how good are the brembo rotors? are they worth it?
what's better, cross drilled or slotted brembo rotors?

 

They're real nice for stopping power, but eat your pads a little quicker than stock, I like um overall.

 

brembo blanks are all you need

 

Just go with autozone blanks.

My friend used them (brembos), and got no better durability on the track than I did with my a-zones.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
They're real nice for stopping power, but eat your pads a little quicker than stock, I like um overall.
</TD></TR></TABLE>

Rotors do not effect brake torque unless you are moving to a larger diameter rotor. I doubt any of us are using carbon rotors, which means they all are cast iron and have the same CF.

 

yep any set of blanks work great. dont waste money on that crossdrilled or slotted ****.

 

brembo are kool, but dont do slotted of crossdrilled in the fronts, the rear's are kool with them...

 

I have brembo slotted and cross drilled in the front with AEM pads for about two years, no problem and I stop like a ****.Stock drums in rear I stop better than my bro's del sol with stock all wheel discs!

 

If you buy brembos check ebay autos they have some really good deals on them. search for "brembo civic"

 

Brembo rotors in general are the best rotors in the world. Slotted are better for street durability, however, cross-drilled are best for racing as they not only dissipate gases better than blanks and refresh the pads better than blanks, but are also lighter weight than even their slotted counterparts and run coolest. The problem is that stress cracks start to form after time and the integrity of the rotor is compromised as time goes on, depending on the compound you choose. Go with slotted for the street, work just as well w/o the pad compound concerns.


Modified by builthatch at 11:32 AM 12/31/2003

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by builthatch &raquo;</TD></TR><TR><TD CLASS="quote">Brembo rotors in general are the best rotors in the world. Slotted are better for street durability, however, cross-drilled are best for racing as they not only dissipate gases better than blanks and refresh the pads better than blanks, but are also lighter weight than even their slotted counterparts and run coolest. The problem is that stress cracks start to form after time and the integrity of the rotor is compromised as time goes on. Go with slotted for the street.</TD></TR></TABLE>

I can't say I necissarily agree. Look at brembo blanks, are the vanes curved? Nope, straight just like stock. However companies like stoptech offer curved vanes

Modern brake pads no longer give off gases, and modern brake pads also have a slot designed into them to allow any gas/vapors someplace to go in the event gases do occur. There is absolutetly no advantage to using drilled rotors on the stock size. The difference in weight is neglagable, the increase in surface area is at a sacrifice of mass (which is critical with the stock sized rotor, what good is slightly better heat radiation if your pads are already faded and your fluid boiled?).

Stick with blanks.

 

Brembo offers staggered vanes, a proprietary design called pillar vane, similar to disc brakes australia's kangaroo paw or whatever they call it. These are proven to be way more effective than any of the continuous vane system, either curved or straight. At this time, I am not sure the percentage of rotors they are offering with this design, but I would venture to guess it is probably 75% of their 3500 drilled and slotted part numbers.

I beg to differ concerning the pad condition when things get hot (heavy braking). There is indeed a ultra thin layer of gasses the pads float on. Though it might not affect performance during regular braking duty, depending on the compound, nonetheless, it's true. Even if this is not true, the slotted/drilled rotors renew the pad contact surface way more effectively than solid surface joints and keep things way cooler than standard rotors, allowing for more time before fade rears its ugly head...

My firm is manufacturer rep firm for brembo usa high performance division, though we've been trained on the various points of their aftermarket (OE replacement) + high performance division.

For everyday driving, stock rotors (which are probably OE brembo rotors anyway) are fine, especially with a higer-performance pad. However, when you start to get into aggressive braking, things change.

 

You are trained to sell your product.

Even if there is a thin layer of gases, quality brake pads are designed to have a slot in them to allow the gases someplace to escape. Why sacrifice mass that results in less thermal storage if you don't have too? Just buy quality brake pads.



Why does the pad surface need to be "renewed" ? Beyond heat, the simple application of pressure to the pad and rotor does not reduce the CF.

 

Keep in mind; this stuff really comes into play when you are racing, autocrossing, canyon carving, running from the police, etc. I do agree that for the majority of enthusiasts, a high performance pad on a superior solid face rotor like honda OE will cut the mustard.

