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Cross Drilled vs. Slotted Brake Rotors vs. OEM

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Old 12-13-2008, 07:23 AM
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vasculardoc
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Default Cross Drilled vs. Slotted Brake Rotors vs. OEM

Hi All,

I'm about to replace my 90 C4 front rotors (current ones worn out) and am looking at whether I put standard solid OEM part, slotted or drilled rotors on the car. Are there any particular thoughts from people with experience of differnt types of rotors.

I'll also put some decent pads on as well, and am looking for recommendations from people in a similar driving situation. Pagid vs. anything else that people have experience with.

I use the car as a daily driver and don't do any track work, and want to know that when I stomp on the pedal with my little boy in the car with me it will stop no matter what, but also that the setup is useful for round town driving without being too "grabby" (ie I want progressive brake torque)

My car has standard 16" D90 wheels, so unfortunately big reds probably aren't an option ($$ as well).

Look forward to hearing peoples thoughts.

Mark
Old 12-13-2008, 07:40 AM
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elbeee964
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Hi Mark,

Solid disks are the way to go, without a doubt. Drilled don't gain much, pragmatically, and introduce the trouble of inter-hole disk cracking. (I'll leave to others comments on slotted disks and pads.)

Good luck on this change. If you're doing it yourself -- a satisfying and dollar-saving measure -- there are some DIY threads around here, I believe.

Cosmetically, don't forget to paint those disk hats well. Otherwise they'll quickly rust (like a 40-year old Fiat).
Old 12-13-2008, 08:46 AM
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demonfish
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Originally Posted by elbeee964
Hi Mark,

Solid disks are the way to go, without a doubt. Drilled don't gain much, pragmatically, and introduce the trouble of inter-hole disk cracking. (I'll leave to others comments on slotted disks and pads.)

Good luck on this change. If you're doing it yourself -- a satisfying and dollar-saving measure -- there are some DIY threads around here, I believe.

Cosmetically, don't forget to paint those disk hats well. Otherwise they'll quickly rust (like a 40-year old Fiat).
i respectfully disagree.

They will rust like a 1 year old fiat.

Get your facts straight

for standard driving, go OEM, for track work go drilled.

As your road, standard will be fine, i'd go with standard pads too.

Big reds would be a huge waste of money, the standards are more than capable of locking the wheels, the bigger is just for more heat reserve on track, IMHO.

I run the bigreds but on OEM pads, until i get a bit quicker.
Old 12-13-2008, 10:36 AM
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dfinnegan
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Cross drilled rotors were on my car when I bought it. They were installed at 29k miles and I bought the car with 36k miles. I drive my car year round in New York. Last year I let the car sit for a couple of weeks. There were ~68k miles on it. The rotors rusted. The rears rusted so badly that I had to replace them! I suspect poor quality parts were the problem. Note that they were not worn as there was plenty of meat still on the rotors.

The point being, if you choose cross drilled ensure that you get good quality parts and not modern cheap materials.
Old 12-13-2008, 10:59 AM
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Gasser
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Ok here is my opinion with some experience behind it. For a street only car, any of the above options will be great as you will only use about 10% of your brake capability there. Aftermarked drilled rotors on the track are much more likely to crack if driven hard and very hot. Lots of stress risers around those drilled holes. I have cracked a set after only one track session. Factory drilled rotors seem much better and on my 993 I use the drilled for racing and they hold up perfect.
For a street car I would choose what looks great to you as they all will perform well and stop you every time. As for your pads, go with a good street compound as you won't get a race pad hot enough to stop well on the street. I don't know if padgid sells a street compound but hawk does and I use them on my street cars. Its the HP plus pad and they don't dust bad, have great initial torque and last fine. I even use them on my wifes 7000 pound Excursion diesel with slotted rotors. No more warping from that setup. They are great.

YMMV

Jeff
Old 12-13-2008, 11:05 AM
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deep_uv
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I've never seen a solid rotor with cracks. Just sayin....
Old 12-13-2008, 11:21 AM
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CWay27
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If you drive it daily then got with the look you want to give it. Aftermarket cross drill will be fine and you'll never get enough heat in them to crack in between holes. If you track a little then I suggest to either go with oem cross drill or better yet slotted. As for pads, I suggest to go with oem.
Old 12-13-2008, 11:42 AM
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demonfish
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my car came with cheap and nasty aftermarket drilled.

two slow laps of the ring, they were warped.

avoid cheap brakes!
Old 12-13-2008, 12:04 PM
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Indycam
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Some people really like the looks of a cross drilled rotor .
If you want the looks without the problems ,
buy a set non drilled and take them to a machine shop ,
have a set of dimples drilled in just the outside .
Just drill down to the wear limit .

Its just an idea , I have not done it , I don't know if someone else has .


http://www.frozenrotors.com/store/2134%20FZR
http://www.frozenrotors.com/store/2127%20FZR
Old 12-13-2008, 01:10 PM
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race911
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Originally Posted by deep_uv
I've never seen a solid rotor with cracks. Just sayin....
Sure they can. Not in a street situation, of course. But they can given enough track abuse. Now I will say this does not refer to a 964 rotor that I've ever seen.
Old 12-13-2008, 01:44 PM
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Originally Posted by CWay27
Aftermarket cross drill will be fine and you'll never get enough heat in them to crack in between holes.
I disagree, I have cracked rotors with just street driving. I read somewhere that all drlled rotors crack due to thermal cycles. Even the factory used and still use them as disposable items.
Old 12-13-2008, 02:55 PM
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I'm just about to replace my 993TT (drilled) OEM rotors due to cracking after 1/2 dozen track events.
I'm thinking slotted not drilled.
Old 12-13-2008, 07:16 PM
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deep_uv
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Originally Posted by race911
Sure they can. Not in a street situation, of course. But they can given enough track abuse. Now I will say this does not refer to a 964 rotor that I've ever seen.
Agreed that they can. I didn't say they couldn't, I just said I haven't seen one. I've seen lots of drilled ones that are cracked. And yes, I was referring specifically to 964 rotors.
Old 12-14-2008, 07:00 PM
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vasculardoc
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Thanks for a bunch of useful responses....I'm probably going to go with solids based on the group feeling and the fact that durability is a primary concern, and that looks aren't that important (and anyway.....what could possibly improve the looks of a 964 ;-) ).

Thanks for everyones input.

Mark
Old 12-14-2008, 07:06 PM
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Originally Posted by deep_uv
Agreed that they can. I didn't say they couldn't, I just said I haven't seen one. I've seen lots of drilled ones that are cracked. And yes, I was referring specifically to 964 rotors.
I agree. It is very unusual and very difficult to crack solid rotors that are internally vented. Take a close look at the structure and the thickness of the rotor. Not impossible, but unusual.


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