RE: Carbon Brakes Set For New M5

[Zod]

DanBMW said:

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.

Well, they can win and always do, in that the reviewers love the cars and they sell, but that won't stop a bunch of forum moaners.

[GroundEffect]

thepony said:

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.

And since we know overall braking force is limited by tyre grip, and that large brakes are fitted to reduce heat and therefore fade, and that carbon brakes are much better at resisting/reducing both, the point stands. They shouldn't need to be as big.

Well you could extend that to the use of steel brakes - if braking effort is limited by tyre grip, why fit those massive brakes? Surely the size that is on them reflects the mechanical grip of the vehicle? Therefore switching to carbon brakes offers the same stopping power but for less weight penalty.

i knew carbon brakes:
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.

Yes, reduced brake fade is an obvious one. Reduced unsprung mass aids by the wheels settling quicker after a disturbance. It doesn't do much in steady-state cornering but it just means the car reacts faster, and more predictably when over bumps.

Carbon brakes don't offer any higher Coefficient of Friction.

[E38Ross]

Zod said:

DanBMW said:

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.

Well, they can win and always do, in that the reviewers love the cars and they sell, but that won't stop a bunch of forum moaners.

[DanBMW]

Zod said:

Well, they can win and always do, in that the reviewers love the cars and they sell, but that won't stop a bunch of forum moaners.

True.