DAS/STAR Registered Owner
Join Date: Jun 2014
Vehicle: '06 SLK55
Other Toys: Legos, Play Doh, TinkerToys, Hotwheels
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030 Big Brake Rotor Upgrade To 360mm Now Doable!
Ive been watching the SLKW threads and finally, the aftermarket is now starting to fill out the 340mm and 360mm high performance full floating brake rotors used on the front of the '55.
For those of us with the 6 pot caliper standard (as I have on my '06) and no 030 option, we have been limited to a 340mm brake rotor. While all model year 171's with 030 have the exact same six pot caliper as the early '55's, the 030 gets a larger 360mm rotor.
Later '55's without the 030 got a four pot calipers with a smaller rotor as well so if you've been wondering about an upgrade, you will want to read on.
So the only difference between the 030 six pot caliper and the early '55 six pot caliper is a bracket that moves the caliper out 10mm. That's all it takes to properly space for the larger 030 rotor. Of course Brembo won't offer the bracket by itself and neither does Merc. So unless I buy the complete 030 brake caliper set (ka-ching), I'm stuck.
And for those who would upgrade to the 6 pot calipers, the ones used on the 340mm rotor are more readily available both new and used since they are more common on other models besides the early '55. The caliper that fits the 360mm rotor, not so common.
One suggested machining up a set of 10mm spacers to install between the 340mm caliper bracket and the caliper to space it further out. But using spacers, the caliper bolts could potentially loosen. And if that happens it that could ruin my whole day.
So while my '55 is up in the air for a few other goodies, a buddy of mine is CNC machining me up set of brackets out of 4043 moly steel to duplicate the ones found on the 030. That will move the caliper out with no worries about spacers coming loose.
And with the 360mm Brembo rotors on Amazon for about $600 a pair (instead of the $1400 the stealership wants), this upgrade makes perfect sense. Especially considering my 340mm rotors are toast.
That said, it seems that the OE/Brembo rotors are about 2/3's as hard as the better aftermarket brands.
The Brembo is about 145 on the Brinell hardness scale. The $1000 Stoptech rotors are around 171. The $1300 RacingBrake rotors tested were 196 and 193, so about 34% harder than OE and 14% harder than Stoptech. That explains why my OE rotors were toast at 40k miles.
Harder Brinell translates into longer life, but potentially twice the expense. I'll post more once the brackets are done.
Last edited by jbanks15; 12-26-2017 at 08:21 PM.