masterstone

So I originally started snooping around here when I got my TL because I noticed right away the brakes are hurting. I do know that the dealer (non-acura) put "New pads/rotors" on, and being around the block everyone knows what that means. What I've come across while on here in regards to brake kits, pads, rotors, bbk, etc is everyone seems to point out excelerate [stoptech] right away. I am in a position where I don't feel comfortable spending ~$460 on rotors and pads. With that in mind I started reading up on stoptech's website, as well as others. I have found the reasoning behind slotted, drilled, and x-drilled. At the same time as the 'benefits' of these high priced rotors, I noticed one red flag - longevity. Some people say "F**k those I just buy new cheap rotors every x months/years". Also and I believe to be another red flag is the myths behind drilled, as well as the cracking/etc that come with them. I've come to the conclusion I am willing to put out for some Slotted and ceramic pads (of course with the groove in the middle). Either that or I can go cheap and get the "recommended OEM replacement part"

What are my options like if I did not want to shell for Stoptech, Brembo, etc on rotors? Kit-wise I have seen a few from companies like Powerstop for ~$300 but then as with all things interweb related there are the "OMG BEST BRAKES EVER LOLZ" types and the "These brakes are garbage, etc etc" Where are the people who want to actually help?

justnspace

iTrader: (1)

first; any combination of rotors and pads will stop your car.
yes, even the cheap ones from autozone.

2nd; if you really think about it; drilling holes into a flat surface kinda does make the material weaker or prone to cracks.
have you ever tried to drill two holes in close proximity to each other? yes, hard task.

3rd; there is a vendor on here called brake motive. can get all 4 corners(rotors and pads) for about 250 or somehting cheap like that!

4th; tires play a bigger role in stopping the car than brakes do.

zachlone

I just bought a set off ebay (drill and slotted) all 4 rotors and pads for $160. They work good so far, little noisy but i also found out that i have a stuck caliper piston that needs replaced.

Excelerate

iTrader: (1)

You get what you pay for.

The STOPTECH components are more durable, better quality, and are composed of "power alloys". As with anything you can choose a cheaper product and it can work. But there is a difference and you're paying for the advancements STOPTECH has put in place.

http://www.stoptech.com/products/rot...h-sport-rotors


E-Coated Finish

Every StopTech® Sport Rotor is finished with black e-coating on both sides of the hat, inside the the cooling vanes, and on the outside edge. E-coating is a superior electro-statically applied finish designed to withstand 400 hours of salt water exposure without rusting. This is especially important on both mounting faces of the hat where it touches the hub flange and back face of the wheel. Any accumulation of rust in these area can lead to installed lateral run out issues.

Power Alloy Metallurgy

Power Alloy metallurgy is an exclusive feature of many StopTech® rotors. In specific vehicle applications, StopTech works with foundry partners to increase the molybdenum or carbon content of the castings, and to carefully control the cooling rate during production to reach targets for hardness and tensile strength.
Cooling Vane Design

Nearly all StopTech® 1-piece rotors have unique slot or hole patterns for the left and right sides of the vehicle. For these directional patterns, straight vane or pillar vane rotors are used to ensure that a drilled hole never touches a cooling vane.

bouncer07

Brake Motive like Justn pointed out if you want cheap route. You'll get what you pay for. I tried these out and seems to have a good bite, less brake dust. Depending on your application, " I'm brembo'd bro ".

masterstone

True enough. That being said my application is sometimes daily driving, city to highway to city. I notice these rotors are a piece when I'm not in SS mode and braking coming off the highway. I actually need to downshift (using the engine to assist braking) otherwise I get a brutal grind, as well as squeal. I understand you get what you pay for, and yes tires help more than most think. I just don't want to shell out ~500 for some wicked rotors only to need them replaced in a couple years. I get the idea of drilling causing cracks, but I also read drilling is to allow the rotors to cool down quicker. Knowing this, and the fact heating up and cooling down too quickly is a bad thing, I don't think I'll go to the extreme in that sense.

All things aside, since powerstop's k2298 seems legit enough at around $300, but doesn't provide just a slotted rotor, and brake motive not having their own website (rather not go that cheap) what are some other good options?

XLR8 do you guys have anyone to recommend otherwise? Also if need be can ship to Canaduh? Side note: I absolutely HATE the word/term cheap. Instantly makes me think of the 20 per rotor jap brand.

justnspace

iTrader: (1)

in theory; slotted and drilled rotors help cool down the rotor to prevent brake fade.
brake fade is when temperatures reach so high that your brakes fade.
Under normal driving; a driver will NEVER reach brake fade.
unless repeated stops happen, like for example driving on a track with multiple twist and turns.

