[Franzino]

Originally Posted by Arcanum-UK

For you and the other poster they might be OK for daily driving. That's great for you. However, for others the brakes are far from OK.

I've had to park the car up on three occasions, on the road, to let the brakes cool for a while.

The first on an alpine pass heading in to Switzerland from Italy (Grimsel pass). I had the wife in the car with luggage and it was a hot day, but I wasn't driving hard at all (note, wife in the car! ). The brake peddle was right on the floor at the end and had to leave the brakes 30-minutes to cool down. Two other occasions came from hard driving, late at night on British B-Roads (lots of tight corners and short straights).

If you're not doing repeated hard stops or mountain passes on hot days, the brakes are fine. For me, the 2NH upgrade is a significant reason for getting an M2C. Even for road driving. (I know I could retrofit 2NH, but I'm hoping the rear damping has been sorted and I want the increase power of the M2C with my warranty intact).

BTW, totally agree on the PS4's. Great tyres and have lasted better than the PSS's with more grip. I hope the M2C comes with them as standard.

The main problem is not the brake set-up (calipers / rotors) but the compound of the brake pads... If I have no complaints with the standard blue M2 brakes on the Nurburgring only by fitting different brake pads and uprated brake oil then the same brakes will do fine on hard street driving with only fitting different pads.

[Franzino]

Originally Posted by lemetier

The Retrofit Brake Kits are always significantly less than buying the components individually. Purchasing the kit and either swapping with someone who wants the red calipers or buying the Anthracite Calipers in addition to the full kit and selling the red ones on your own will be the logical choices.

If the price difference is indeed big and the price for the Red M Performance brakes kit is reasonable. Then it will be indeed the logical choice to go with this kit....even if I'm not a fan of flashy red calipers. When they get real hot the blue ones become green in time...will the red ones go pink?

[Artemis]

Originally Posted by Franzino

When they get real hot the blue ones become green in time...will the red ones go pink?

blue + yellow = green | blue + green = blue-green | blue + white = light blue
red + yellow = orange | red + green = brown | red + white = pink



And as regards ///M colors: how's Hockenheim Silver compared to the silver of the ///M emblem ?

[ChrisK]

Originally Posted by Artemis

blue + yellow = green | blue + green = blue-green | blue + white = light blue
red + yellow = orange | red + green = brown | red + white = pink

Attachment 1831642

And as regards ///M colors: how's Hockenheim Silver compared to the silver of the ///M emblem ?

Attachment 1831641

Artemis, do you know the RGB color value for the amber/orange color that BMW uses for lighting/backlighting?

[Artemis]

Originally Posted by ChrisK

Artemis, do you know the RGB color value for the amber/orange color that BMW uses for lighting/backlighting?

No, but likely you also know that you can toggle between amber/orange and white 'waterfall ambient lighting' radiating from the M2 roof near the rear view mirror + you can change the brightness:

• iDrive: "Settings" | "Lights" | "Ambient" | choose between "Classic" (amber/orange) and "Sport" (white).

[RedCarrot]

Originally Posted by Poochie

I don't care about the track, that twin turbo motor with its GT-R-like power potential; those BBK brakes are welcomed on the public streets... #ICantDrive55

Rotors and calipers are rarely the bottleneck on street emergency braking. The limiting factors usually come down to tire contact patch, tire compound, tire temperature, road surface, vehicle weight and its ABS capability. When one has to brake hard enough to cause skid marks - which the base brake kit is more than capable of doing - not even rotors the size of wheel barrel can help the vehicle stop in a shorter distance. Unless you are lucky enough to live near Deals Gap aka The Dragon where one could exercise the brakes hard constantly (esp going downhill where brake fade comes into play), I just don't see how the larger brakes benefit on public road driving. I envy the folks that have easy access to such roads and I would definitely prefer the larger brakes, too, if I were them.

If such test is conducted, it would be interesting to see whether the M2C can stop in a shorter distance than the M2 even with the larger brake, assuming they are wearing the same Michelin or Conti tires with similar tire wear. I would actually consider the M2 a small favorite in such test. In either case, I doubt the margin will be significant enough to be of any relevance.

[Poochie]

@RedCarrot

I get what you're saying; I am always braying to everyone that that tires are the only part of any vehicle that actually touches the tarmac, regardless if it's a Bugatti or Honda..

However, the M2C is heavier and more powerful vehicle, so the BBK are welcomed, regardless of how adhesive the tires might be..

[lemetier]

Originally Posted by Franzino

If the price difference is indeed big and the price for the Red M Performance brakes kit is reasonable. Then it will be indeed the logical choice to go with this kit....even if I'm not a fan of flashy red calipers. When they get real hot the blue ones become green in time...will the red ones go pink?

Between 40% and 60% less for the kit compared to each part ordered separately.

