Jim Will

the general consensus is that slotted rotors seem tohave the same "rumbling" felt/heard when braking until the speed reaches 40ish. (funny, I never noticed this until I read the responses to my post)
I noticed it today, paid strict attention to it. On an open interstate, got up to about 110, mashed on the brake. Car digs in abruptly, will easily engage the ABS at high speeds (engaged at over 90 when I tried this), I backed off the pedal slightly and felt the rumble. Not annoying, but noticeable until speed dropped to about 45. Did this 3 more times. same result. I may just have to live with it until these rotors wear out.
Just glad to know that I'm not imagining things

4Driver4

95% percent of the people that use them buy them for the looks. Drilled rotors are a bad idea. Slotted do facilitate gas disbursement but you really have to be into some heavy use to need slotting.

I run slotted rotors on the urS6 because I bought them with the intent to track it, which I have. The Miata, also tracked, might benefit from slotted rotors, but they are expensive given the minor difference...epecially when you factor in how little braking you actually need to do in the Miata.

All that said, I have no abnormal brake weirdness in the S6 either.

[[.:Uber-Stalker:.]]

One could think slotted & drilled would obviously be better than stock....

BoneDaddy

I can't say that I don't feel it on mine, but it was negligible, in fact it felt like about the same as many of the V6 cars I've driven at idle, not ehough to worry me or steer me away from slotteds, given their benefits. (for the record, I bought slotted simply because it was that or OEM for me and I don't like the OEM rotors)
it may vary fron manufacturer to manufacterer as well because I've felt zimmermans that felt much worse than my DBA

4Driver4

Slotted, yes. Drilled, probably not - unless you like cracking.

néné

I did post on the Benz forums, about any issues with x-drilled Zimmerman rotors, and there wasn't much of a reply.

I would never stay away from x-drilled or slotted because of this issue, given my track record with other manufacturers. I had purchased the Zimmerman purely for cosmetic purposes, as I can't see myself hauling *** in a 1994 E320, and requiring the benefits of said rotor types.

I had checked with 2 independent sources, and they checked the brakes, and said all was fine. It was at this point I decided to simply stay away from Zimmerman products (whatever rotors they make)!

You did not open a can of worms. It post was good in fact, which also put my worries to rest.

SinCityA6

<center><img src="http://pictureposter.audiworld.com/89898/misc_062.jpg"></center><p>I have combo drilled/slotted and have noticed they are a bit noisier when braking, but they do grab much better. Here are the rear rotors.

RLG

<img src="http://audifahrer.com/aw/misc/crack.jpg">

All Wheel Driver

and the brakes were perfectly smooth, with no noise or vibration at any speed.
it all has to do with the bedding in, I believe.
if you bed them in wrong, you'll get vibration.

hard stops repeated will only bring out hot spots and cause vibration.

this I say from experience. I bedded in rotors on a car I tracked following the traditional method and the first day out on track, the vibration appeared and never went away until I had the rotors turned.

The type of pad has alot to do with it. If it's an aggressive pad, it will make the vibration worse.

My wagon, which I never really did any bedding in procedure, just put them on and drove the car normally, never had a hint of noise or vibration.

These are just my experiences, yours may vary.

John/Jmess5

Not bad, just noisier...