Anyway, to answer your questions: a constantly renewed pad surface eliminates glazing and insures maximum bite of chosen compound. Why do several manufacturers like mercedes, among the 25 diff. manufacturers brembo provides brakes for, decide to use these type of rotors vs. the standard brmebo solid-face rotor on several of their production models?
You are correct about the purpose of the slot in the pad, however, this was to compensate for blank rotors inept dissipating abilities...in high performance driving, the slot, without sacrificing too much pad area, is not as effective as fortifying your setup with said drilled/ slotted rotors.

Also, I forgot to mention, msot of Brembos rotors are high carbon now, which in itself is an advantage independent of surface design.

Brembo can provide you with some pretty neat info about this stuff. email engineers@brembo.com

 

This stuff does not come into play in autocrossing, you are not going to heat up your pads hot enough to need the increase in surface area.

However, with the stock sized rotors, drills are more of a disadvantage than any advantage they could provide. What little vapor that is sometimes created escapes through the slot in the pad, there is no need for drills and the slot is far from inadequate.

The advantage of drilled rotors is the increase in surface area. If done right, it can increase surface area at the sacrifice of mass. If you have plenty of mass, this is not an issue and you can get better cooling at the expense of thermal storage.

While drills and slots can help glazed pads, I have yet to run into anyone running a high quality brake pad at track events that has chronic glazing problems with blank rotors.

I would rather have brakes that can store adequate heat, than reduce the chance of glazing my pads (which I have yet to do).

I am not saying brembo doesn't make a quality product. But the OEM replacement blanks are simply straight vaned cast iron rotors, nothing special.

You can go to any number of companies and get carbon rotors, differential / curved vanes. That is not the point, the point is x-drilled rotors are a thing of the past for a HUGE precent of the population, track oriented or not.

 

When slotting or cross drilling, you are actually removing material from the rotor thus reducing friction and increasing stopping distance. Cross drilled rotors crack pretty quickly on track and slotted rotors are only a little better. Brembo's solid rotors are good.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TBreu007 &raquo;</TD></TR><TR><TD CLASS="quote">When slotting or cross drilling, you are actually removing material from the rotor thus reducing friction and increasing stopping distance. Cross drilled rotors crack pretty quickly on track and slotted rotors are only a little better. Brembo's solid rotors are good.</TD></TR></TABLE>

Actually, CF is independant of area. The increased stopping distance would be due to brake fade caused by inadequate thermal storage.

 

*sigh*

Brembo is not a company that follow fashion over function. They would not offer these drilled/slotted rotors in stock sizes and deem them a performance upgrade if they were subpar or even equal to their solid-faced, stock sized counterparts. Seriously, consider my earlier question, why do many OE higher performance vehicles (like porsche and mercedes, not technical slouches themselves) use cross drilled rotors on many of their high performance, autobahn tested, production vehicles? If this treatment is a thing of the past, why are their cutting edge Gran Turismo crazy brake upgrades cross-drilled?

ABout your comment that Brembo oe replacement are simply str8-vaned, cast iron rotors, nothing special. The OEM replacement blanks are something special compared to the majority or solid-faced OE style replacements. They are balanced and have the tightest run-out tolerances in the world. They also make sure that, unlike most oe replacements, that the symmetry of each braking surface is perfect, which reduces hot-spots (uneven temp) and warping...

To answer the original question, Brembo rotors are good, worth it, and I would personally recommend the slotted vs. the drilled since slotted are not so sensitive to pad compound selection.



Modified by builthatch at 1:39 AM 12/31/2003

 

Brembo, like all profit oriented companies, are in the business of making money. If they could not foreseeable make any money, they either would change what they are doing to become more profitable, or shut down. I can't seriously believe you think that come hell or high water brembo will never sell a product that is unnecessary for braking ability. If the consumer wants drills and slots, they will sell drills and slots.. its that simple.

Why do porsche, Ferrari, etc, use cross drilled rotors? Sales. People like the look of cross drilled rotors. Honestly I like how they look. But I know better than to fall into the hype. Porsche has openly admitted that the only advantage of their cross-drilled rotors is wet braking.