I feel that its your pads that are squeaking and giving you problems.
YOU MIGHT NOT EVEN HAVE to replace your rotors if they are still in spec.

different pads provide different levels of bite.
also, different pad materials will leave what we call "brake Dust"

I went with a ceramic pad because not even a 30 min drive caused MASSIVE brake dust and made my freshly washed car look dirty.

94eg!

FYI: I just purchased Stoptech compound pads & Centric High-Carbon rotors for $172 shipped on AmazingSavingsAutoParts.com. The order made it to Las Vegas in 1.5 days exactly from the instant I paid with paypal. And this is for my Brembo equipped car (more expensive rotors & pads).

For those that don't know, Centric is the makers of Stoptech, and their High-Carbon (previously called Power-Alloy) is the same exact rotor used to make the extremely expensive Stop-tech, Power Slot & Sport Stop rotors. Save yourself some money and buy the super high quality blank rotors.

Brembo equipped fronts:
Stoptech pads: 309.10010
High Carbon rotors: 125.40062

Non-Brembo equipped fronts:
Stoptech pads: 309.07870
High Carbon rotor (curved vane right side): 125.40046.0
High Carbon rotor (curved vane left side): 125.40046.1

Rears:
Stoptech pads: 309.05360
High Carbon Rotors: 125.40061

94eg!

Oh and yes, as Justin said you can do a simple pad slap. So long as your rotors are still thick enough and not causing vibration. All you need to do is a hard-bed-in of the pads after swapping then in. Just be sure to service your caliper slide pins while you're in there. Use one of those little packets of syl-glide at the parts counter to re-lube the pins. Unless you brembos. In that case there are no pins.

masterstone

Appreciate the second response spaceman, and thanks 94. My realistic option was to get some ceramic pads first and see if that solves the problem. I am prone to doing the "try this first" before shelling out for a big kit. If I get the ceramic pads and they don't fix the issue, then I can upgrade to the rotors as well while not losing money as I'd need the pads anyways. Being Dr. Obvious on that I do just like to hear myself talk. Also 94eg, you live in vegas? How in the world are you not drunk, gambling or both? lol

thanks guys, I'll take my route and if need be go for centric. Crap I just noticed you posted some specs, even more thanks on that.

Undying Dreams

iTrader: (3)

I love my Brakemotive kit

94eg!

Who says I'm not? >.>

NvrDwn

Don't buy slotted or drilled rotors. They are inferior to everything else. They are more about looking badass than being badass. More or less the slots were created to remove gass from between the rotor and pad (which with todays tech doesn't happen) and the drilled were meant to cool the rotor. (metal conducts heat better than air therefore the more metal the better the heat is distributed (holes = less metal = less cooling))

I read a well written page or two or this type of thing and can't seem to find it.

However I did find this: http://honda-tech.com/showthread.php?t=1437513

Btw no one will find an F1 car with drilled and or slotted rotors, they are all plain.

94eg!

Actually slots serve to keep the pads clean, but that is all. Holes create stress risers AND lower rotor mass. Both are bad.

Modern slot technology isn't even slots any more. The old straight slots are pretty obsolete.



Truth be told, anything less than carbon rotors these days is considered armature. So why bother at all. Get blank rotors and get the job done while keeping your wallet fatter.

masterstone

Exactly. Also NVR:

" At the same time as the 'benefits' of these high priced rotors, I noticed one red flag - longevity"

I read this same article I believe, it was a black backgrounded page with the guys' opinion on rotors. Basically slotted is the way to go - before the brake pad makers began slotted the pads themselves.

94 - your typing is too good for you to be truly drunk. Side note: Old vegas casino (that old western style one with the tv show) has a wicked spanish guy who sells footballs of beer or high balls. awesome.

NvrDwn

Really the only benefit slotted rotors have over plain is keeping water off the rotor.

If anyone wants there brakes to perform well get a good plain rotor, ceramic pads, ss brake lines, and good break fluid.

Also a bbk is good so you have more metal to spread out the heat.

94eg!

BBK is a whole new can of worms. This is where you get into brake bias problems.


PS: "Ceramic" in and of itself doesn't really mean very much. You could have really good ceramic pads, and you can have really crappy ones. Personally I like the Centric way of doing things. They offer lots of compounds and give you nice charts to help you pick the compound that's right for you. These guys are really good. Their Stoptech brand is really tops too. Here is the chart to compare.

