Quick brake rotor question
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Senior Member
Joined: Jul 2010
Posts: 386
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From: Wisconsin
CL550 1976 450 SL
Quick brake rotor question
2007 4Matic, non-sport. Need to replace rotors and pads. Std. MB rotors are "blank", I found. Current ones (second set, I'd guess--74000 miles) are drilled.
What value is there and/or is it worth it to go to drilled? Slotted? Drilled and slotted.
Or, for plain ol' driving are oem blanks just fine?
Lastly, all I need are pads, rotors and two wear sensors, correct?
Thanks.
What value is there and/or is it worth it to go to drilled? Slotted? Drilled and slotted.
Or, for plain ol' driving are oem blanks just fine?
Lastly, all I need are pads, rotors and two wear sensors, correct?
Thanks.
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From: Planet Earth
S500
True ..optical-wise its nice to have holes in your disks..
Brake-surface wise I would tend to stick to plain ..
Unless your planning on a disk-diameter/caliper upgrade to have the same sq.inch surface, which would imply larger wheels and tires to fit as well; if you do not already have that ..
Brake-surface wise I would tend to stick to plain ..
Unless your planning on a disk-diameter/caliper upgrade to have the same sq.inch surface, which would imply larger wheels and tires to fit as well; if you do not already have that ..
Last edited by marthyh; Jun 3, 2012 at 11:41 AM.
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1999 E320 & 2008 S550 Designo
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From: Chico, CA
S55K AMG
In the old days, the brake pad material did have gas build up that could float the pads against the rotor, nowadays, the pad material does not have that same gas build up, so drilled rotors are purely cosmetic and do run the risk of cracking because the holes are now a weakness in the metal. Slotted rotors do have some performance gain, but at the expense of pad life. Unless you are tracking your car, blanks are perfectly fine and will hold up to almost anything that you throw at them for street use.
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1999 E320 & 2008 S550 Designo
For looks only???
In the old days, the brake pad material did have gas build up that could float the pads against the rotor, nowadays, the pad material does not have that same gas build up, so drilled rotors are purely cosmetic and do run the risk of cracking because the holes are now a weakness in the metal. Slotted rotors do have some performance gain, but at the expense of pad life. Unless you are tracking your car, blanks are perfectly fine and will hold up to almost anything that you throw at them for street use.
Kinda hard to swallow that one.....
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From: Planet Earth
S500
Boost 420 is right about the 'gassification of solids' etc. bc of new materials, slotted still used to keep the surface clean etc.
But mistertonyn and Chris the Swede ,have point as well: a lot of different car-manufacturers like ,Porsche ,Ferrari etc. make holes in their disks as well..
Except, when there is serious racing going on; Nascar/F1 they would prefer to have Surface rather then holes..
I guess as usual, the engineering truth ,is a solution with compromises and for performance-street cars that might as well be slotted/drilled and it is not so bad marketing wise to have the optical aspect as well.
But mistertonyn and Chris the Swede ,have point as well: a lot of different car-manufacturers like ,Porsche ,Ferrari etc. make holes in their disks as well..
Except, when there is serious racing going on; Nascar/F1 they would prefer to have Surface rather then holes..
I guess as usual, the engineering truth ,is a solution with compromises and for performance-street cars that might as well be slotted/drilled and it is not so bad marketing wise to have the optical aspect as well.
Last edited by marthyh; Jun 5, 2012 at 06:07 AM.
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From: Clifton, NJ
96 and 08 911 turbos
It was at some point ingrained in sports/high end luxury buyers that the brakes on high performance or high end cars should have holes or slots.
May there be a modicum of benefit if you are doing 30 minute sessions on a road course and really getting a ton of heat into the brakes? possibly.
For even semi-crazy street driving..no difference.
I'll say this: If you are driving hard enough to notice a difference from slotted/drilled rotors, you'll have boiled the brake fluid a while ago.
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From: Chico, CA
S55K AMG
That is exactly what I am telling you. Here's some info, there are countless articles exactly like this.
http://www.marcusfitzhugh.com/CLK/DIY/brakecdrill.html
Additionally, here is the rotor off of the SLR, notice any cross drilling there
Surface area dissapates heat, vane design and airflow to the rotor are far more important then some little holes that actually take away from the overall surface.
Last edited by boost420; Jun 5, 2012 at 03:41 PM.
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From: ChiTown
06 Carrera4
Although many arguments seem compelling, until someone runs two rotors made from same material, agains each other measuring braking ability and heat extraction , I'm going to take arguments one way or the other with a grain of salt.
Just going to stay with what's on the car and not spend money going one way or another.
One thought comes to mind is that Benz prides it self on safety and if my front rotors being drilled are less effective I would think they would stay with solid disks.
Just going to stay with what's on the car and not spend money going one way or another.
One thought comes to mind is that Benz prides it self on safety and if my front rotors being drilled are less effective I would think they would stay with solid disks.
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From: Chico, CA
S55K AMG
If you want to continue putting crossed drilled rotors on your car because you think that it adds some type of additional safety, i have some beach front property you might be interested in. I run them on my amg, but i do not have a false illusion that they add anything other than a look that i like.
Last edited by boost420; Jun 6, 2012 at 12:07 AM.
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From: ChiTown
06 Carrera4
If you want to continue putting crossed drilled rotors on your car because you think that it adds some type of additional safety, i have some beach front property you might be interested in. I run them on my amg, but i do not have a false illusion that they add anything other than a look that i like.
Keep your smart alek comments to your self along with your property jack
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From: Clifton, NJ
96 and 08 911 turbos
the brakes are fine, drilled or not.
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