atikovi

Yes I know the negatives. This is just for cosmetic reasons since the car has large thin spoke wheels and I want the rear rotors to match the front's appearance. It's the base model with solid discs. This is the only place I found selling them at $149 a pair: https://brakeperformance.com/brake-r...nc-coating.php Any other places? And no, I don't want any that drilled AND slotted. Like I said, to match the front.

doni01

iTrader: (1)

I have been looking as well so I can match the fronts but haven't been able to find any. When I did my W220 rears I bought a set from STOPTECH drilled and they were great but haven't been able to find them for the W221...

BOTUS

wow - again

these cars do at least 155mph and the manu designed the braking system to allow you to stand on the brakes and safely stop

had they wanted to get you in to a massive crash with severe rear end instability, followed by the back overtaking the front and causing a 10 car pile up they would have fitted silly brakes at the back so it could do this easily.....

atikovi

Don't know where you're at but around here there is no place to do anywhere near 155mph and not sure what that has to do with the question anyway.

BOTUS

in Germany - they have sensible rules that do not allow individuals to play with things like this because its plain dangerous for ALL road users - check out TUV - it would be a very good idea for ALL counties to adopt such a simple and sensible rule

so you like the looks, but now everyone's else's life it at a higher risk than it was ??? under full on braking it takes very little modification to cause instability from the rear anywhere above 65mph

Car Modification Laws in Germany, car modifications are subject to the Straßenverkehrszulassungsordnung (StVZO) regulations, and vehicles must adhere to the Technische Prüfstelle (TÜV) standards

Motorists in Germany and Austria can only fit TUV-approved parts to their cars - the vehicle must remain roadworthy and operationally safe. After the conversion, the driving behaviour of the vehicle must not exhibit any critical conditions under normal operating conditions. This must be proven by an approval of the vehicle manufacturer or his authorised representative or by an expert opinion of a test centre, regarding all components with which the vehicle was converted. Under this condition, an entry is then made in the approval document (type certificate, individual approval notice or CoC document) at the office of the competent provincial government.

atikovi

Mercedes didn't use drilled rotors in the back because they probably didn't feel it added any benefits, seeing that 80% or so of braking is done by the front wheels. Saying drilled rotors cause instability is nonsense. Maybe if you only install one side.

doni01

iTrader: (1)

Botus,
No one is doing 155 here lol We are just looking to match the fronts since it kind of look stupid that the fronts are drilled but tue rears are not. It is pure cosmetic and has none to do with performance 🙂

kevm14

There is no way the ABS/stability/brake bias system is so unsophisticated that simply swapping to rear drilled rotors would make the car dangerous in a panic stop. I don't believe that at all.

juanmor40

I guess the same argument applies to the 4Matic system. You can change to any wheel/tire ratio and expect the 4Matic to still work and do not prematurely fail, correct? Apparently, real data does not show that.

kevm14

There is a difference between "malfunction" and "failure." And the real conversation is, when is a deviation from factory specs enough to cause either?

If drilled rear rotors definitely cause a heavy rear bias (they won't), then I could make the argument that you MUST run factory Mercedes brake pads and factory Mercedes everything because, who knows, it might just perform a little differently and cause a safety issue! Maybe I shouldn't be allowed to work on my own car, while we're at it. Obviously I don't believe any of that, and neither do you.

mikieb

They make good rotors. That is where I bought my cross drilled rotors for the front and back of my 07 w221. Just make sure you use ceramic pads to keep the brake dust at a minimum. I use the Hawk street performance ceramic pads.

BOTUS

in the first link is this for 300m solid discs ? the add doesn't seem to specify but gives a size 11.4mm thick?
some get 320mm vented

juanmor40

Definitely, no manufacturer wants us to modify their designs, god forbid something happens, and then we sue them for XYZ.

Two out of the discussions: Why MB does not even have a part number for those rotors? MB has made some iconic cars, so I assume they also have some auto-designers and consider the look and not only functionality. Perhaps we are better designers in both: looks and engineering.

On the "maybe we should not be allowed to work on these cars?" Perhaps is that why some parts come with this symbol. Either reminding to use a wrench and hat or that ONLY for certified mechanics (supposedly that implies knowing what they are doing).

atikovi

Have to question if you even understand the braking system after posting this. You can't just replace the solid discs with vented ones, and vented ones that are 20mm greater in diameter to boot. They won't fit the caliper opening.

BOTUS

in your first post rather than saying you wish to match the style of the front brakes - you said "I want the rear rotors to match the front's" I then missed the word "appearance" ....and moved too quickly to the second poster, who made the same comment but did not state anything about style or appearance - hence my interjection - that modifying the rears for the much more powerful brakes fitted on the front would be unwise

now re this question - You missed the question I was asking - as there are three sets of brakes fitted on the w221 - what I asked was on the link you gave what are the current brakes fitted on the car ?
as I can't see their site offering replacement disc for cars that come with vented rears, it would concern me - if they don't make it clear there are multiple choices what else don't they know ?



.

atikovi

Car is the base RWD with 300mm solid discs at the rear.

WHPH28

I have front and rear drilled.

No instability and no other issues. Drives and stops like a dream.

atikovi

That doesn't LOOK like a BMW.

The Thomas J

I don't know where you live, but in the NY Metro area, no one in their right mind is driving 155 MPH. On what road are we able to accomplish such a feat? I would LOVE to know.
OP will be just fine. Full disclosure I am planning on doing the same thing. I need new wheels and eventually will have to change my rear brakes, which seem to last forever on the W221.

The Thomas J

Yes, the sensible Germans, they have always looked out for the best interests of their fellow man.

BOTUS

these cars were meant to be driven like a mad man on autobahns where a lot of those roads remain unlimited - if you go to Germany its normal to find many drivers on their gentle commute to work doing 120mph - and I've been in E class Taxis where the guy was doing 145mph... once wound up these cars transform from lumbering semi-s that don't really make sense - and start to behave more like sports coupe's - and really come in to their own with the needle the other side of 130mph - everything starts to make sense the whole engine performance curve, the gear ratios, the steering and the handling come together in ways that they can't even contemplate below 90 mph...

so if you're not trying to get the other side of 120mph you've bought the wrong car ! its why Jags are a much better option in the USA

kevm14

I definitely agree that I've been impressed how this far feels over 100 mph. It transforms for sure. But I also enjoy it at normal speeds.

lkchris

It wouldn't surprise me if Zimmermann produced drilled rotors for your application.

I know for my Porsche Boxster they produce the standard not drilled and also offer drilled.

Last I looked at their website, they made a big deal regarding upgrading to drilled.

atikovi

Got them today and they look very nice. Match the front rotors perfectly.

Shadly1

That's nice. Are they coated?