FYI: The 100-series low metallic compound is exactly the same as what we get with our OEM Brembo pads found on the TL-S/sport, CTS-V & Volvo S60-R.

AcuraIntegTL

OP, I was hesitant to purchase the brakemotive kit too, but I needed a replacement that fit my budget at the time. My plan was to switch it out to the Stoptech package once I had the funds to do so, however, I have to say that the brakemotive kit is working perfectly. I’ve only put 1K miles on these rotors and pads, and so far so good.

masterstone

See there are two things I notice right away, and this is exactly why I posted what i did in the OP.

NVR says " More or less the slots were created to remove gass from between the rotor and pad (which with todays tech doesn't happen) and the drilled were meant to cool the rotor."

Few posts later "Really the only benefit slotted rotors have over plain is keeping water off the rotor."

I don't mean to bash or get personal but this is exactly what I've found all over the net and am trying to avoid.

I also don't want to seem like I'm riding his you know what, but the photo is fact, and what I'm looking into. By the above shown I'd prefer to go with the 100 series semi metallic as it seems to be the most well rounded pad. Now to remove my crap rotors and replace with some solid OE brembo's should do the trick.

I hate cars

It would be nice to keep this to truthful facts or educated opinions.

Formula One first... You will never find a slotted carbon/carbon brake system. It's utterly unnecessary (think about why steel rotors are slotted and what material our brake pads are made of) and it can have serious negative effects on the structural integrity of that material. Most drag race methanol and even top fuel cars don't have water jackets thus they have no coolant or radiators but I don't think that would work well on our TLs. Some racing technologies don't apply here, a carbon/carbon brake system would be scary on the street, lots of wrecks.

Slotted rotors are not inferior to blanks. Depending on the pad and intended usage they can be useful. There is no issue with wear or longevity with slotted rotors. Brake pad wear does not increase with drilled and/or slotted rotors until the pad is very hot. The primary purpose is to clean the pad surface to prevent glazing and also for outgassing which we don't have to worry about too much any more but there are some pads that gas. In my experience slotted rotors are as quiet as blanks.

Drilled rotors are a different story. They *can* offer better cooling but only where there is constant airflow through the rotor such as high speeds and air cooling ducts. On the street even with spirited driving we will never see any additional cooling from drilled rotors. All drilled rotors will crack at the holes given enough time, no exceptions. The only plus on a street car is if the rotor is getting wet, they will continue to work nearly the same. It's an easy choice, no performance advantage except in the rain but huge disadvantages.

Drilling for weight reduction on a street car is trading brake reliability for a performance increase you will never notice in both rotating, static, and unsprung weight.

Rotors cool in 3 ways, 4 ways sort of. Conductive, convective, radiation. The ratio will change depending on whether you have 1pc or 2pc rotors and as the temperature rises the ratios will change. A heavy rotor will act as a heatsink which is fine to knock down the spikes but using mass has many downsides. Just like as I've gone through many different intercoolers on my turbo car and watched the charge air temps change from intercooler to intercooler but more importantly how much heat they're able to absorb when sitting at the line under 20psi with the car not moving, no airflow. You see a slow increase in temperature rise when standing still on some of the larger and heavier intercoolers but they don't like to drop temperature as quickly either as you get airflow, even into the triple digits. Same with a rotor, I look at weight as a one time use sort of thing, not bad when there's not enough airflow to get good convective cooling but they're also not going to cool off as quickly once the car is moving faster and has good airflow. The difference with brakes is you're not making heat when you're standing still.

Brakes have no impact on a single stop stopping distance as long as bias is unchanged. You can have 15" rotors and the car will not stop any quicker in a single stop than a 10" rotor assuming both have the power to lock the wheels which they will. Changing the tires can have a dramatic impact on stopping distances. Brakes can't increase the friction between the tires and the road.

Larger brakes, better pads, and better fluid reduce the chance of brake fade during repeated hard stops. A larger rotor will shed heat quicker. A better pad will continue to work at a higher temperature (but will likely dust more and/or be noisier). A better caliper will be a better barrier between the heat in the rotor and pads and the brake fluid, they will apply even pressure across the pads and they will be rigid, increasing pedal feel and deflection. Better brake fluid will resist boiling and IMO a truly good street fluid will have a high "wet" boiling point. In the real world it's not going to be perfectly dry. I think the wet boiling point is more representative of real world conditions, especially after it's been in the car for a year or two.

