i thought it peculiar [as in strange] that MBZ put non drilled rotors on the rear of the R231 with standard brake package with drilled rotors on the front. Like everyone else, the excessive brake dust on the rims is a giant issue for me with factory pads. . . I was therefore planning a full brake job to get rid of the soft factory pads, opting for Brembo Ceramic pads front and rear with new Brembo rotors all around. .
At first I was going to drill the new rear rotors myself, [ I have a machine shop] but I noticed that pre-drilled 'sport' rear rotors were just $20 more than non-drilled. . That got me thinking and I did a little research on the measurement specs for the sport rear rotors, and compared them to standard rotors. .
Short story is that the factory sport rotors are identical in design to non-drilled rotors.

Anyway, I ordered Brembo part number 09.b743.51 from Autohaus Ariz for $209.93 for a pair. . Went right on with no issues. . The fit was identical to standard non drilled rotors.
Total Brembo Parts, front and rear rotors and pads was $541, sourced thru Ebay. . If you're interested check Rock Auto for best prices but they didn't have the rear ceramic pads when I was ordering.

It was a full day job in the driveway with a floor jack, one wheel at a time for a 78 year old guy. . My local independent service shop quoted me for 4 hours - $720 Labor at $180 hr, and the dealer was $880 at $220 per hour.
The fronts were easy with no surprises, but the rears require you going into the service menu on the dash computer to have the rear calipers retrace the parking brake assembly. . directions on You Tube.

Now, I hope there is a noticeable reduction in brake dust. . On my test drive there was no difference in stopping. . I'll update this thread when i get the pads bedded and fully seated.

 

Good for you! Quite an accomplishment for me to just get off the ground once I'm down. Glad the rears are the same size for both the standard and HD Brakes.

 

Don't know how it is in the states, but in the UK if anyone does this they really should inform their insurer of the modification.

 

One month update. . . after 100 miles there is a major reduction in visible dust on the rims while the braking has had no
noticeable change with normal street driving. What dust there was seemed to be lighter in color and easily washed off.

 

Good decision. I swapped out the OEM pads for Power Stop carbon ceramic pads immediately after purchase. I have the AMG Sport Package so drilled rotors F&R. 90% reduction of brake dust.

 

Brilliant! thanks!!

 

A machinist like you can do some incredible metal fabrication. Do you think you could drill out solid rotors, and still retain the precision balancing to avoid any out of balance vibration?

 

Drilling the holes is not complex and if the locations are precise and consistently concentric I've found they do not effect balance, However if you are asking if anyone could change a solid disc to an internally vented rotor the answer is no- they must be cast with the hollow core and the substructure to make them strong.