefit to braking efficiency, but it'll be almost immeasurable as it's only the overall vehicle weight saving the ceramics have on the car
For suspension movement, then yes, unsprung weight allows a tyre to track the road better due to decreased reaction times of mass movement

Besides that, they still look the bollocks and I wish I'd spec'd them on my car to be honest

So would your proposition be that a 1000kg wheel attached to a 500kg sprung mass stop exactly the same as a 10kg wheel attached to at 1490kg mass?
Granted slightly exaggerated

But the principle is that I order for brakes to stop a car the first need to slow the wheel assembly to a speed slower than the road speed. If you have a heavy wheel this is more difficult than a lighter wheel.
A heavy wheel is more likely to overwhelm the brakes than a lighter one.
It's an oversimplification but the outcome is true - a light wheel assembly will reduce braking distance over and above that of a spring mass.

[Nickyboy]

Amar had issues with his ceramics on his V10 RS 6. Think his username is MrV10. Could be worth asking him what happened with his.

[Graeme4130]

[

So would your proposition be that a 1000kg wheel attached to a 500kg sprung mass stop exactly the same as a 10kg wheel attached to at 1490kg mass?
Granted slightly exaggerated

But the principle is that I order for brakes to stop a car the first need to slow the wheel assembly to a speed slower than the road speed. If you have a heavy wheel this is more difficult than a lighter wheel.
A heavy wheel is more likely to overwhelm the brakes than a lighter one.
It's an oversimplification but the outcome is true - a light wheel assembly will reduce braking distance over and above that of a spring mass.

I'm prepared to stand corrected, but I still think your physics are wrong there, and that the mass energy in your first scenario is exactly the same as your second, albeit through exaggeration
Your argument in the second paragraph is, again, only valid if your objective is to 'slow the wheel to a speed slower than the road speed' (ie lock the wheel up), which is exactly what efficient braking is trying to avoid, and that the force generating the rotational mass is defined by the entire weight of the moving object (ie the 1500kg in your first paragraph)
The improvement only comes from where the unsparing weight saving affording by ceramics allows the wheel to track over bumps quicker

I think we need to agree to disagree on this one or we'll be here all day. The long and the short of it is that the ceramics are a better option than the steels, but I think potentially very expensive if something goes wrong
They look great though and I wish I'd ordered them just for the reduced wheel cleaning
Fwiw, I'll be ordering my next day to day car with them budget allowing

[adsgreen]

when you threshold brake a wheel it is travelling slower than the road speed (even if only be a small amount) .
Modern street tyres operate at peak efficiency where the tyre's tread is moving around 15% slower than the road speed (it's no different to slip angles when cornering). in this scenario where the wheels are not locked the mass of the wheel becomes very important into how overall efficient the braking can be. The main point is that it is easier to control the wheel with the brakes if it's lighter as it more responsive to braking input.

Tbh on a road car the effect is going to be minimal with the choice an condition of tyres the main factor.

As for ceramics- well... If you live in the mountains or venture on track then I could see it but bloody expensive for something overall won't work any different to steel in 99.9% of situations.

Oh - previous post I was quite drunk

[Graeme4130]

Ceramics are so good nowadays too, you'd not know they were different during day to day driving
Did you ever drive any of the early ceramic brakes 8 or so years back ?
I drove one of the early Porsche turbos with ceramics and you'd have no brakes at all and then half a mm more pedal and you had your face in the windscreen

The brakes on the V10+ are still a little bit 'grabby', but you don't notice it after a bit - The ones I've tried on RS4/6's are very good indeed

[adsgreen]

Ceramics are so good nowadays too, you'd not know they were different during day to day driving
Did you ever drive any of the early ceramic brakes 8 or so years back ?
I drove one of the early Porsche turbos with ceramics and you'd have no brakes at all and then half a mm more pedal and you had your face in the windscreen

The brakes on the V10+ are still a little bit 'grabby', but you don't notice it after a bit - The ones I've tried on RS4/6's are very good indeed

Yeah - really weird sensation.
Also when they got wet!!! I was used to unassisted brakes so I knew wet weather could be an issue but bloody hell... I recall one moment coming off the motorway at a reasonable speed approaching the junction/roundabout and pressing the brake pedal... Resistance was fine and perfectly normal but absolutely and I really really mean absolutely no braking! Proper clench moment and then the water must have been scrapped off and followed by the traditional faceplant on the windscreen.



I think the more recent on

[AMB]

In short get them for all reasons you've heard they're good, and more.
Be careful braking hard from big speed; they can scare the feck out of ya at first with the STOP rate.
Silas what do you reckon?

[RIV]

Silas what do you reckon?

Very impressive

[Moschop5]

Silas what do you reckon?

Very impressive

x 2

[Moontang]

My view is that this is more a case of whether you can afford/stomach the £4k or not.
For the vast majority of driving you're likely to do in your car, there is absolutely no benefit.
So, for me, unless you're going to own the car long term and/or get through particularly high mileage during your ownership or spend time on the track. I think the £ v performance/longevity factor doesn't quite add up. If they were £2k, for the functional benefit and unquestionable aesthetics, it would be a no brainer.

[Ricky]

Very impressed with all the comments guys, and my opinion isn't any different from the majority here....... Yes of course I want them, and yes I have no doubt how good they are. The only thing that worries me is the cost of replacements.

In an ideal world Audi state they should do approx. 190000 miles with normal road driving, so I'm never going to have to replace them for wear, but having googled problems, some people have been left with massive bills that Audi wouldn't cover. Waiting for my dealer to come back to me, as he told me they would be covered without doubt for the first three years, but year four and year five he wouldn't commit to, so we are awaiting official word back from Audi. The cost at the time of purchase doesn't annoy me if I was sure that was the only time I'd have to dip into my pocket with regards the brakes during my time of ownership. Maybe thats just wishing thinking !