How many people buy a porsche, Ferrari, etc, and actually track it or use the brakes to the extent of having to worry about cooling? I would say very few. Are these cars really specificly designed for the track? No. They are designed for who is buying them. The richer than average folks who want to look cool. While often they can become very track oriented cars, the spring rates/dampening/luxuries/etc is often geared for the street not for a pure track car.

Further, we are talking about stock sized OEM honda rotors. Where there is a lack of adequate mass. You get to larger brakes with plenty of mass, the sacrifice that drilling creates makes less of a difference.

Look at the facts, what do drills in rotors do?

More surface area
Less Mass
An edge for inital bite and to reduce glazing

Surface area radiates heat. So the increase in surface area results in an increase in cooling ability.

Mass is what stores heat, (ie: thermal storage). Once you overheat your rotors, your pads and brake fluid are going to fade and boil.

A race oriented track pad is going to have a very high operating temperature, a slot to deal with any vapors/gas, high CF, and high resistance to glazing (they are no longer organic or Asbestos).

Why would you need drills or slots? There simply is no reason if you have adequate brake components. (there are cases in professional racing ie: rallying, where cleaning the pad surface of dirt is necissary. Or the slight savings in rotational mass is benifical.. but for most of the people on this site they are non-issues).

Your argument that "If brembo or X company does it, it has to be good" is not going to convince me, and I hope no one else. Personally I want to know how/why something works other than taking the word of the company making money off my purchases.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
from stoptech:
For many years most racing rotors were drilled. There were two reasons - the holes gave the "fireband" boundary layer of gasses and particulate matter someplace to go and the edges of the holes gave the pad a better "bite".


Unfortunately the drilled holes also reduced the thermal capacity of the discs and served as very effective "stress raisers" significantly decreasing disc life. Improvements in friction materials have pretty much made the drilled rotor a thing of the past in racing. Most racing rotors currently feature a series of tangential slots or channels that serve the same purpose without the attendant disadvantages.
</TD></TR></TABLE>

As far as the OEM brembo replacements, they may try and go the extra mile. But I have had friends go through them just as fast as autozone rotors, and the only improvement in braking they got with the weight removed from their wallet.

 

i know a guy who had brembo blanks who broke them in perfectly, 2 weeks later went to the track, and groved them. now he just runs autozone rotors. i do the same, no need for any other stock sized rotor. drilling and slotting is like styleteg said all hype. people buy them thinking they will make you brake faster and find out that they in fact do not, then argue with the physics people present to try and justify thier poor desicision to buy a rotor that they thought would makme them stop faster, but only made them spend more money for worsoe proformance and rotor life. Some people buy them becuase they look cool, but the people who really know alot about brakes and have trak only cars use what.....AUTOZONE blanks. now why would somone with alot of money and alot of learning do such a thing? because drilled and slotted offer no true advantage other than looks and the weight reduction of your wallet.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StyleTEG &raquo;</TD></TR><TR><TD CLASS="quote">from stoptech:
For many years most racing rotors were drilled. There were two reasons - the holes gave the "fireband" boundary layer of gasses and particulate matter someplace to go and the edges of the holes gave the pad a better "bite".

Unfortunately the drilled holes also reduced the thermal capacity of the discs and served as very effective "stress raisers" significantly decreasing disc life. Improvements in friction materials have pretty much made the drilled rotor a thing of the past in racing. Most racing rotors currently feature a series of tangential slots or channels that serve the same purpose without the attendant disadvantages."</TD></TR></TABLE>

I could not agree more with their choice for using slotted rotors. I use Brembo slotted, always have, and believe they are a better choice than drilled or solid-face. I have said so many times throughout the thread that I prefer such because they perform just as well for my semi-aggro driving, as drilled rotors, but are not sensitive to certain types of brake pad compounds like drilled, something with which stop-tech obviously concurs.

HOWEVER,


The design of the holes, the frequency, placement, the chamfer angle, etc. on brembo rotors and most high-performance drilled rotors has made the "stress-raisers" point relatively moot (exemplified by OEM using them on productoin vehicles that many times adhere to "normal" service intervals like mercedes, porsche, etc), though they are more sensitive to pad compound selection than most. Mercedes and Porsche put these on their rides with no expectation of faster service intervals. Do you think the S500, a powerful, heavy production car, has a problem with faster wear, or the Porsche 996 TT or even the hair-dresser car Carrera have issue with accelerated rotor wear? No.

