RE: Carbon Brakes Set For New M5
Discussion
Zod said:
In the UK, I tend to agree. For Germans who like to drive at 150mph+ on the Autobahn, whcih entails much braking from that speed down to less than half, they will be more useful.
You could have a point but you still won't be continuously braking to warrant the use of carbon brakes... and then you have the question of if you haven't been using them and they aren't up to temperature and get up to 155mph and have to do some heavy braking, will they be as effective? I know it's not quite the same but I've nearly caught out by racing pads left on after track daysJulian M said:
But it seems everyone has forgotten, this is optional. For years I have seen on lots of sites people complying that the m brakes are not as good as they could be. This is defiantly a good step forward.
So is buying a set of high-performance brake pads and thereby saving yourself thousands.For 99 percent of owners its about bragging rights, I have to have special "Taste the difference" brakes as my car is so fast and I am such a driving god 
If you are using a car with six piston 400 odd mm, grooved, vented, disks on the road to the point they arent adequate then perhaps you are driving a bit too fast ?
If you are using a new M5 on track, sure it would be great fun if expensive but perhaps an old Mx5 with a cage and super grippy tyres might be more appropriate ?
BMW proved perfectly good kit, across the range, but they will sell you are super duper Business, Pro, Nappa, Carbon or whatever version for more money, I suspect they dont make much money on a bog spec 116 at say what, 18/20 grand and possibly make more on these brakes, Carbon being the most abundant substance in the universe and all that, now they are developed I cant see why carbon brakes are so expensive ?
I am however glad there is stuff like this, just dont try to justify it to a female who wants to spend that five grand on something else as its really shaky ground.
If you are using a car with six piston 400 odd mm, grooved, vented, disks on the road to the point they arent adequate then perhaps you are driving a bit too fast ?
If you are using a new M5 on track, sure it would be great fun if expensive but perhaps an old Mx5 with a cage and super grippy tyres might be more appropriate ?
BMW proved perfectly good kit, across the range, but they will sell you are super duper Business, Pro, Nappa, Carbon or whatever version for more money, I suspect they dont make much money on a bog spec 116 at say what, 18/20 grand and possibly make more on these brakes, Carbon being the most abundant substance in the universe and all that, now they are developed I cant see why carbon brakes are so expensive ?
I am however glad there is stuff like this, just dont try to justify it to a female who wants to spend that five grand on something else as its really shaky ground.
I dont see why anyone is questioning this. It is an Option for people who want to use their M5 on track, authbahn, fast road driving or indeed bragging rights.
If I was to spend £10k on options I would rather this option than most other "Driving aids" you can spec these days - lane departure, night vision, auto parking etc etc.
If I could afford to spend £80k on a (rapidly) depreciating and stunning new M5, the cost of these brakes could I suspect be easily justified.
If I was to spend £10k on options I would rather this option than most other "Driving aids" you can spec these days - lane departure, night vision, auto parking etc etc.
If I could afford to spend £80k on a (rapidly) depreciating and stunning new M5, the cost of these brakes could I suspect be easily justified.
Toffer said:
It will be a costly upgrade and even costlier to service. Think around £5K+ to replace...
+1 - the reason I would always opt for regular discs - most modern discs are more than up to the task of what I'd need them for anyway (and yes I realise that carbon brakes have a longer life than their metal counterparts) - Carbon ceramics in a race car? Yes why not, in a road car for 99% of driving e.g. cruising around the m25? I think not alexpa said:
If driven as spec intend, it needs them. I dought the standard brakes would last a track day.
I'm sure you're absolutely right, although BMW don't build their large saloons as track cars and anyone with that kind of cash who wants a track car would be much better shopping elsewhere.Good news. Complaints about recent M cars chocolate brakes are all over the interwebs.
A set of carbon ceramic brakes do offer superior stopping power and virtually never fade.
Unless you do something stupid like grind the pads down to the metal and damage the discs they should last as long as the car.
A set of carbon ceramic brakes do offer superior stopping power and virtually never fade.
Unless you do something stupid like grind the pads down to the metal and damage the discs they should last as long as the car.
Whilst I would agree that M5s are certainly not natural track day cars I had many happy hours in my E34 on tracks around the country. The spec brake setup would definately not last a track day but I found the main problem to be the pads and fluid, not the discs or calipers. When fitted with high temperature pads and fluid I could stand on the brakes all day long without fade, although the discs would get rather hot (see picture). By far the greatest improvement in braking performance, however, came when I switched to running on slicks. Luckily ex BTC slicks fit my car perfectly and were very cheap. 
British Beef said:
J4CKO said:
now they are developed I cant see why carbon brakes are so expensive ?
Do some research online and you will quickly understand that is is still hugely expensive, energy hungry and time consuming job to make Carbon composite discs. How much is actual cost compared to BMW options cost ?
