Cross Drilled Rotors - are they that much better?

[e34.535i.sport]

1. I have to get new rotors and wonder if the cross drilled or slotted are that much better than the OEM for road use.
2. If my pads are still fairly new should I replace them if I replace the rotors?
3. If answer to #2 is yes, what type of pads should I get? Semi-metallic?

Some people think that the drilled rotors can tend to warp more easily than the normal ones... I think slotted is a good compromise from what I've read. I will be getting some ATE slotted rotors next time mine need replacing but haven't had any problems with the standard ones so far.

I will always change discs and pads together, but I know a lot of people who have changed one or the other and not had problems. If the pad hasn't worn evenly on the old disc then it will have a negative effect on the new one... Personally, I'd do both.

[vping]

1. I have to get new rotors and wonder if the cross drilled or slotted are that much better than the OEM for road use.
2. If my pads are still fairly new should I replace them if I replace the rotors?
3. If answer to #2 is yes, what type of pads should I get? Semi-metallic?

[Qube]

Ask yourself why you are looking for better than OE first... then in my opinion:

1. nope
2. if they are fairly new (80%+), then keep them, check the sensors though while you're there
3. OE

Personally, I got cross-drilled on the e34 and e39, and PBR ceramics, but just because I like the look. There is noticably better stopping power as well, but justified for the price over OE.... mmmmmmmm... probably not. Depends on your driving.

[Tiger]

Wow! That's dirt cheap for a set of 4 rotors... Go for the slotted/drilled rotors. They are much much better than solid rotors.

I had crossdrilled rotors for 10 years... one set that lasted 10 years. I had it cut once but doesn't last that much longer. About 70,000+ miles on that rotors. Mine was pure cross drilled and tons more hole that the one you linked.

The only thing about crossdrilled rotors is that it does drone like airplane brake on landing when you stop hard... but not that loud. For me, I love it because it tells me how hard I am braking.

With this link you show me, I think it will be just as quiet as the ATE slotted rotors. I have slotted rotors for 7 years now... I find it a great compromise... stops just as good and quieter.

Yes! Change the pads. Go with Akebono Euro (ceramic type)... if you want super bite brake pad, then I would go with PBR Metal Master. Use same pads for all 4 corners.

For racing, then I have no experience... I do know you need something else... Like Hawk, etc.

[vping]

Found these on ebay. NO affilication whatsoever. Just looking for rotors is all.
I wonder what everyone thinks.

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=011

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=011

[bad_manners_god]

Found these on ebay. NO affilication whatsoever. Just looking for rotors is all.
I wonder what everyone thinks.

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=011

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA:IT&ih=011

I have Drilled Rotors on the E34 from ebay, and for 140$, they're very inexpensive compared to a single rear rotor.

And there is noticeable stopping power increase.

[Qube]

Don't know about those ones. I've used Zimmerman and Magnum w/o issues.

[SnakeyesTx]

I drove my E34 pretty hard in corners, being a 525 with a slushbox it wasn't fast so I focused mainly on handling and braking on that car. I went with cryo-treated Cross-drilled AND ventilated rotors. The drilled holes basically help brake pad to rotor surface gases escape where as the slots help with "Bite" and supposedly help in cooling. The cooling theory has always been under debate so I can't verify that part for sure.

I ran ceramic OE style pads I bought from the local parts house and after driving with it for a year, the pads had very little wear, a TON of bite and really confident stopping power. The little roar from the slots didn't take long to get used to, but you can really feel it bite especially in a panic stop. As some have stated here, you can get all 4 on e-bay for less than buying just the two front OEM rotors.



I definitely plan to get the same setup for my E39 as well.

*** note about your question 3 : after a year, my ceramics had very little wear and very little dusting on the Basketweave rims, however the ceramic pad material is a harder composite, which wears rotors faster. My x-drilled/vented rotors actually had a little "lip" maybe 1/4 of a mm where the pad didn't touch the very outer edge of the rotor. I was told that when running rotors like these, you should really go with organics so the pad takes the majority of the wear instead of the pads eating up your expensive rotors. I'll probably consider "Green-stuff" racing pads next time around just to see how well they work, last and how little they dust. (If I'm not mistaken organics dust the rims the worst)

[healtoeit]

1. I have to get new rotors and wonder if the cross drilled or slotted are that much better than the OEM for road use.
2. If my pads are still fairly new should I replace them if I replace the rotors?
3. If answer to #2 is yes, what type of pads should I get? Semi-metallic?

As qube said... depends on your driving... I run them because I track and autocross... On the street the difference is really not noticeable unless you are really pushing the car.
I like to replace pads and rotors...if I were you I would go w/ oem rotors or an = b/c you have good pads (i'm assuming they are oem). oem+oem=great braking, I've seen guys run them for track days, nothing at all wrong with that combo.

[dauchande]

1. I have to get new rotors and wonder if the cross drilled or slotted are that much better than the OEM for road use.
2. If my pads are still fairly new should I replace them if I replace the rotors?
3. If answer to #2 is yes, what type of pads should I get? Semi-metallic?

What I've read says that slotted/cross drilled are better, but you have to make sure they were cast that way rather than drilled after the fact. Cross-drilled especially can cause cracking of your rotors if not done right.

Personally, I'll be putting on some frozen power slots on mine, these are slotted.

http://www.frozenrotors.com/products/power-slot-cryo/

As far as pads, I can't seem to get a straight answer on that, everyone seems to have a different opinon on what's the best. I've heard PBR, Axiss, Pagid as well as others are good. I've heard good things about ceramic pads, but don't have practical experience with them (yet).

Hopefully that'll help a bit.