Why cross-drilled rotors are stupid on an 80

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Olathe, KS, USA
I have run powerstop drilled and slotted rotors with medium powerstop pads and currently have 59K miles on the front pads before changing. I just threw in some cheap O'Reillys ceramics and they suck.

The powerstop rotors and pads have been great for me. I bought another set and am waiting.for the weather to break do I can replace all again.

I have a rear caliper hanging up and need to get it fixed.
 
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Jan 11, 2019
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Sacramento
I used to have the same problem in my 99 4Runner, which is one of most common mods is tundra 231mm brake upgrade. I’ve ran powerstop rotors and akebono brake pads. Akebono is as close to OE as aftermarket gets, they are excellent pads. The power stop rotors were drilled /slotted and held up ok, although the zink coating flaked off within couple weeks.

For my 80 which is a much heavier vehicle, I just ordered up some brembo blanks which are excellent quality. I chose to pair that up with brembo pads just so I get the stickers lol. Unfortunately with a lot of aftermarket brakes drums and rotors, if they haven’t been stored properly, they will come out warped out of the box.
 
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Got my DBAs on amazon with heavy duty hawk pads. Very happy customer. Have over 50k without a problem. They are not cheap cross drilled like some others
 

Corbet

Speski OffRoad LTD.
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Durango, Colorado
I'm getting ready to install new brake parts again. Have not posted to this thread since 2014. But I'm still sticking to my DBA T3 and 80 series yellow stuff combo. Nothing I've found has convinced me to change.
 

Bambusiero

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The original posting was 2014, and has now been bumped up to 2019, so we have a significant time span represented in this thread.
It's quite possible that manufactures would tweak their processes and materials over time, so what seems like the same item might actually behave differently now. Just sayin'.

I installed Powerstop crossdrilled & slotted front rotors and pads in late 2018.
They are supposedly carbon fiber / ceramic pads.
The price was good, as a package, so I just shrugged and went with them, in spite of the good advice to avoid crossdrilled and slotted on an offroad vehicle, just due to rocks & dirt catching there & causing gouging.

So far - very positive on the Powerstop.
Good brake performance.
Light pedal pressure easily slows the truck, without any grabbiness. Linear feel.
I do have an assembly quality complaint - the squealers were too long, like half the pad thickness.
Had to grind the tips down, and one just shattered - over hardened steel.
edit: I'll add this clarification.
Whatever brake feel I am noticing has nothing at all to do with cross drilling / slotting.
Those have no benefit, and no effect, one way or the other, under normal duty low temperature conditions.
They can only come into play under high temperature out-gassing induced brake fade.

Or...they come into play by causing rotor failure...later.

Time will tell on the crossdrill cracking.
 
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Bambusiero

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I'm getting ready to install new brake parts again. Have not posted to this thread since 2014. But I'm still sticking to my DBA T3 and 80 series yellow stuff combo. Nothing I've found has convinced me to change.
DBA T3 rotors look like good stuff - "Kangaroo Paws" and all.
Spendy though - $180 each for the rotors :eek: - more than my entire kit.
 

baldilocks

Battle Ground, WA
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This thread went from “why cross drilled rotors are stupid on an 80” to cross drilled rotors are the bees knees. Less mass equals less heat discipation.

Why were cross drilled rotors invented in the first place?
 
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Centennial, CO
Just to get back to the original threads intent:

You would be hard pressed to find a more credible source on the subject we are all facing when deciding if our 80s benefit from drilled rotors....

Truth About "High Performance" Brakes
That's a great article. However, based on my experience, that's the difference between theory and reality. In theory, since I am using crossdrilled rotors, my braking should not be as good, but inreality, my brakes are better than they have ever been with the stock solid rotors. Now maybe it's the rotor material that's better and my crossdrilled pattern is not contributing to that. Regardless, I am enjoying my enhanced braking ability. :)
 
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I have cross drilled rotors, and I can attest that they suck for a completely different reason. Got buried up to the bumper in mud one time (ih8mud) and it took me probably two hours to clean all the crud out of the rotors, which held enough gunk to cause a severe shaking of the whole truck (like WAY out of balance tires).
 
