chrisvr6

Does everyone else have cross-drilled rotors on their e350's?

lfranklin

No. The sedan comes in two flavors: luxury & sport, the sport has "sportier" suspension and cross drilled rotors.

Johnny Mo

Yep...'11E350 4M, P2 and Sport Pack (minus Driver Assistance Pack)

FEGELEIN

correct, my old man just picked up a 350 sport and it's drilled.

Ctrl+alt+Elite

I wish the rear rotors would have come drilled as well

lfranklin

2/3 of a car's stopping power is on the front, thus the larger rotors. Cross drilling on an E is for the "sporty" illusion, and it makes the rotors more prone to cracks. Real racers don't usually drill them, slots are more common.

PHML

I concur...debating if I should buy rear cross-drilled to match the fronts.

mafialink

yes

grane

That's why two piece brakes are common on racers so it makes it easy to change disks and they can choose lower unsprung weight. Some racers still like the drilled rotors but they crack and they last one race and get s-canned. Some ideas die hard....

I had slotted Racing Brakes on my NSX and I hope they make a two piece solution for the CL55. Smart engineers there.

Stock AMG brakes are awesome, but I'd like the 2 piece rotors when I have to replace them. Check out Racing Brakes.

Super Steve

Hi, guys! I have a E350 and was looking over the net to find the best deal to get new Rotors and pads. I found an online shop based in Ontario and they have Canadian manufactured brake kits at a verry competite price. They offer a quality custumers service and it was a pleasure to talk to real brake profesionnals. The website is: https://www.crossdrilledrotors.ca/

Johnny Rad

From the "it doesn't matter department" or "meaningless trivia:"

If I recall correctly, Merc calls our non-AMG sport front rotors either perforated or ventilated; no cross-drilled. I've looked for my sources, but can't find anything...

Anyone else recall the same?

NickTH

Just came back from 2-day Corvette Performance driving school near Vegas.
Their fleet of 80+ uses stock brakes (non-drilled) & gets flogged hard daily. The instructors says no problems with heating nor fading at all.

So I doubt if our E series gets that much racing abuse for need to upgrade to drilled rotors...

Mud

I've got the boy racer drilled rotors on my sport. When the time comes for brakes I plan to replace them with solid rotors and akebono pads. I believe the drilled are slightly larger than the solids to account for loss of swept area. Other than looks on these cars they serve no useful purpose.

DJ Hellfire

Yeah but your average E350 owner isn't gonna heat the rotors enough to crack them just daily driving. Even over time.

DJ Hellfire

It would be perforated. Nearly every modern car uses ventilated front disks and many large, more expensive vehicles, like the E also use ventilated rear disks.

DJ Hellfire

Yeah, but even for street they still help to keep a nice rough surface on the pads.

Mud

Not really. The theory about the outgassing from holes/slots is that they should allow for debris to be removed from the surfaces, keeping the pads cleaner and smoother. Common issues with them are usually related to less mass = more heat, combined with many inferior products out there. I did find that the Zimmerman/OEM rotors are cast with the holes, so the heat treating is uniform throughout the rotor, many aftermarket are drilled later which impacts the heat treatment and can also cause small chips at the edges of the holes. So be careful about price vs. quality.


Also, regarding warping vs cracking, put a laser temp gun on a rotor when you get home, you will be surprised how hot they not only get but how much heat they retain, even from regular driving. The heat sink part can be an issue if they hit cold water/rain, which can cause warpage.


I say anyone can use what they like but I prefer the solid mass rotors, good quality pads, and a brake system with regular fluid flushes. Other than looks IMO I just can't see a rational justification for drilled. Ventilated is another story, yes most everyone has them and they do a good job of capturing airflow into the rotor surfaces.

DJ Hellfire

I'm not talking about gassing or heat dissipation. I'm simply talking about the chamfered edges of the holes that helps prevent glazing on the pad surface. You ever notice the slight grinding noise when you stop? This is from the holes shaving the pad surface a bit.

Mud

Well I am including gassing/heat into the mix because that's part of the consideration. Chamfered edges in the holes are not to prevent glazing, they are on the better quality rotors to prevent hot spots at the leading edges of the holes.

Any noise I hear is the same for both front (drilled) and rear (solid) rotors and I would not describe it as grinding. Holes in rotors are not like a cheese-grater, they don't shave off parts of the pads. If they did pads would only last about 5-10K miles and in fact proponents of drilled rotors describe pads lasting longer, so I don't know the basis of your theory.


Noise is directly related to surface condition of the rotor and especially pad material, not holes. Semi-metallic pads can be on the noisy side, especially when cold and/or when first driven after the car has been parked due to accumulation of surface rust and any debris left on the pad. First few brake applications are essentially wiping the surfaces and building some heat into the rotors.


Anyway, there's not much more to add to all this. It doesn't really matter to me to be "right", I'm only trying to look at some evidence pro/con.

DJ Hellfire

Ok, not trying to debate about it, but slotted rotors have the same/similar edge as the slots which provide the effect in referring to. Look it up.

But the real evidence would be that engineers smarter than you and I are putting these rotors on the cars from the factory (MB, Ferrari, Maserati, Porsche, etc), so it's pretty obvious that they won't be a danger nor inferior in performance, whether use them for show or function. And I would highly doubt changing to a solid rotor alone would provide better stopping on street use. Now if one were to be tracking a car then obviously it would be wiser to use an actual track setup. Anyway, my point is, if MB used drilled rotors from the factory, you're not gaining anything by going OEM-replacement solid, unless you're going with aftermarket parts in efforts to save money. In another words don't reengineer the vehicle (unless you're modding).

Mud

Lol I have looked it up. Slots vs holes are not the same but I understand your point about many high performance cars supplied with the drilled rotors. At the same time many heavy vehicles - trucks, full size cars, etc are solid rotors. MB uses both drilled and slotted from the factory so it's personal preference, not re-engineering on the E's that are provided with both, like the sports and the lux versions. Last word to you my friend.

rediesel

Here is some brake ****. 14.2" slotted, ventilated, perforated, 2-pc rotors with 6-piston calipers.

Alex.currie44

The wagon I just traded had drilled fronts but not the rears.

joesrepsol

"brake ****"... love it.