I honestly can't recall coming across any F10M showing the discoloration. I've seen it on quite a few M2/3/4 and it's caused most of the time by running the pads too near the wear limit on the track. Also have come across a few where the bleeder nipple leaked, and also from leaving solvent cleaners on the surface and allowing it to get hot.

[Advevo]

Discs are so much heavier rotational weight goes times 9.

If youre discs are 9kg heavier it feels youre carrying an extra passenger!

And most trackday tires are 18 inch.

You can better spend the money on an ap brake set and lighter discs then this very heavy system. It looks nice but it drives worse!

[Twt]

Originally Posted by Advevo

Discs are so much heavier rotational weight goes times 9.

If youre discs are 9kg heavier it feels youre carrying an extra passenger!

And most trackday tires are 18 inch.

You can better spend the money on an ap brake set and lighter discs then this very heavy system. It looks nice but it drives worse!

Agreed....rotational and unsprung mass is the devil. I have 50 plus track days on the M2 brakes with track pads, cooling ducts (DIY), SS lines and multiple tire set ups including Hoosiers and these brakes are awesome. Now, I admit I have not run a sub 8 at the Ring, but this new brake option is not a true M performance addition...is just looks really cool....which is fine but it's not a performance " upgrade ". The M2C is a nice car for the money, but BMW got lazy by raiding the parts bin and calling it a performance upgrade. I am still hopeful that the CS/CSL will truly move the needle.

[norMcal]

Originally Posted by Advevo

Discs are so much heavier rotational weight goes times 9.

If youre discs are 9kg heavier it feels youre carrying an extra passenger!

And most trackday tires are 18 inch.

You can better spend the money on an ap brake set and lighter discs then this very heavy system. It looks nice but it drives worse!

Originally Posted by Twt

Agreed....rotational and unsprung mass is the devil. I have 50 plus track days on the M2 brakes with track pads, cooling ducts (DIY), SS lines and multiple tire set ups including Hoosiers and these brakes are awesome. Now, I admit I have not run a sub 8 at the Ring, but this new brake option is not a true M performance addition...is just looks really cool....which is fine but it's not a performance " upgrade ". The M2C is a nice car for the money, but BMW got lazy by raiding the parts bin and calling it a performance upgrade. I am still hopeful that the CS/CSL will truly move the needle.

This is definitely a double edge sword. Bigger brakes are always welcome, but man that is a hefty weight penalty to pay. I swear I can tell the difference in the way my car drives just going to the lighter track wheels, and I think it is only a few pounds per wheel. I really wish Carbon discs would last longer and were more reasonably priced, because that would solve all problems................and they don't squeal like a school bus when street driving.

So what do you think a comparable, lighter AP Racing BBK would be and would cost?

[Twt]

Originally Posted by norMcal

This is definitely a double edge sword. Bigger brakes are always welcome, but man that is a hefty weight penalty to pay. I swear I can tell the difference in the way my car drives just going to the lighter track wheels, and I think it is only a few pounds per wheel. I really wish Carbon discs would last longer and were more reasonably priced, because that would solve all problems................and they don't squeal like a school bus when street driving.

So what do you think a comparable, lighter AP Racing BBK would be and would cost?

It may be a fluke, but I have been running PFC08 pads and they make a lot of noise on the street....then I installed my new slotted Stoptech two piece front rotors with new pads and the street squeak is reduced about 75%....may be temporary

[Karmic Man]

Originally Posted by Advevo

Discs are so much heavier rotational weight goes times 9.

If youre discs are 9kg heavier it feels youre carrying an extra passenger!

And most trackday tires are 18 inch.

You can better spend the money on an ap brake set and lighter discs then this very heavy system. It looks nice but it drives worse!

Wrong maths. Rotors are much closer to the centre of the hub therefore the multiplier effect is not anywhere close to 9. Much more like 2-3 times the net weight saved. Even rims have a higher multiplier effect than rotors.

If people want to save weight because of rotational inertia they should not opt for wider (heavier) tyres as tyre being furthest out to the centre of the hub has the highest multiplier effect.

The slight impact in handling is a fair trade off for a greater heat dissipation ability from the big bake system.

[norMcal]

Originally Posted by Twt

It may be a fluke, but I have been running PFC08 pads and they make a lot of noise on the street....then I installed my new slotted Stoptech two piece front rotors with new pads and the street squeak is reduced about 75%....may be temporary

Pretty sure it will squeal eventually. It always comes and goes, dependigng on the amount of embedded pad material on the rotor. After a track event is is usually pretty quiet for a while.

I suppose your new rotors are quite for now, because they are not worn in yet.
BTW, I switched to PFC08's recently and am not a fan. Not sure why so many love them. I think the Hawk HT-10's have way more bite. I guess it differs depending on driving style.

Originally Posted by Karmic Man

Wrong maths. Rotors are much closer to the centre of the hub therefore the multiplier effect is not anywhere close to 9. Much more like 2-3 times the net weight saved. Even rims have a higher multiplier effect than rotors.

