Get Cross drilled rotors for my 300E??? - PeachParts Mercedes-Benz Forum

mike690003 · #1 06-17-2003, 02:14 PM

Anyone have cross drilled rotors on their 300E or any car? I see pairs on ebay for $115 and am looking into a set.I can get a stock set of rotors for $150(all four) The cross drilled ones on ebay are Brembo and look pretty cool under a nice set of wheels. Are there any drawbacks to buying them?

MTI · #2 06-17-2003, 08:58 PM

Be careful about buying cross drilled rotors. The biggest downside is having them crack and stress at the drill holes. Having a rotor go to pieces is not a good thing when you need to brake. The second downside to cross drilled rotors is that they can eat up pads faster.

Also beware, since Brembo boxes don't mean that they haven't been drilled out by someone else.

Badinfo · #3 06-18-2003, 12:26 AM

You can also buy crossdrilled rotors from fastlane. I have never used them however.

gsxr · #4 06-18-2003, 11:09 AM

I would not recommend drilled rotors. I used to buy them myself but quit after having them crack at the holes. The proper way to have holes in the rotor is to cast them with holes, like OE Porsche brakes. For us mortals, stock or slotted discs are much better. I've used slotted ATE PowerDiscs with no problems, although some people didn't like them. Better bang for the buck is good brake pads, the top choices seem to be Porterfield R4-S ($225/set), or Textar "Yellow Box" Euro-compound pads (~$75/set).

Your 300E has pretty small brakes all around, same as my 300D's. You can upgrade to bigger E420 stuff if you can afford it, about $400 for the fronts and $300 for the rears with used calipers. This will mostly just add fade resistance though. Full details on W124 brake sizes are here:

http://www.meimann.com/docs/mercedes/124_brakes.pdf

I'm in the middle of doing this myself, I bought all the parts, just haven't installed them yet. Here's a photo of my new E420 calipers all painted & ready to install:

http://www.meimann.com/images/mercedes/W124_brakes/calipers_painting.jpg

mike690003 · #5 06-18-2003, 11:32 AM

So the Brembo ones on Ebay are not cast with holes??
Are They just drilled in??

gsxr · #6 06-18-2003, 11:55 AM

Yep. Rotors with cast holes will cost you BIG bucks and are not available, AFAIK, as bolt-on replacements. You'd need the full Brembo setup from Movit.de with Brembo calipers, etc to get the cast-holed rotors... not worth the $3-$4k unless you have a 500E and take it to the racetrack, IMO. Good pads, and/or the E420 upgrade, should be plenty. Some folks get the drilled rotors for looks alone, which is fine if you aren't hard on your brakes,

mike690003 · #7 06-18-2003, 11:59 AM

Well I have to admit. The cross drilled rotors look sweet. And, I'm not a hard braker. Hmmmm??? Just might get the cross drilleds after all.

Badinfo · #8 06-18-2003, 01:16 PM

For regular street driving, you will probably never be able to put the discs under enough stress to crack them.

shanta · #9 06-18-2003, 02:27 PM

gsxr,

By cast do you mean chamfered? (not sure if they mean the same thing) If so then KVR sells chamfered cross drill rotors. I use them on my E5.

Badinfo · #10 06-18-2003, 02:42 PM

I think chamfered rotors are ones that are slotted as well. Of course, this is just based off of my understanding of the word chamfered.

shanta · #11 06-18-2003, 02:46 PM

Quote:

Originally posted by Badinfo
I think chamfered rotors are ones that are slotted as well. Of course, this is just based off of my understanding of the word chamfered.

Not sure how true that is because mines are chamfered but I do not have slots, as I opted for only cross driller, not cross drilled and slotting.

My rotor have a "beveled" type hole.

Badinfo · #12 06-18-2003, 03:37 PM

ahh ok. That makes sense because chamfered is supposed to mean: To cut off the edge or corner of; bevel.
To cut a groove in; flute. haha, so I guess its in referenced to the beveled holes. Necessary to keep the disc from eating the pads like a cheese grater. Hrrrmmm, I don't know of those are cast though...

gsxr · #13 06-18-2003, 03:59 PM

I don't think I said chamfered, did I? Hmmm. Didn't mean to (oops). Anyway, as Badinfo said, chamfering is beveling an edge. Normally the leading edge of new pads are chamfered lightly to aid bed-in, and drilled holes are chamfered to help avoid the inevitible cracking. True cast-hole rotors are VERY rare and usually only found on exotica like Porsche, Lambo, Ferarri, with mega-buck OE Brembo brakes.

Slotted/grooved/fluted rotors help with outgassing and water problems (driving in bad rain), and normally have no negative side effects. Other folks say none of this is necessary, and plain old OE rotors are just fine! FWIW, after doing much research, I bought OE dealer rotors for my brake upgrade. They are Blanchard ground, which most aftermarket rotors are not (don't ask me to explain what that is, I'm not sure!), and have a nifty anti-corrosion protection that is non-oily and doesn't need to be cleaned/wiped off before installation. Kinda cool stuff. Got a great deal from Rusty, whom some of you know intimately, the rest probably order from FastLane...

Regards,

shanta · #14 06-18-2003, 04:03 PM

Quote:

Originally posted by gsxr
I don't think I said chamfered, did I? Hmmm.

No need to be a a$$. I just asked a question, but I see I was better off not doing that.

As I stated I was not sure if they are they same thing, or not, but thanks anyways for your answer.

gsxr · #15 06-18-2003, 04:13 PM

Shanta, no offense or sarcasm was intended! I wasn't sure if I said that or not - my memory ain't what it used to be, even from stuff I wrote hours ago! Friends? (extending hand)

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