what are the benefits or drilled rotors? im not getting any or in search of rotors or what not... just saw them and was curious whats so special about drilled ones... :confused:

if you don't plan on racing, don't waste your money. The only benefit to a street car is "They look cool".

:)

The theory is that under extreme braking, with all of the friction and heat, the brake pads produce gasses that can lift the pad away from the rotor, increasing braking distance. The point to cross drilling or slotting rotors is to provide somewhere for the gasses to go under extremely hard braking.

The theory is that under extreme braking, with all of the friction and heat, the brake pads produce gasses that can lift the pad away from the rotor, increasing braking distance. The point to cross drilling or slotting rotors is to provide somewhere for the gasses to go under extremely hard braking.


I'd bet 98% of people who mostly drive on the street simply won't brake hard enough or often enough for it to matter.

Another downside to drilled - removing swept area.

I brake hard from 80-100mph nearly every weekday, and I've always been more than happy with the stock brake setup.

Oh, and many drilled rotors start developing cracks around the holes.

The theory is that under extreme braking, with all of the friction and heat, the brake pads produce gasses that can lift the pad away from the rotor, increasing braking distance. The point to cross drilling or slotting rotors is to provide somewhere for the gasses to go under extremely hard braking.
What are the differences between slotting or corss drilling rotors?

http://www.mazda6tech.com/articles/suspension/the-truth-about-brakes.html

cross drilling or slotting the rotors allows, as stated earlier in this thread, for any gasses created by the friction/heat of the brake pads contacting the rotors and slowing the car down to escape, one allowing the pads to make better contact with the rotors, and 2, by allowing the gasses to escape, helping keep the rotors cooler so as to help prevent brake fade. so unless you do hard driving, or just want to look cool, slotted or drilled rotors arent really necessary. also, because the slotting or drilling of the rotors help dissipate the heat generated by the braking process, the rotors are less likely to bend or warp under extreme braking.

i fyou get cross drilled rotors of sloted...with the stock calipers your braking distance will incrase due to (as dmp said) less swept area (i.e. less area for the brake pad to "grad" the rotor..so not as much friction for stoping)

:D

What are the differences between slotting or corss drilling rotors?

Performance-wise, I don't know that there is a difference. I believe drilling came first, and slotting was supposed to be an improvement as far as reducing the cracking.

Also you will "feel" the holes or slots in the brake pedal, takes some getting used to.

lurch,

http://www.mazda6tech.com/articles/...out-brakes.html

Please read the link I posted earlier. Crossdrilled/slotted do not aid in cooling...because air is not more effective then metal at disappating or absorbing heat.

Reducing mass from a rotor = loss of effeciency and MORE heat.

Also the whole "disperses gas" bs is from the early 60's. Current pad technology has completely eliminated that in all but the most extreme situations.

Cross drilled rotors only have two advantages.

In a sports bike, where unsprung weight is el pollo diablo, every ounce counts.
In rally racing/wet racing, the crossdrilled holes help disperse the water and keep a film from forming on the rotor surface.

Other then that they brake less then solid rotors in the dry, have a high likelyhood of cracking, and actually produce hotspots in the rotor surface, which reduces the effectiveness of cooling. For all needs and purposes, cross-drilled rotors are aesthetic rotating cheese graters.

Slotted rotors don't have any of the above disadvantages, and serve mainly to prevent pads from glazing.

Stoptech has a huge number of brake articles if you feel like taking the time to learn more about whats going on with your brake system.

http://www.stoptech.com/technical/

Remember that its tires that primarily determine how fast a car brakes...not the rotors.

What does "the devil chicken" have to do with slotted rotors?

I have Rotora slotted/drilled rotors.
I cannot judge the stopping performance of just the rotor change because I also
switched to EBC redstuff pads and Goodridge lines at the same time.

All I can comment is that I am thrilled with the performance.
The lines alone made a huge change for the better.

And they do look good if nothing else..

http://www.rx8tristateclub.com/photogall/041705_db/View_Photo.asp?photoFile=Thumb_Photos.asp&photoName=/tristatemeet/041705/041705_wa_04.jpg&Cat=All&SortBy=fileName&daysOld=-1&searchText=&Page=1

-B

I have Rotora slotted/drilled rotors.
I cannot judge the stopping performance of just the rotor change because I also
switched to EBC redstuff pads and Goodridge lines at the same time.

All I can comment is that I am thrilled with the performance.
The lines alone made a huge change for the better.

And they do look good if nothing else..

http://www.rx8tristateclub.com/photogall/041705_db/View_Photo.asp?photoFile=Thumb_Photos.asp&photoName=/tristatemeet/041705/041705_wa_04.jpg&Cat=All&SortBy=fileName&daysOld=-1&searchText=&Page=1

-B


I would bet that 99+% of your improvement came from the pad change. :D

lurch,

http://www.mazda6tech.com/articles/...out-brakes.html

Please read the link I posted earlier. Crossdrilled/slotted do not aid in cooling...because air is not more effective then metal at disappating or absorbing heat.