They are NOT carbon/carbon brakes as fitted to F1 and DTM cars, therefore there's no requirement to get them up to a working temperature of circa 400 degrees before they start working efficiently . . .
http://www.f1technical.net/articles/2
In true carbon/carbon installations (such as in F1 and DTM) the disc is sacrificial. When brake temperatures are not controlled adequately in a race, the disc runs hotter, oxidises and thus wears out quicker (this manifests itself as large plumes of black carbon dust billowing from the wheel/hub assembly during a high speed stop on an F1 car)
Ultimately the disc wears to the point whereby it fragments and "explodes".
SGL has made the all PCCBs fitted to Porsche cars since 2001. (they've merged with Brembo in the last 3-4 years IIRC) The PCCBs are formed of a base substrate on to which two wearing faces (the face of the disc the pads bears on) are bonded.
http://www.porsche.com/microsite/technology/defaul...
The wearing faces are thin (less than .5mm) They wear and as they do so they become more susceptible to overheating, when they overheat they then start to delaminate. Furthermore they are prone to stone damage when a car ends up in a gravel trap. Once the surface has been damaged or chipped, delamination will follow.
The first 996 GT2s fitted with PCCBs were prone to the heat management issues. Porsche AG rapidly ammended its claims "suitable for any use and will last in excess of 110,000 miles" and added the caveat "dependant on use".
The first owners were shown "goodwill" by Porsche AG when the discs started to fail (back in 2001 a set of PCCB discs and pads was circa £30K (now the discs cost approximately £3.5K +VAT each)
Later "victims" were told the discs had failed due to "driver abuse". Lawsuits were issued but to no avail . . . .
Porsche and SGL had however realised there was an issue and this seemed to centre around cooling. Contrary to popular belief, carbon ceramic discs are not particularly good at dissapating heat, but their performance is superior to steel discs IF the heat management issues can be controlled.
Porsche and SGL tried several different internal venting arrangements in an effort to improve durability. They met with some success, but solved the issue by fitting larger diameter front discs to the front of the 997 PCCB equipped models (in the case of the Gen 1 997 GT3 it used 380mm dia front PCCBs, whilst the steel equivalent was 350mm dia . . .
PCCB failure :
They should look like this :
Knowing that Porsche and SGL were experiencing issues with their PCCBs, Surface Transforms
http://www.surface-transforms.com/
started to manufacture an alternative. http://www.systemst.com/products/product-overview
It's manufactured using a different process to the SGL Brembo product. For a start it homogenous and thus the surface of the disc can be machined in the event of minor damage.
Unfortunately there have been cases of owners removing wheels off PCCB equipped cars without using the(recommended and supplied) guide studs. On removing the wheel from its centering spigot, it's dropped onto the edge of the PCCB and chipped it with catastrophic and expensive results.
The SGL discs are currently fitted to the Koenigsegg CCX. I also have a set on my 996 GT2.
Contrary to what some have said, the benefits in unsprung weight are very clear, though maybe on an overweight barge like the new M5, the benefits of the SGL Brembo discs may not be so noticeable.
Rest assured their performance will be impressive and the cars steering response will be improved as a result of their fitment
http://www.f1technical.net/articles/2
In true carbon/carbon installations (such as in F1 and DTM) the disc is sacrificial. When brake temperatures are not controlled adequately in a race, the disc runs hotter, oxidises and thus wears out quicker (this manifests itself as large plumes of black carbon dust billowing from the wheel/hub assembly during a high speed stop on an F1 car)
Ultimately the disc wears to the point whereby it fragments and "explodes".
SGL has made the all PCCBs fitted to Porsche cars since 2001. (they've merged with Brembo in the last 3-4 years IIRC) The PCCBs are formed of a base substrate on to which two wearing faces (the face of the disc the pads bears on) are bonded.
http://www.porsche.com/microsite/technology/defaul...
The wearing faces are thin (less than .5mm) They wear and as they do so they become more susceptible to overheating, when they overheat they then start to delaminate. Furthermore they are prone to stone damage when a car ends up in a gravel trap. Once the surface has been damaged or chipped, delamination will follow.
The first 996 GT2s fitted with PCCBs were prone to the heat management issues. Porsche AG rapidly ammended its claims "suitable for any use and will last in excess of 110,000 miles" and added the caveat "dependant on use".
The first owners were shown "goodwill" by Porsche AG when the discs started to fail (back in 2001 a set of PCCB discs and pads was circa £30K (now the discs cost approximately £3.5K +VAT each)
Later "victims" were told the discs had failed due to "driver abuse". Lawsuits were issued but to no avail . . . .
Porsche and SGL had however realised there was an issue and this seemed to centre around cooling. Contrary to popular belief, carbon ceramic discs are not particularly good at dissapating heat, but their performance is superior to steel discs IF the heat management issues can be controlled.
