Hey guys what is better slotted or drilled brake discs?? cheers

 

blanks > slotted > drilled

 

2 piece blanks > 2 piece slotted > 2 piece drilled > blanks > slotted > drilled

 

+1. Youll never see me run slotted on my car. Although the chance of abnormal warpage/cracking may be minute, the possibility is there.

-Matt

 

I am to worried about that as well. I wont ever have slotted brakes on my car either.

 

well why no slotted rotors??

 

Enlighten me on this guys. I thought the peurpose of slotting/ cross drilling rotors was to reduce brake fade caused by gas accumalation under hard braking? is this not the truth?

 

If you do a search, there have been numerous discussions on this topic.

In general though, my understanding is that the OEM rotors are just fine. There are plenty of people on the forums who track their S with stock rotors. Slotting does help remove gas but i'm not sure if it would be a noticeable upgrade from stock for "street" driving. drilled rotors were applicable back in the day, but now are much more ornamental on street cars. Issues that could come up with rotors: drilled rotors are much more prone to cracking (seen it happen; not good ); slotted rotors are more prone to warping (so i've heard...); OEM has ugly rust

Long story short... if you're going for looks, then feel free to get whatever you want. if you're going for stopping power, a good bang/buck upgrade would be pads IMHO.

 

Everything I have read indicates that it may have been true years ago when pad compounds were very different than they were today. Simply drilling holes in a rotor tends to weaken it (check my picts in the post below), especially if little attention is paid to where the holes are actually lined up.

If the holes are cast into the rotor during production, there may be a ventilation benefit and a small weight savings. Few if any places sell rotors with them (actual cast holes) Even places advertising Brembos are nothing more than drilled or slotted blanks. Since a significant function of the rotor is heat absorption/dissipation, reducing mass can have negative effects too. In any case, in my experience, you can run whatever you want for the most part as long as the car is not subjected to extreme or abnormal braking. What "abnormal" constitutes is the real question. I've had cross-drilled on my 3 series for years with no problems at all but I don't drive it that hard (except when the typical SWFL 80 year old pulls out w/o looking)! My cross-drilled rotors on the S lasted < 100 miles at the track with upgraded pads...

Same basic discussion........

 

Hmmm I found after I started using Ferodo DS2500 pads the OEM rotors lasted less than 8,000kms(3 track days)...They started cracking so becareful...

I might try the 2 piece slotted rotors that SOS sell next