D49

This forum has served as a highly useful source of information to me in the past. From what I can see, I am apparently the only person to have ever done this, and so I choose to share some of my knowledge here in the hope that it may help / inspire others. I found similar information about C & E class carbon ceramic brakes here, which initially pointed me in the right direction.

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A disclaimer: The following information serves only as a documentation of my own experiences. I do not guarantee the accuracy or completeness of the information. I do not guarantee that any parts lists provided are exhaustive or accurate, and please be aware that part numbers may change. I do not guarantee the fit of any parts to your particular car. I accept no responsibility for any harm or damage anyone using this information might incur. Should you wish to alter safety systems such as brakes, you do so entirely at your own risk. Before attempting any of this, consult a trained Mercedes-Benz technician and seek their advice. Should your country have legal requirements for brake systems, it is your responsibility to maintain compliance with them.

At an absolute minimum, you will need a good working relationship with a workshop that is fully a) EPC fluent b) WIS fluent for tightening torque values c) a very helpful dealer parts ordering department.

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Braking is one of the most critical part of the driving experience, and perhaps undervalued.

You have control over your own horsepower, acceleration, air conditioning, and sound system. You do NOT have control over apparently suicidal cyclists jumping in front of you. You do NOT have control over pedestrians talking to each other and walking into the road. You do NOT have control over the idiot in a M3 weaving through lanes who decides to jump in front of you at 70mph without any indicators while holding his phone.

Good brakes don't just allow you to drive faster on a race track. They may save your life. They may save someone else's life. They may keep you out of prison. It is perhaps the most meaningful upgrade you can do.

The R231 SL was sold with 4 different levels of braking packages, all made originally by Brembo.

"Standard brakes" for non-AMG engined cars
"H.D. brakes"/"Sport package brakes" for non-AMG engined cars (U28 / 950 & 951)
"Standard brakes" for AMG engined cars
"Carbon-Ceramic brakes" for AMG engined cars (B07)

These were as follows:

front: 342mm x 32mm vented, 320mm x 24mm unvented
front: 360mm x 36mm vented, 320mm x 24mm vented
front: 390mm x 36mm vented, 360mm x 26mm vented
front: 402mm x 39mm carbon, 360mm x 32mm carbon

About 80% of a car's braking power comes from the front wheel, and so the front discs are significantly larger.

Let me be quite explicit here. In sheer terms of stopping performance, for a one-off medium-speed hard stop: A steel rotor and a carbon-ceramic rotor that are the same size will perform near identically. They are however very different things.

A carbon-ceramic disc rotor of the same size as a steel rotor will be dramatically lighter. Every time your car accelerates, these rotors must be spun up to the same rotational speed as your tyres. This reduction in "unsprung weight" will improve handling.

Carbon-ceramic discs handle heat dramatically better. If you repeatedly brake, steel brakes will heat up and "fade" - to the point of major loss of braking performance.

For a higher speed stop, the extra friction that a carbon-ceramic disc can generate with the appropriate pads may be able to bring the car to a halt in shorter distance.

Carbon-ceramic discs are generally believed to be good for 100,000+ miles of use under road conditions, assuming no extreme abuse. They are also generally free from brake-dust that makes wheels look filthy.

But critically, the B07 Carbon-Ceramic system has a larger disc rotor than all other offerings. There is no comparable steel disc. The larger the rotor, the more braking force that it can apply, the faster it can stop and the more heat it can absorb for repeated braking applications.

My application was to a SL 500 / SL 550 that previously had the "H.D. brakes" U28 package. I do not know if it would be possible for a SL 350 or SL 400, but believe it would be highly likely. Checking EPC group 42 & subgroups 30, 45 & 90 would be essential. It would be possible for a SL 63 / 65, with the omission of the various parts marked * in the parts list below.

Careful examination of EPC will reveal that the SL 500 / SL 550 shares the identical front steering knuckles and wheel bearing as the SL 63 which fits B07 natively. However for the rear, while the angular contact bearing and wheel carrier flange are identical, the wheel carrier does have a different part number (EPC group 35, subgroup 75). This is shown in the diagram attached. I would HIGHLY recommend you check this for your own car. As such, there may be some concern that while the B07 front brake callipers would mount perfectly, an adapter or bracket may be required to mount the rear calipers should the mounting holes be different on the rear wheel carrier.

I am happy to report that this is NOT the case, and the rear calliper mounting holes were identical. As such, installing the callipers and rotors (with bolts tightened as per torque values provided in WIS) was an extremely straight-forwards task.