Porsche and SGL tried several different internal venting arrangements in an effort to improve durability. They met with some success, but solved the issue by fitting larger diameter front discs to the front of the 997 PCCB equipped models (in the case of the Gen 1 997 GT3 it used 380mm dia front PCCBs, whilst the steel equivalent was 350mm dia . . .
PCCB failure :
They should look like this :
Knowing that Porsche and SGL were experiencing issues with their PCCBs, Surface Transforms
http://www.surface-transforms.com/
started to manufacture an alternative. http://www.systemst.com/products/product-overview
It's manufactured using a different process to the SGL Brembo product. For a start it homogenous and thus the surface of the disc can be machined in the event of minor damage.
Unfortunately there have been cases of owners removing wheels off PCCB equipped cars without using the(recommended and supplied) guide studs. On removing the wheel from its centering spigot, it's dropped onto the edge of the PCCB and chipped it with catastrophic and expensive results.
The SGL discs are currently fitted to the Koenigsegg CCX. I also have a set on my 996 GT2.
Contrary to what some have said, the benefits in unsprung weight are very clear, though maybe on an overweight barge like the new M5, the benefits of the SGL Brembo discs may not be so noticeable.
Rest assured their performance will be impressive and the cars steering response will be improved as a result of their fitment
GroundEffect said:
doogz said:
GroundEffect said:
bern said:
With their improved braking performance, isn't their a case for fitting smaller discs and therefore smaller lighter wheels?
That's not how carbon brakes help. Carbon brakes don't actually provide any higher stopping power (which is still fundamentally limited by tyre grip), they just reduce unsprung mass and are less prone to fading under heavy use.help reduce brake fade - good for spirited driving on the roads/track
help reduce unsprung mass - does this make it handle alot better? - and if so how can someone explain this - apart from being quicker to accelerate and brake how does it affect cornering?
that tyre grip/road surface - contributes to braking but i didnt realise this is fundamental but when you think about it it is right.......try braking in the snow....
i didnt realise that carbon brake discs have same friction coefficient as steel brakes is this right?
I think larger discs help to produce a larger torque to oppose the wheel rotation. As the larger the disc is the further away the calipers from the wheel hubs. Moment = force ^ distance from the pivot.
That is my thinking anyway.
British Beef said:
I dont see why anyone is questioning this. It is an Option for people who want to use their M5 on track, authbahn, fast road driving or indeed bragging rights.
If I was to spend £10k on options I would rather this option than most other "Driving aids" you can spec these days - lane departure, night vision, auto parking etc etc.
If I could afford to spend £80k on a (rapidly) depreciating and stunning new M5, the cost of these brakes could I suspect be easily justified.
10K on brakes?If I was to spend £10k on options I would rather this option than most other "Driving aids" you can spec these days - lane departure, night vision, auto parking etc etc.
If I could afford to spend £80k on a (rapidly) depreciating and stunning new M5, the cost of these brakes could I suspect be easily justified.
A decent secondhand caterham is 20K
But i just don't get the M5 as a high performance track weapon due to its 20 tons of toys.
If i was spending 80K I'd have a brand new BMW estate, a Caterham R400 and a cover car trailer which would be way more fun then a M5
I think why i don't like the M5 is it has a complete lack of focus. A Fiat panda is a more focused car then an M5, a panda is focused on being cheap transport. An M5 with its toys and carbon brakes is trying to be everything.
thinfourth2 said:
British Beef said:
I dont see why anyone is questioning this. It is an Option for people who want to use their M5 on track, authbahn, fast road driving or indeed bragging rights.
If I was to spend £10k on options I would rather this option than most other "Driving aids" you can spec these days - lane departure, night vision, auto parking etc etc.
If I could afford to spend £80k on a (rapidly) depreciating and stunning new M5, the cost of these brakes could I suspect be easily justified.
10K on brakes?If I was to spend £10k on options I would rather this option than most other "Driving aids" you can spec these days - lane departure, night vision, auto parking etc etc.
If I could afford to spend £80k on a (rapidly) depreciating and stunning new M5, the cost of these brakes could I suspect be easily justified.
A decent secondhand caterham is 20K
But i just don't get the M5 as a high performance track weapon due to its 20 tons of toys.
If i was spending 80K I'd have a brand new BMW estate, a Caterham R400 and a cover car trailer which would be way more fun then a M5
I think why i don't like the M5 is it has a complete lack of focus. A Fiat panda is a more focused car then an M5, a panda is focused on being cheap transport. An M5 with its toys and carbon brakes is trying to be everything.
the whole "trying to be everything" is what the M5 has been for over 25 years now; and it does a truly remarkable job at that, too.
keep up at the back!
Are people seriously questioning what an M5 is about? As has been said its doing exactly the same as it has always done its a PERFORMANCE (or super) saloon. Its to get as close to a super car as you can get with room for 5 and luggage.
The amount of contradicting comments on all the M5 stories it seems BMW can't win these days.
The amount of contradicting comments on all the M5 stories it seems BMW can't win these days.
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