If people want to save weight because of rotational inertia they should not opt for wider (heavier) tyres as tyre being furthest out to the centre of the hub has the highest multiplier effect.

The slight impact in handling is a fair trade off for a greater heat dissipation ability from the big bake system.

Also, calipers, which are part of the weight gain of the bigger brakes, aren't part of rotational mass, obviously.

[Advevo]

I don t get why will you put 17kg more weight on youre performance car. It s the wrong way around.

I drive with pagid yellows allround and have no problems. Brake hard and short. And after 5 hotlaps i do a cooling down lap. I have had zero problems and don t need heavier brakes for sure. It is a nice option for the posers.

[Poochie]

After track usage, I'm pretty sure we're going to hear stories like "My Red BBK are now Hello Kitty Hot Pink"

[eeyang92]

From what I gather, the only point of a BBK is for increased cooling (besides aesthetics) - wouldn't a brake duct produce the same, if not superior, effect? As others have noted, as long as ABS is kicking in, your limitation is your tires, not your brakes?

[DelGriffith]

Originally Posted by Advevo

I don t get why will you put 17kg more weight on youre performance car. It s the wrong way around.

I drive with pagid yellows allround and have no problems. Brake hard and short. And after 5 hotlaps i do a cooling down lap. I have had zero problems and don t need heavier brakes for sure. It is a nice option for the posers.

I'm confused.
I do track days, certainly not as much as others here, but I'm out a few times per year. Like others, I have been very pleased with my factory brakes, with the mandatory pad swap and fluid upgrade. My question is this (provided that I have driven the M2C exactly as many times as all others here...), aren't we likely to REALLY appreciate the BBK as we try to slow the heavier car coming into corners carrying more speed (S55)? I'm really hoping the new power gets us moving faster despite the added weight, and the BBK will end up being an appreciated upgrade.

[Karmic Man]

Originally Posted by eeyang92

From what I gather, the only point of a BBK is for increased cooling (besides aesthetics) - wouldn't a brake duct produce the same, if not superior, effect? As others have noted, as long as ABS is kicking in, your limitation is your tires, not your brakes?

Repeated heavy use of the brakes in a short period of time for prolong period can lead to brake fade as some members here had experienced. A brake duct will certainly help but might not be sufficient. Once brake fade starts it will take much longer for the ABS to kick in or if at all.

With a BBK you have the extra cooling capacity plus the extra mechanical leverage from clamping the bigger pads onto the bigger rotors so you don't have to work your brakes as hard. Therefore it has a higher tolerance against brake fade. In addition all the auxiliary parts (pistons, rotors, pads, brake fluid...etc) will last longer.

[RedCarrot]

Originally Posted by Karmic Man

Wrong maths. Rotors are much closer to the centre of the hub therefore the multiplier effect is not anywhere close to 9. Much more like 2-3 times the net weight saved. Even rims have a higher multiplier effect than rotors.

If people want to save weight because of rotational inertia they should not opt for wider (heavier) tyres as tyre being furthest out to the centre of the hub has the highest multiplier effect.

The slight impact in handling is a fair trade off for a greater heat dissipation ability from the big bake system.

Given the added weight is on the outer diameter of the rotor that is the size of 15-16 inch wheel, I had say the rotational mass multiplier is much closer to the generalized 9X than 2-3X.

It’s a necessary evil for those that truly need it so I am not speaking against it universally. I would just recommend that one should exhaust other brake improvements that do not incur weight penalty before resorting to larger brakes. So often people automatically attribute brake mushiness to overheated rotors, when in fact the causes are overheated brake fluid and brake line expansion. OEM brake pads are typically of low quality (or designed for street-ability) because they don’t meet the eyes and don’t cross the mind of regular car buyers. Upgrading those three things on the base brake kit should provide ample braking performance except for truly hardcore track drivers on demanding tracks.

It’s easy to overlook the base so-called “M” brake kit is already a BBK in itself at 380mm (15”). It’s used on M3/M4 that has an even higher powered S55. I suppose it’s all moot if the larger brake kit is indeed standard on the M2C. I just think it should have been a $1,000 option instead and lower the price increase from $4,500 to $3,500.

And, yes, people should also not get wider tires than what the car needs. It’s a balancing act, like everything in life.

[CSBM5]

Originally Posted by RedCarrot

Given the added weight is on the outer diameter of the rotor that is the size of 15-16 inch wheel, I had say the rotational mass multiplier is much closer to the generalized 9X than 2-3X.

The difference in the radius of gyration between the original M2 brakes and the enlarged ones comes nowhere near that level of change. Even if the radius of gyration increased the same amount as the disc (which it doesn't, it's less), it's value increased by 5%. The hysteria surrounding this topic in this forum is beyond anything that makes engineering sense.

Also, people are quoting the increase in "brake weight" and assuming it's all in the disc which is of course false.

[infinitekidM2C]

i think we'll need to graph this out