The following parts were used. Note: parts marked with * would be unnecessary for a SL 63 or a SL 65. Some minor unlisted bolts, brake paste (A0019899451) and brake fluid (A0009890807) were also used.

Front:
A2314211512 Bond Brake Disc
A2314211612 Bond Brake Disc
A2314212498 Fixed Caliper
A2314212398 Fixed Caliper
A2314210820 Brake Disc Covering Panel *
A2314210720 Brake Disc Covering Panel *
A0074207120 TS Disk Brake Pad
A2319057300 Brake Pad Wear Sensor x2
A2314200448 Brake Hose x2 *
A0004280673 Retaining Spring x2 *

Rear:
A2314230612 Bond Brake Disc
A2314230712 Bond Brake Disc
A2314231181 Piston Housing
A2314231281 Piston Housing
A2314230206 Brake Carrier x2
A0074209120 TS Disk Brake Pad
A2115401717 Brakepad Wear Sensor x2
A2314280035 Brake Hose x2 *
A0004280673 Retaining Spring x2 *

Misc. parts (not strictly necessary):
A0119902604 Cap Bolt with Socket x4
A0239978445 O Ring x2
N910105012010 Hex Head Bolt x3
A0199907901 Hex Head Bolt w Flange x4
A2204210171 Fit Screw x4

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However, there is one problem I discovered for doing this to a non-AMG engined car. The vast majority of R231 SL cars were sold with front 19"/ rear 19" wheels. A small number (SL 63 with forged wheel option, SL 65 default with forged wheels) have front 19"/ rear 20" wheels. However, the wheel styles available for the R231 differed between the AMG and non-AMG engined variants.

The reason for this is that B07 is offered as an option for the AMG variants, and the front caliper is just so large that it will impact some 19" front wheels! The previous AMG styled wheels I had on the car were approved by Mercedes-Benz for use on the non-AMG R231, and simply could not be mounted to the car.

As such, the only wheels which are guaranteed to fit with B07 installed as per the E/DP2Z/GS TUV document for the R231 are the following AMG styled wheels. Any other wheel, including aftermarket offerings will not necessarily fit over the front caliper. The offset of these wheels is a little different to the AMG styled wheels for the non-AMG engined R231, however they still do fit well within the non-AMG engine R231 wheel arches nicely with no interference with the suspension. They are also wider, which may mean a better contact patch with the ground and better rear grip especially under acceleration. If TUV certification is a legal requirement for your country, then for the SL 500 / SL 550 the wheel marked *** is approved.

A2314010000/A2314011902
A2314010100/A2314012102
A2314011800/A2314011900
A2314012200/A2314012300 *, **
A2314010200/A2314012302 *, **, ***

Note: Wheels with a * are forged aluminium alloy wheels, not cast. These are substantially lighter, even in spite of the extra width, than cast alloy wheels (~6.1kg / 13.5lbs all around lighter than my old AMG-styled set), but also significantly more expensive.

Note: Wheels with a ** are 20" rear, not 19". To ensure odometer/speedometer accuracy, you may well need to have the appropriate option code added to the VeDoc datacard of your car and the old code removed. This should be one of: 663, 697, 765, 766 or 767. Then your car modules must be coded to reflect this update. You may also require a new sticker that reflects the new 20" wheel size for your fuel tank flap of A2315841101 or A2315848401, but please double check this with your particular car.

Note: Wheels with a ***: These were the original forged wheel option for the R231 SL. They are made by Otto Fuchs AG for AMG, and are stunning in person. They were offered as an option on the SL 63 and were the default option on the SL 65. They were also offered on the SL 500 / SL 550 in some countries for some years as part of the "designo" package or the "mille miglia 417" package and as such are TUV approved. There is however a serious problem with the EPC / TUV description: colour codes 7X36 and 7X71 are described the wrong way around! The pictures listed on Mercedes ODUS are in fact correct. To be quite explicit: 7X71 has a polished silver surface with matte black internals. 7X36 has an all matte black design with a diamond cut rim edge strip. The descriptions & pictures for these wheels with himalaya grey (7X21, 7X70) are the correct way around. Mercedes is aware of this issue.