I am sorry to here that there is so much negativity towards these parts and brembos motivations as a brake manufacturer in Ann Arbor, with 2 guys from the same area knocking the stuff, but, the fact is, worldwide, there is a reason brembo is number 1...bottom line is, if the stuff did not werk, brembo would not do it, but more importantly, people would not buy it and use it on their street cars, race cars, etc, including vehicle OEM.

 

brembo. you guys are bashing brembo but i personally don't see how you can judge a product on a few situations. how many lemons has honda ever sold to the public? we still stand behind them. not to say brembo sends out lemons, but i'm sure everynow and then, as with any company, their are problems. all i know is i have run brembo slotted for 3 years, i'm on my 2nd set of pads. i use axis metal something or other. i'm hard on my braking and definatly can tell a difference with these rotors. i'd say that rotors made a difference just as signifigant as my goodrich ss braided brake lines.....
-Erik &lt;--- runs slotted/drilled brembo's @ the track

 

You guys misunderstand what I am saying so much.

Again, I am not bashing brembo. They make quality brake products. I agree, there is a reason why many race teams use their products.

Regardless, brembo is in the business of making money. If you think otherwise you are fooling yourself.

Production cars and rotor wear really are not a valid argument. On the street, you are not going to heat up your brakes to the point of these drills/slots becoming a stress point. Like I stated earlier these cars are designed to be street cars, because the consumers are street drivers, not track drivers.

If you can give me valid reasons as to why drills and slots are beneficial on a stock sized honda rotor, I will completely admit I was wrong and agree with you.

So far the reasons you have said are a band-aids for poor pad choice, and ignoring thermal storage. The only other reason you have said is "because brembo said so".

Porsche air cooled their engines for a long time. If they had never switched, would that mean we should all use nothing but air cooling?

Again, I am not knocking brembo. They are a good company. I am knocking running drill rotors, as their benefits are really just a thing of the past.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StyleTEG &raquo;</TD></TR><TR><TD CLASS="quote">
Regardless, brembo is in the business of making money. If you think otherwise you are fooling yourself.
</TD></TR></TABLE>

No, Brembo is in the brake business, not the money business. Indeed they make money by selling brakes but you don't want to commit the fallacy of false cause now do you?

The following statement is logically fallacious:
Brembo makes brakes
Brembo sells brakes for money
Therefore Brembo is in the business of making money.

Note to everyone else. None of that matters when it comes to stopping your car.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StyleTEG &raquo;</TD></TR><TR><TD CLASS="quote">
If you can give me valid reasons as to why drills and slots are beneficial on a stock sized honda rotor, I will completely admit I was wrong and agree with you.
</TD></TR></TABLE>

Wet braking. My solid rotors were dangerous when using Comptech MM pads when it was raining. I switched to Powerslot rotors and the problem was solved. That doens't apply to everyone, just me though.

One other thing that was mentioned at least twice, drillling rotors *reduces* surface area, not increases it.

Cheers,
Roy

 

So they make brakes as a Hobie? If that were the case, why not sell everything at cost, who needs to turn a profit if they are not out to make money?

Properly drilling rotors increases surface area. This is very basic geometry here.

The surface area of a cylinder is

Surface area = 2*pi*r*h

How ever you are removing the front/rear face of the cylinder by drilling so you subtract

2*pi*r^2 (surface area of a circle).

So for example:

Take a rotor that is 8mm thick, and drill a 12mm (diameter) hole in it

The area that is removed is 2 * 3.14 * 6(6) = 226.08mm

The area that is gained is 2 * 3.14 * 6 * 8 = 301.44mm

The difference?

301.44 - 226.08 = 75.36mm.

Hey look, you gained surface area.

Wet braking was mentioned. However, do you really think its worth the reduction in mass/thermal storage all the time for the occational time you may need to wet brake? If you are in a situation where you have to worry about performance wet braking, then just have a backup set of drilled rotors for that perticular competition day. Don't sacrifice your braking all the time, thats just rediculess.

 

don't sweat it StyleTEG; you've given your opinion and some of us have conveyed converse feelings. The original postee can read what we all think and decide to answer his original question.