What do you think about these rotors?

[valex9499]

Well the time has come to buy new rotors. I found these on ecs, I never heard about them so I wanted to hear your input on them.

Thanks

BMW E53 X5 M54 3.0L > Braking > Rotors > ES#2193128 Front Cross Drilled And Slotted Brake Rotors - Pair (332x30) - 6765457XSGMTLRA

[JCL]

Drilled and slotted, so mainly about the looks and not the performance, IMO.

I'd go with OE. ECS sell them as well, they will give you the best performance and the price isn't out of line.

[valex9499]

Originally Posted by JCL

Drilled and slotted, so mainly about the looks and not the performance, IMO.

I'd go with OE. ECS sell them as well, they will give you the best performance and the price isn't out of line.

ok, thanks. Ill probably get the OE rotors. Would the drilled and slotted run cooler though? Or maybe just the drilled?

[motordavid]

Originally Posted by valex9499

ok, thanks. Ill probably get the OE rotors. Would the drilled and slotted run cooler though? Or maybe just the drilled?

'Cooler'? I can't think of a normal driving situ you will encounter in flat FL, that would require any slight potential that slotted and/or drilled brake rotors would provide...if you like the looks of the non-std rotors, it is your choice, but 'performance' gains are minimal to none, in real world driving, imo.

I may get slots next time, for the X or the Vette, but I will get black hatted rotors for sure. It is aesthetics, not 'performance' in normal street use.
GL, mD

[Quicksilver]

This might help. http://www.xoutpost.com/bmw-sav-foru...e53-4-8is.html

[pnoyako85]

i would get the drilled and slotted due to its CLEANER braking residue...no brake dust when you have silver wheels it keeps it clean when you have the drilled and slotted rotors....not like the plain OE rotors that give that black residue on silver after one day of driving and you have to clean your wheels again..IMHO....

[JCL]

Originally Posted by valex9499

ok, thanks. Ill probably get the OE rotors. Would the drilled and slotted run cooler though? Or maybe just the drilled?

No, they don't run any cooler.

Drilled rotors were originally designed for pads that outgassed. The holes let the gases escape. No modern street pads outgas, though. A drilled rotor is structurally weaker, and therefore more likely to crack. If the rotor blank is designed to be drilled when it is designed and manufactured (ie Porsche OE) then fine, but a standard rotor that has been drilled for looks is prone to cracking.

Cooling is primarily a function of the cooling fins between the two rotor surfaces. Cheap rotors have poor cooling, OE rotors generally have the best. People can't see the cooling fins, so don't realize the importance of them.

Slotted rotors can be noisier due to the action of the slots on the brake pad, resulting in shorter pad life.

[JCL]

Originally Posted by pnoyako85

i would get the drilled and slotted due to its CLEANER braking residue...no brake dust when you have silver wheels it keeps it clean when you have the drilled and slotted rotors....not like the plain OE rotors that give that black residue on silver after one day of driving and you have to clean your wheels again..IMHO....

That is a function of the pad composition more than the rotor. Slotted rotors would produce more dust since they tend to be harder on pads.

[pnoyako85]

Originally Posted by JCL

That is a function of the pad composition more than the rotor. Slotted rotors would produce more dust since they tend to be harder on pads.

but how come when i put those slotted and drilled rotors the dust went away..or just say..it did not stay on my rims .....i put OE pads .......and when i put it on my other car silver wheels..it always was clean and dust free for weeks when it did not rain....

[JCL]

Originally Posted by pnoyako85

but how come when i put those slotted and drilled rotors the dust went away..or just say..it did not stay on my rims .....i put OE pads .......and when i put it on my other car silver wheels..it always was clean and dust free for weeks when it did not rain....

I have no idea. But when I have used alternate pad compositions I have managed to eliminate over 90% of the dust as well.

What reason is there for drilled rotors to produce less dust from the same pad? There are a series of edges that cut across the pad surface, sometimes setting up noise. Those edges, if not properly chamfered, can wear pads faster. What mechanism would cause the quantity of dust to change, for the exact same pad? My suspicion is that it isn't the exact same pad.