As for weight saving on the brake system, compared to the much smaller non-AMG "H.D. brake package" the rotors save ~16.5kg / 36lbs. The original "H.D. brake package" steel brake rotors weighed 41.8kg / 96 lbs! This difference would be even greater if compared against the larger rotors of the SL 63 / SL 65 standard brake package. Those were ~49.6kg / 109 lbs, so a disc rotor weight saving of ~ 24.3 kg / 53.5 lbs! However, this weight saving is offset by the larger and heavier callipers, as well as the heavier brake pads. I do not have a precise weight for these. It is therefore incorrect to say fitting B07 and swapping to AMG forged wheels will save ~ 22.6kg / 49.7lbs of weight for the non-AMG engined R231, or ~ 30.4kg / 67lbs for the SL 63. Close to that amount in unsprung weight is removed, but some additional weight is added from 1" larger rear tyres as well.

A note on pricing. The list parts price for the B07 system will be ~$/€/£ low 2X,XXX or high 1X,XXX. This can be reduced significantly, but the extent depends on your relationship with your dealership parts department. The list price on cast wheels (if necessary) is ~$/€/£ high 2,XXX or low 3,XXX, and the list price on forged wheels (if necessary) is ~$/€/£ high 6,XXX or low 7,XXX (without tyres). Again, these prices can probably be discounted. As for technician labour charges, the fitting of the parts is straight forwards (although should be performed with serious care!), but charges will reflect the amount of time required to go through EPC in great depth looking for all relevant parts. Unless you are extremely familiar with EPC and have your own Star system, I would recommend working with a trusted expert.

Finally, bedding in. McLaren, Ferrari and Audi all sell some variant of these same carbon-ceramic brakes which are made by Brembo-SGL, and all recommend a roughly similar bedding-in procedure, details of which can be found by a quick google search. Notably, BMW M also sells these brakes but recommends no bedding in procedure and there are numerous internet complaints and even possibly a lawsuit about the brake noise. I elected for a quick bedding in procedure and have no concerns of performance or noise under dry conditions. There is a little noise when moving from a stop in heavy rain.

I hope this helps!

Wolfman

Thanks for the very comprehensive guide! Although there wasn't any need for legal disclaimers; nobody will or could hold you liable

Most here will have sticker shock spending $20k+ on a brake conversion w. needed wheels. Most balk at the $9K for the CCB options on new AMG MB's without realizing just how well discounted that price actually is. Now if memory serves, the rotors/calipers from different AMG models will fit the SL (C63S & AMG GT; perhaps additional parts are needed) and I have seen complete kits occasionally for sale here and those are snapped up quickly. I thought that Racingbrake also had a CCB conversion kit for the SL but can't see that on the site. Was something like $15K or so...
For anyone thinking that this is pricey, a brake job for Porsche is $25k+ and that isn't even a retrofit!

I can highly recommend CCB's; they grip nicely and zero brake dust. And if ordered on an AMG new; they will be cheaper to maintain than steel rotors over time as MB charges handsome prices for their multi-piece steel rotors.. On a track these brakes are essential given how heavy MB's are.

I hope you enjoy your conversion! The car must drive must better now. We have the same wheels on our SL550 and I was surprised how the handling of the car improved due to their lower unsprung weight. Look great too!

D49

Wolfman,

I did see a photo of your car earlier, and it was very helpful to show me that the AMG styled wheels intended for the AMG engined cars would still sit nicely within the body of my car without protruding! I don't know what wheel colour code you opted for, but I must admit that obtaining mine was a horrible and lengthy experience due to Mercedes' incorrect description! I admit to not knowing about the history of Otto Fuchs KG before, and it was interesting to learn about their history and see just how light their wheel was. I have to say the styling matches the aesthetics of the car very well.

If memory serves, the option from factory for the R231 is somewhere around ~$/€/£ low 1X,000 to medium 1X,000 here. Some parts are indeed shared with other cars for either the front or the rear, including the S63, SLS, possibly the CLS 218?, but there is no other car that uses the complete set of same parts. Racingbrake does indeed offer a CCB kit, but it is a set of 4 CCB disc rotors identically sized as the "Standard Brakes" package for the AMG engined cars as a drop-in replacement. If you wished to fit that to a non-AMG engined car, you would still need to purchase all the "Standard brake package - AMG" callipers and additional parts on top of the Racingbrake kit.

Wolfman

The biggest issue is that MB simply doesn't offer CCB's for non-AMG cars, as stated. I am not sure where you are located (assuming US since you are referencing the SL550) and the CCB on a SL63 are only $8950 when configured. I had a chance to drive the SL63 with CCB's at Laguna Seca and was surprised just how well the car rode on the track. Obviously no speed demon due to weight but it as great fun and the brakes and ABC worked really well.

Your info will definitely help anyone looking for the upgrade. Happy motoring!