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Jan. 9, 2009 10:12 p.m. gamby UberDork

OK--I know the conventional wisdom, but I'd like it confirmed once and for all.

My car needs brakes. While normally I'm a 'function over fashion' guy in the GRM vein, I wouldn't mind some semi-bling cross-drilled rotors for my 99 Civic Si. They'd be OEM replacements w' 15" wheels, so they'll still look decent at stock size.

I've checked out the Brembo units and Powerstop units. The ebay ones scare me.

Are these trackable/auto-xable in your personal experience???

Is this further manifestation of my Peter Pan complex???

I'll provide this for cut and paste purposes:

Just get Brembo blanks
Jan. 9, 2009 10:29 p.m. ArtOfRuin Reader

Or get slotted discs. Not as blingy as cross-drilled, but blingier than blanks and less prone to cracking than cross-drilled. From what I've heard, any braking benefit is negligable with slotted/cross-drilled/both.
Jan. 9, 2009 10:58 p.m. Keith UltraDork

There's a theoretical advantage to slots and holes, as they wipe the incandescent layer off the face of the pad. So sez Carroll Smith, anyhow. I've seen drilled Powerstops crack on the track, never seen any problems with slotted. I don't imagine autox would be hard on rotors though.
Jan. 9, 2009 11:24 p.m. P71 HalfDork

I HPDE'd the 2-ton plus P71 on eBay drilled/slotted rotors and even managed to overheat the rear brakes doing powerbrake burnouts drag racing. Still no cracks. I think you just have to make sure the drills are chamfered and it's ok.
Jan. 9, 2009 11:30 p.m. noisycricket Reader

If you're not making the rotors incandescent, you're good to go. If you ARE making them glow... first, that's pretty badass. But removing metal actually makes the brakes run hotter since they have less mass to absorb the BTUs, so crossdrilling sucks.

I do run slotted pads.
Jan. 10, 2009 5:49 a.m. Grtechguy SuperDork

slotted pads? I haven't seen that
Jan. 10, 2009 6:08 a.m. ignorant PowerDork

Carroll Smith goes with slotted to help clean the surface of the pad.. If I remember from "Engineer to Win" It was to help stop fade/glazing...
Jan. 10, 2009 6:51 a.m. ddavidv SuperDork

The ultimate cross-drilled rotors thread. Not for those offended by R-rated language: Corner Carvers flames cross drilled rotors After reading the thread and many of the references cited within, and observing rotor cracking at the track, I am of the strong impression for anything other than street poseur use they are a bad idea and a terribly poor expenditure. Slotted, OK. I run simple, solid, inexpensive Brembo rotors on my track cars and even they will crack after a lot of hard, abusive use. Proper pads and better ducting will do far more than any weakend, overpriced Fast-n-Furious drilled rotor.
Jan. 10, 2009 8:09 a.m. stan_d Dork

I suffered from brake fade on my 86 SAAB 900 in autocross runs untill i cross drilled a set of brembo blanks . in 5 yrs they never cracked . I also drilled a set of cheep rotors for my jeep and they never cracked .they both stopped better in the rain . I only drilled 3/16 " holes and chamferd them down to min thickness.

Stan
Jan. 10, 2009 8:11 a.m. njansenv New Reader

"I'd love to hear NissanLunatic explain how removing mass from a heat sink will make it dissapate heat more quickly..."

You know, I laughed out loud when I read that. Take a block of aluminum, use it as a heat sink. Now machine that same block of aluminum and cut it such that you end up with fins/pins/whatever you can to increase the surface area. Now sit back and watch temperature drop faster with your drastically more efficient heat sink.

Thermal mass only slows the rate of temperature change. (both up and down) This could result in lower peak temperatures, but ultimately what matters is getting the energy from the rotor to the air.

That said, there are other factors at play, and I won't run crossdrilled rotors for the reasons mentioned above.
Jan. 10, 2009 8:32 a.m. Will Reader

I'm not a fan of drilled rotors, but I know that some autocross guys--including some really, really good ones--like drilled rotors for that last little bit of weight savings, especially on something like a Miata. IIRC, in one of Hollis' articles in GRM he said that cross drilling plus shaving the rotor to min. thickness dropped 3 pounds per rotor. On a light autocross car that doesn't need much braking I think drilled rotors would make sense, but not on my big old cars.
Jan. 10, 2009 9:19 a.m. Wally UltraDork

Will wrote:

I'm not a fan of drilled rotors, but I know that some autocross guys--including some really, really good ones--like drilled rotors for that last little bit of weight savings, especially on something like a Miata. IIRC, in one of Hollis' articles in GRM he said that cross drilling plus shaving the rotor to min. thickness dropped 3 pounds per rotor. On a light autocross car that doesn't need much braking I think drilled rotors would make sense, but not on my big old cars.

If the car is light enough the rotors don't even have to be round
Jan. 10, 2009 9:28 a.m. iceracer Reader

Brake fade at an auto x ! Wow. Go to any road race track and see what they are running.
Jan. 10, 2009 9:44 a.m. AngryCorvair Dork

stan_d wrote:

I suffered from brake fade on my 86 SAAB 900 in autocross runs untill i cross drilled a set of brembo blanks . in 5 yrs they never cracked . I also drilled a set of cheep rotors for my jeep and they never cracked .they both stopped better in the rain . I only drilled 3/16 " holes and chamferd them down to min thickness.

