Rotors: ATE power disc vs. cross drilled vs. slotted

[iananderson02]

So, i am about to gather the parts for the fron 325 front brake upgrade and need to decide what type of front rotors to get, my choices:

ATE power discs, or
Brembo or Zimmerman brand cross drilled, or
Something slotted

My concerns (in order of importance): brake fade, pad life, rotor life, looks

So, what are your opinions, which of these choices are best for resistance against fade (does drilling/sloting really make a real world difference), which eats pads fastest, what is the best choice in your opinion.

I have had ATE power discs (on my e32) and they were great, but they don't make rear rotors for our cars so when I need to replace the rears (plan on leaving stock, just upgrading pads/rotors) I will be forced to buy something that doesn't match, not a huge deal but it does look better when front and rear match.

I plan on using Axxis Ultimate pads, I have heard good things...

So, give me your opinions on the rotor issue and any other reccomendations for pads (if you don't reccomend the Axxis Ultimates)...

Thanks
-ian

[1996 328ti]

Brake fade is more dependent on your brake fluid.
I doubt if drilled or slotted are any more resistant to fade than stock rotors.
I'm a fan of genuine BMW rotors. But for looks, I like drilled. As long as the holes are cast.

Ultimates are good, Carbotech Panthers are better but more money.

[iananderson02]

I have always used ATE superblue fluid, alternating with the gold each flush, Seems to be the best bang for the buck. I agree that most fade is probably caused by the fluid, then by pads, then finally the rotors but the idea of having a place for any gasses to escape more easily makes sense. Most if not all race cars run some sort of drilled or slotted rotor for a reason I'd assume.

About the Ultimates, I assume you've had them, what did you think: friction level, dust factor, pad life?

Thanks for the reply...
-ian

[1996 328ti]

Originally Posted by iananderson02

About the Ultimates, I assume you've had them, what did you think: friction level, dust factor, pad life?

I have used Ultimate Axxis. The grab very well for street pads. They do dust a little but clean very easily. Nothing like Jurid or Pagid pads. The Bobcats dust even less. I'm a Carbotech fan and since I swap from Carbotech track pads to street, I like to use a similar compound. But you can't go wrong with Ultimates.

[L84THSKY]

I installed ATE slotted discs with Axxis Ultimate pads this past summer. They stop on a dime, and the brake dust is minimal.

Originally Posted by iananderson02

So, i am about to gather the parts for the fron 325 front brake upgrade and need to decide what type of front rotors to get, my choices:

ATE power discs, or
Brembo or Zimmerman brand cross drilled, or
Something slotted

My concerns (in order of importance): brake fade, pad life, rotor life, looks

So, what are your opinions, which of these choices are best for resistance against fade (does drilling/sloting really make a real world difference), which eats pads fastest, what is the best choice in your opinion.

I have had ATE power discs (on my e32) and they were great, but they don't make rear rotors for our cars so when I need to replace the rears (plan on leaving stock, just upgrading pads/rotors) I will be forced to buy something that doesn't match, not a huge deal but it does look better when front and rear match.

I plan on using Axxis Ultimate pads, I have heard good things...

So, give me your opinions on the rotor issue and any other reccomendations for pads (if you don't reccomend the Axxis Ultimates)...

Thanks
-ian

[DeadpaN]

I just got the ATE powerslot rotors-haven't installed them yet. But at
bfbmw.com I got em for about 118 shipped for a pair of front rotors.

[iananderson02]

How are the Axxis Ultimates cold, is there any warm up needed? Can anyone compare the dust and friction factor to mintex red box pads (thats what i am running right now). Sounds like power discs and Ultimates will be a good setup...
thanks alot
-ian

[1996 328ti]

Originally Posted by iananderson02

How are the Axxis Ultimates cold, is there any warm up needed?

There fine. Nothing to worry about.

[iananderson02]

someone please correct me if i'm wrong but it looks like pbr ultimates are the exact same pads as axxis ultimates (both are formerly known as repco). if this is true bfbmw.com has a GREAT deal on both the Ultimates and the ATE power discs...

[Panzer_M]

NO to ATE

I know a vendor that sells Brembo Sports C/D or slotted for 259 F/R

and these are real Sports not drilled blanks

[Panzer_M]

as for pads I used Hawk and Porterfield

[iananderson02]

Sweet, how bout that link...

Originally Posted by Panzer_M

NO to ATE

I know a vendor that sells Brembo Sports C/D or slotted for 259 F/R

and these are real Sports not drilled blanks

[iananderson02]

Why specifically:

Originally Posted by Panzer_M

NO to ATE

[aceyx]

Neither slotting nor drilling will increase braking performance (aka decrease stopping distance). If you're going for aesthetics, that's fine, just don't get suckered in by the marketing. Both will chew up pads a little faster, but under 20%.

If fade is your biggest concern, go with solid rotors since they have the most material to convert kinetic energy to thermal. Modern carbon-metallic pads don't off-gas nearly as much as the organic type.


While BMW gets their blanks from ATE and Brembo, they also center-balance them again at the factory--the right way, by shaving material. If you get them from a dealer (CCA discount!) they're warrantied for a year.

[J!m]

Originally Posted by aceyx

If fade is your biggest concern, go with solid rotors since they have the most material to convert kinetic energy to thermal. Modern carbon-metallic pads don't off-gas nearly as much as the organic type.

While BMW gets their blanks from ATE and Brembo, they also center-balance them again at the factory--the right way, by shaving material. If you get them from a dealer (CCA discount!) they're warrantied for a year.

By solid I am asuming you mean 'not drilled', and if so, I agree. If you mean without venting, I dissagree for your own reason. The heat produced needs to be dissapated somehow, and the center vanes do this for you. The majority of ti rotors are solid, meaning no venting at all, which is bad, because the heat you produce takes longer to be disapated from the rotor, overheating the wheel bearings and fluid (leading to the soft pedal AKA 'fade') as well as setting up a vapor barier preventing intimate contact of the pad on the rotor preventing maximum efficiency of heat transfer (which drilling and slotting is supposed to solve). BUT all that being said, the ti is a relitively light car, and the chance of getting the front rotors to such a level of heat is slim in a road-going car.

The cross-drilled holes are stress-risers BIG time. Even the cast-in holes (which are substantially beter) allow cracks to propagate, as well as reduce the mass available to transfer the heat (which I think is what aceyx was saying). If anything at all, I would go with ball-milled slots that extend past the pad contact area slightly, and they do not need to be wide, nor should you need more than one slot in contact with the pad area at any time, which means in most cases no more than three equally spaced, narrow (1/8 inch or so), shallow, ball-milled slots (the ball mill produces rounded corners, which reduce stress risers. Square edges are stress risers). Not much in the 'bling' catagory, but that's all that's needed to break the vapor barrier...

And, until I had the M3 motor in my ti, trying to haul that weight down from triple digits on the Meadowbrook Parkway on Long Island, I NEVER experienced brake fade on the road (and, by the way that experience scared the CRAP out of me...).

I also agree with the value of accurate balance, and the BMW rotors are excellent. poor balance will arrive as a weird harmonic at certain speeds that just annoys the crap out of me...