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Jul 21, 2015
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Bend, OR
I drive my 80 like a grandpa so most of the braking is done by the engine.

I have 55k+ miles on my current brake pads (installed by the previous owner in 2012) and they still have plenty of life left. New NAPA semi metallic pads are sitting in boxes on the shelf for when their time comes.

Cross drilled looks cool but my lap times are good enough as is with solid rotors.
 
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Toronto, NSW, Australia
Simple physics tells you that drilled brake rotors are going to fail at the weakest point(s) - where they are drilled. Mechanical stresses there are the greatest and any micro-cracking that starts to occur in the cast metal's crystalline structure will be made worse through the application of heat (via friction with the pads).

I'm no uni scientist, but with braking you get a heat curve in the rotors. But it's not what you might think.

If you measure one specific point on a rotor, the temperature rises along an 'average line' but in a sawtooth fashion where the trailing edge of each 'tooth' is much longer (small amount of cooling as the rotor turns once past the pad contact area), and the rising edge of each 'tooth' is curved sharply upwards (as the target point is in contact with the pads again). Almost exactly like the shape of a tooth on a chainsaw chain.

That, combined with the vibration transferred through the front suspension under braking (remember front brakes do about 90 pct of the work) makes anything that goes out of spec with the metal of the castings turn into failure points. It can manifest as cracking. It can manifest as warping.

The heat energy has to go somewhere, and there are two places it goes - one is into the air but air is a very bad conductor of heat - the other is into all the connected metal parts of the hub/axle assembly. How fast that heat can dissipate is a factor when braking hard and often. Slotted rotors are not too bad with this but drilled rotors have very extreme heat concentration exactly at the outside of each drilled hole (where the rotor metal directly contacts the pad material). Lots of heat not getting away creates big problems for brakes as braking efficiency depends on transfer of energy and you can't get more braking if you can't get rid of the heat fast enough. That's what 'brake fade' is.

Like I said I'm no scientist or engineer but I have enough experience with my vehicles and my work to understand a fair bit about braking systems. To me, drilled rotors just seem like a gimmick. They should be confined to a racing environment only (that's where they came from) where controls over operational parameters are very tight.
 

baldilocks

Battle Ground, WA
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I drive my 80 like a grandpa so most of the braking is done by the engine.

I have 55k+ miles on my current brake pads (installed by the previous owner in 2012) and they still have plenty of life left. New NAPA semi metallic pads are sitting in boxes on the shelf for when their time comes.

Cross drilled looks cool but my lap times are good enough as is with solid rotors.
I’m in the process of revamping my entire brake system to hydro boost (thread to come). I’ve had Advics ceramic pads in the rear two years now and have a new set of Napa Ultra Pemium Ceramic front pads and new front calipers sitting on the work bench now.

More research told me that ceramic pads have no place on my over weight 80 with 37” tires. I looked into those Napa semi metallic and besides being made “elsewhere” they don’t get rave reviews.

I just ordered Hawk Super Duty pads for the front and Stop Tech 309 rears after a lengthy conversation with a helpful guy at BuyBrakes.com.
 
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Corbet

Speski OffRoad LTD.
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Oct 22, 2002
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Durango, Colorado
This thread went from “why cross drilled rotors are stupid on an 80” to cross drilled rotors are the bees knees. Less mass equals less heat discipation.

Why were cross drilled rotors invented in the first place?
For the record I think cross drilled are stupid, I like my slots. Cross drilled fill up with dirt and other debris. I don’t expirence any fade with my DBA/EBC combo. I did with OEM even when I had 33’s or smaller tires. I’m way heavier and in 35’s now. I completely get the more mass thing and science behind solid. It just has not been my real world experience. Maybe it’s the venting design of the DBA’s. Maybe the type of steel? Maybe there is more mass there despite the slots? Don’t really care why they just work better for me.
 
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