Stan

any chance you flushed crappy old fluid and replaced with fresh at the same time that you installed the miracle rotors?
Jan. 10, 2009 9:50 a.m. AngryCorvair Dork

Will wrote:

I'm not a fan of drilled rotors, but I know that some autocross guys--including some really, really good ones--like drilled rotors for that last little bit of weight savings, especially on something like a Miata. IIRC, in one of Hollis' articles in GRM he said that cross drilling plus shaving the rotor to min. thickness dropped 3 pounds per rotor. On a light autocross car that doesn't need much braking I think drilled rotors would make sense, but not on my big old cars.

June 2008 GRM, "Think Globally, Stop Locally: A Systems Approach to Brake Component Upgrades" is quite possibly the best. brake. article. ever.

in short, if you never ever overheat your current brakes in the most abusive use you dish out, then yes perhaps you could afford to lose a little of the thermal mass by drilling and shaving to min thickness. Holes should be chamfered to reduce stress concentration.

to another post in this thread:

slotted pads are for noise abatement, not performance.
Jan. 10, 2009 9:57 a.m. Keith UltraDork

Yes, definitely distinguish between slotted pads and slotted rotors.

James Walker Jr, the guy who's written a number of brake articles for GRM and for the Stoptech site, has a book out called High Performance Brake Systems. It's a very high-quality read, definitely worth the money. I suspect he's the one that wrote that June '08 article, I don't have the issue handy to check.
Jan. 10, 2009 9:57 a.m. Wally UltraDork

June 2008 GRM, "Think Globally, Stop Locally: A Systems Approach to Brake Component Upgrades" is quite possibly the best. brake. article. ever.

That article changed my life
Jan. 10, 2009 10:36 a.m. joey48442 Dork

AngryCorvair wrote:

Will wrote:

I'm not a fan of drilled rotors, but I know that some autocross guys--including some really, really good ones--like drilled rotors for that last little bit of weight savings, especially on something like a Miata. IIRC, in one of Hollis' articles in GRM he said that cross drilling plus shaving the rotor to min. thickness dropped 3 pounds per rotor. On a light autocross car that doesn't need much braking I think drilled rotors would make sense, but not on my big old cars.

June 2008 GRM, "Think Globally, Stop Locally: A Systems Approach to Brake Component Upgrades" is quite possibly the best. brake. article. ever.

I think I know the guy who wrote that...

Joey

in short, if you never ever overheat your current brakes in the most abusive use you dish out, then yes perhaps you could afford to lose a little of the thermal mass by drilling and shaving to min thickness. Holes should be chamfered to reduce stress concentration.

to another post in this thread:

slotted pads are for noise abatement, not performance.
Jan. 10, 2009 12:53 p.m. sachilles Reader

I'm not a big fan. My wrx came with a set from a reputable vendor. I broke one at a track event and posted the vid here. In the ensuing aftermath, the vendor said they shouldn't be used for track events or performance driving. Which I thought was odd considering the vendor quality reputation. I didn't want them to replace the rotors or anything. However, I thought there might have been some sort of fatigue issue or something. I offered them back to the company so they could investigate the failure and improve their product. The sent me a packing label, and I sent them back. I emailed them a month later, just to see if they found anything about the failure, and they didn't respond. Didn't get a warm and fuzzy feeling about it.

Long story short, I don't think they are a great idea.
Jan. 10, 2009 1:16 p.m. Chris_V SuperDork

So, crossdrilling is supposedly done to make the brakes work better. BUT, they only work if you don't need to use much braking already, where you aren't NEEDING better braking. And under hard use, where you NEED and are USING better braking, they are a bad idea.

Hmm. So, if they are only ok under light duty use, then what are they doing for you, anyhow?

They lighten things, alright. Primarily wallets.
Jan. 10, 2009 1:27 p.m. gamby UberDork

OK. Went though a big of the corner-carvers thread (as well as this one) and the drilled ones are out.

These look nice (and reasonable) (and abuse-able).

http://www.tirerack.com/brakes/brakes.jsp?&make=ATE&model=PremiumOne+Slott...

ATE is a more reputable name than the ebay Z0MGsp33d-brand units, IMHO. Reasonable price, too.

Very subjective, inflammatory subject, brakes are.
Jan. 10, 2009 1:58 p.m. sachilles Reader

In my case, I don't think the cross drilling was the root problem. It seemed obvious to me that the rotors broke in the tophat area.
Jan. 10, 2009 2:41 p.m. AngryCorvair Dork

sachilles wrote:

In my case, I don't think the cross drilling was the root problem. It seemed obvious to me that the rotors broke in the tophat area.

good thing you sent the lawsuit back to them.
Jan. 10, 2009 2:43 p.m. AngryCorvair Dork

Keith wrote:

James Walker Jr, the guy who's written a number of brake articles for GRM and for the Stoptech site, has a book out called High Performance Brake Systems. It's a very high-quality read, definitely worth the money. I suspect he's the one that wrote that June '08 article, I don't have the issue handy to check.

Nooooo! That article was written by your favorite angry corvair person, AngryCorvair! James is a good friend and former coworker of mine in the brake industry, and he's the lead instructor of the SAE courses for which I am an in-car instructor. You are correct that his book is an excellent resource.
Jan. 10, 2009 3:08 p.m. sachilles Reader

AngryCorvair wrote:

sachilles wrote:

In my case, I don't think the cross drilling was the root problem. It seemed obvious to me that the rotors broke in the tophat area.

good thing you sent the lawsuit back to them.

You are most likely correct. I just thought it was a poor customer service tact on their part. I won't bash their name here. However, nobody that was at that event, nor anyone from my club will buy parts from them any longer. Probably in this day and age of litigation.....it could be a rough world in the brake industry.

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