Durability of Slotted/Cross Drilled Rotors

[Be11ydawg]

Now this is not another thread on which is better. I have been doing some reading before deciding on whether to buy slotted and/or crossdrilled rotors and have seen several people comment about having to buy new rotors with their next brake job. Is this to be expected? If a person is buying these rotors primarily for looks and normal street performance versus those that race and autox, do they have unusual wear? I was looking to upgrade only as a part of building a street/show vehicle.

Basically, I would prefer not to buy new rotors with every brake job.

Thanks for the comments.

 

[mikeyb]

I installed drilled and slotted rotors on my Altima last fall and I have not had a problem with them. They actually made a big difference on a midsize sedan thats has crappy oe rotors that wrap easy. The drilled keep the rotor cool so to help prevent wrapping. Slots help the gas that is built up between the pad and rotor escape so not to cause glausing(sp). Plus they look cool. All high performance cars have these.

You should be able to get 2 brake pad changes out of a good set of rotors.

 

[Protege52003]

Installed my cross drilled/slotted rotors last fall and have had no issues with them. my front pads had a little wear when i installed them and they were about 50% worn when i painted the calipers this week (the total miles on the pads are probably 10K).....

i did the rear pads when i put the rotors on and they had a little wear on them. 10-15%......

they squeek a little more than OEM but that could be the pads i use......

I purchased the rotors off a member and they were not used that long.
they are nice........

 

[Revs]

cross-drilled rotors will crack over time, especially if you take the car to the track. I have seen it several times. And honestly, holes do little for cooling, in fact with holes in your rotors there is less material to dispurse heat and less material for the pads to grab onto and the slots do not release gases, they work by cutting the pad so there is better bite.

If your looking for more show then the x-drilled/slotted will be ok, but if your going to be pushing the car at the track i personally would avoid x-drilled, slotted are ok, no issues with cracking that I have seen.

 

[Iceman112k3]

I would reccomend just getting a set of reular rotors which have the center hub area and outside edge powdercoated so you don't get any rust.

Performance+Clean appearance = Win

 

[Protege52003]

If your looking for more show then the x-drilled/slotted will be ok

thats why i use them......they look nice for people who notice them and i think they work great with the hard braking i have tried on them......

 

[98b/w pro]

I warped 2 oem rotors and cracked one. but havent had a problem with me x-drilled and slotted rotors, i didnt notice a signifigant increase in braking either.and i work the hell out of them.
my .02 though

 

[Rio Racer]

I bought drilled and slotted rotors off ebay and i ended up warping them... maybe high quality ones will hold up better. My friend had drilled and slotted rotors and it ended up cracking on him.

 

[98b/w pro]

yeah if there cheaper than oem you should worry about them.

 

[low_psi]

stick with oem, full face rotors. crossdrilled/slotted brake rotors in most cases are a poor choice for anything other than a trailered show car

 

[98b/w pro]

why does brimo use them?

 

[laracroft]

Because Brembo (a reputable company to begin with.. non-ebay) can back them up with a kicka$$ warranty so you wont have to worry about that.

 

[altspace]

There are also the many factors of metal quality. Many of the "knockoffs" are of poor metal quality and thus are prone to damage faster. Many "drilled" rotors are just that, machine drilled which distorts the metal and/or causes fatigue. Wereas the rotors you see on a Porsche or Mercedes are cast molded with the holes.

 

[low_psi]

Yep, they are cast w/ holes in the rotor surface. Holes in the rotors of exotic cars are mainly for weight savings. Our stock front rotors are vented inside for cooling reasons. If you drill through the surface, you're making the cooling less efficient due to removing material and messing up the center vents' pressure.

 

[Cellerator]

According to "Tech Correspondence" From Road and Track

" Currently, Slotted rotors are in favor for perfromance becasue they reduce fade and might help to reduce glazing. Drilled rotors are mainly cosmetic these days, although they are lighter."

well said, I just didn't remember where I read that.

 

[Installshield 2]

They are not more resistant to "warping"...and calling run-out warping is not correct...Run out is when the pedal pulsates while the brakes are applied, and it is caused by poor wheel torquing once the new rotor is on and/or poor pad "bedding"...applying the correct torque to the wheel during rotor installation is insanely important for this...

Just wanted to point out that its not the heat of solid disc rotors causing them to bend...its uneven wear of the friction surface...iron cracks when superheated, it is very difficult to succesfully bend...

Regardless...it is obvious that drilled rotors have less mass than the same volume solid rotor...the holes also create a gas escape during hard braking, which reduces brake fade...

As mentioned before, in racing they had two good functions...One was less mass for the same sized disc...the other was resistant to brake fade...the third is harder to see for the street...less mass gives the rotor less of a heat capacity...the specific heat capacity of the metal is the same, you just have simply less mass...so it takes less kinetic energy to radically increase the temp of the rotor...this is great for racing pads that require a very high temperature for the highest possible kinetic friction coefficient...and this goes the other way also...the rotor will cool faster also, because less mass gives it less of an ability to "hold" the heat...

You can see why that last reason could be bad for the street..it is very true that the heat cycling drilled rotors go through cuts their life down by about a 1/3 relative to a solid vented rotor...they also tend to chew up pads quicker as well...I am firm believer in the pads are the easiest way to get the most out of your stock brakes...We have a number of pad options that will reduce fade, decrease stopping distances, and increase initial bite way better than any rotors would help...

 

[Kansei]

I wonder if my brembo rotors have the holes cast into the mold. I ordered them from brembo so I would think so, but why would they make a separate mold just for drilled rotors for the protege?

my next rotors will be slotted but not drilled, but I've only had these rotors in for about 5k miles so they are doing fine so far.

 

[Installshield 2]

Brembo is one of the largest OE brake manufacturers in the world...and unless it is for their specific performance brake parts, they are usually just plain old OE spec parts...

not to sound confusing...I just mean they do not make performance upgrades for proteges...but they do make oe rotor replacement "blanks" as tire rack refers to them...I am assuming some sub-contracted company did the cross drilling with a press, and that they are not cast with the holes...

where did you buy them?...if you sourced them directly from Brembo, who knows...OE replacement's for compacts that are cross drilled are usually drilled after casting...its far cheaper...the casting with the holes in process is reserved usually for extremely expensive upgrade kits (like Brembo's F50 upgrade)...If you recieved them from some online store or something, I would bet money they are truely brembo rotors that are just "drilled"...

 

[RX]

Hmm, I wonder if the STi comes stock with slotted/drilled rotors.

 

[low_psi]

nope, blanks just like our OEM rotors.