Reducing mass from a rotor = loss of effeciency and MORE heat.

Also the whole "disperses gas" bs is from the early 60's. Current pad technology has completely eliminated that in all but the most extreme situations.

Cross drilled rotors only have two advantages.

In a sports bike, where unsprung weight is el pollo diablo, every ounce counts.
In rally racing/wet racing, the crossdrilled holes help disperse the water and keep a film from forming on the rotor surface.

Other then that they brake less then solid rotors in the dry, have a high likelyhood of cracking, and actually produce hotspots in the rotor surface, which reduces the effectiveness of cooling. For all needs and purposes, cross-drilled rotors are aesthetic rotating cheese graters.

Slotted rotors don't have any of the above disadvantages, and serve mainly to prevent pads from glazing.

Stoptech has a huge number of brake articles if you feel like taking the time to learn more about whats going on with your brake system.

http://www.stoptech.com/technical/

Remember that its tires that primarily determine how fast a car brakes...not the rotors.


I am amazed at how many people still believe the marketing hype rather than the truth (as stated by you - Crossbow)

http://www.mazda6tech.com/articles/...out-brakes.html

this link doesnt work


http://www.stoptech.com/technical/

some interesting stuff there, but question, if slotted/drilled rotors dont provide any real benefit, why are all the upgraded brakes that they sell are slotted, or drilled.

The guy quoted below is a professional brake engineer. Here he is answering a question from me in regards to the benefits of drilled/slotted rotors.

Gomez,
I've done more testing than I care to remember and basically the results from drilled verses slotted are the same each time.

Drilled start off a little better due to some mechanical advantage in the initial bite and slotted finish on top due to slightly more surface area and mass to absorb heat. It's a bit like comparing a 100m sprinter to a 1500m runner.

He said in another thread that drilled rotors perform better in an emergency stopping situation, something that is likely to happen on the street. Drilled street rotors are not for the track. He also said that while drilled/slotted is not required for outgassing, there is a need for better dust evacuation with modern discs/pads.

Do a search on his username for the full story.

Gomez.

i was wondering about the company Endless... has anyone been able to install their pads on their 8 yet? i been wanting to see if anyone has, and if so, please hit me up with some feed back, thnx.

Here's the brake article. For some reason the forum code cut it up.
Brake Article (http://www.mazda6tech.com/articles/suspension/the-truth-about-brakes.html)

The only reason that cross drilled rotors will EVER show a gain over a solid vented rotor...is because 99 times out of a 100, the rotors they are replacing are WORN.

The whole reason the market place tends to sell cross drilled rotors (to those not in the know) are due to economics.

Cross drilled rotors tend to crack and wear abnormally fast compared to solid rotors, due to hot spots caused by the holes...thus they require replacement more often then a vented/solid rotor.

Cross drilled rotors eat pads like a cheese grater. Thus pads need to be replaced more frequently.

More rotors + more pads = more money for the company selling the rotors and the pads.

Pirate, Hymee has Endless pads on his RX-8.

..... if slotted/drilled rotors dont provide any real benefit, why are all the upgraded brakes that they sell are slotted, or drilled.
What grabs atention more, drilled or undrilled rotors? Bling (like sex) sells whether there is a performance benifit or not. :(

If slotted rotors didn't work, then why do the race boys use them?

Like Tri-point and Pettit, even Porterfield says slotted rotors are the way to go.

Drilled rotors work too. crossbow's radical statements aren't believed by all.

As I said earlier, search dbasteve's posts.

Slotted do have some level of benefit as mentioned on the first page of posting. The slots tend to help reduce the chance of glazing in a high stress braking situation.

I've given some links on the falisfied claims of cross-drilled rotors having any advantage. But there are thousands upon thousands more. Just search the internet.

Google is a powerful tool.

Try "brake myths" "cross drilled myths" "cross drilled performance" "cracking rotors"

Try various combinations. Theres far to many links of evidence and testing to link here. If need further evidence, start emailing brake companies. Stoptech, TCE, Powerslot, Willwood, Rota, etc.

Todd from TCE will tell you straight out that cross-drilled is just an aesthetic modification and has no place on the track...and he sells the damn things (and races as well).

Some racers will still use them, mainly for the unsprung weight loss, but will replace them after each race session. This mainly occurs in very lightweight vehicles or bikes.

Visit some race forums for additional info/evidence/reports after the google searches.

http://www.sccaforums.com
http://www.corner-carvers.com

Agreed. I said earlier that drilled street rotors are not for the track. I have cracked drilled rotors myself on the track, so I know.

However, they can actually reduce stopping distances in an emergency situation on the street.