That brings up the types of brake fade... Pads fade when they get too hot to maintain a good friction coefficient against the rotor. There's usually warning signs, they rarely fade all at once. Fluid is usually all or nothing. Once it boils you completely lose the brakes with very little prior warning and it can take a while to get them back. This happens with heat transfer from the pads to the pistons and into the fluid causing it to boil. You can have brakes when you get done with a race and sit still with the brakes applied and boil the fluid without moving because you caused the rotor and pad heat to transfer due to your foot on the brakes for an extended time.

Brake fluid is one area where you can run an uncompromising race fluid in your street cars with no negative effects. I run the Motul RBF600. It's not cheap but it has a high dry boiling point and the wet boiling point really stands out.

Pads will always be a compromise but they're getting better. Remember than "ceramic" may only have a little ceramic. I can't remember off the top of my head but I want to say the number is only around 20% to call the pads whatever material you want. If you want a pad with that works at higher temperatures for better fade resistance, they're going to make more noise, dust more, or not work well when cold or all of the above.

This is where the BBK comes in not just for someone who wants to go racing but for someone who wants to be able to drive hard with no brake fade and still have good street manners. With a BBK you don't have to go with an aggressive pad for fade resistance since the rotor will be running cooler. You can get the best of all worlds if you choose carefully. You can have the fade resistance of a race pad on the stock sized brakes with the good manners of a less aggressive pad. Of course, you can always run an aggressive pad with the BBK for track use.

Brake bias is very important and different replacement pads even on the stock brakes can cause a change in bias. Big brake kits have even more potential to change brake bias. Pads have a letter on the back to show their coefficient of friction rating. I can't remember what the stock pads are but I think the 5at is "FF". One letter is for friction when cold, the other is for friction when hot. It would be good to stick with the same rating.

A good BBK will retain the stock bias as well. With a large rotor you have a longer lever arm or more leverage on the axles. So the same pressure applied by the pads will stop the car harder and mess up bias, causing longer stopping distances. A good BBK will have less piston area in the caliper to compensate for the longer lever arm of the big rotors. Stoptech is the only one I know that does this and my measured stopping distances between the Rotora 13" kit and the Stoptech kit were huge with me modulating the brakes on the verge of ABS. The Rotora kit would give the ABS system fits and sometimes it seemed like it just gave up and refused to brake hard. The bite and release characteristics get seriously screwed up.

The goal of a good pad or a BBK is not to have the car stop harder for a given pedal pressure, if it does you probably screwed up the bias. A good kit will require the same pedal effort as stock. It makes me laugh when people say their new brakes make the car stop on a dime.

Last, you need a transfer layer, a layer of pad material on the rotor for the longest rotor life and best brake feel. If you have the pad scrubbing on metal you're going to wear the pads and rotors out quicker and you will likely have noise. To do this you need heat. Normally with a street pad there's plenty heat to lay down a layer of pad material but as you get into more aggressive pads you may notice noise or more dust as the transfer layer wears off due to the rotor not getting hot enough for the new pad's operating range. While race pads might work fine under race conditions, the street just won't produce enough heat for most. I've run a full race pad on the street and the noise even under light braking at 70mph would scare people. Rotor wear was rapid and the pads lasted about 6,000 miles. I could do 4-5 80-10mph stops and the rotors would be noticeably duller with the pad material deposited and the noise would go away for a day or two until it wore though the transfer layer again. Not fun. Luckily mine worked ok when cold. I've had some pads that I had to drag when I would pull out of the garage for a couple blocks to get enough heat in them to stop decently. That's why I went with the BBK, so I could run street friendly pads and still get good fade resistance.

I hope this makes sense, no time to read over it, got to go.

I hate cars

Drilling does not help cool the rotor at any speeds we're going to encounter on the street or any TL is likely to encounter and without brake air ducts.

Solid is always good choice. Slotted may or may not give better performance depending on the pad and usage but it won't hurt you either.

I've experimented with several different brakes including 2 BBKs on the TL. I've shot probably a thousand rotor and caliper temperatures on different brake combos and after different driving styles. I have friends on some very winning race teams but I still bought some of the SAE papers on this very subject, done in a scientific manner by unbiased researchers to help put some of the myths to rest. Now I'm gone lol.

Joneill44

Has anyone had problems with Brakemotive? For the price it seems hard to pass up

94eg!

Uh....what ^he said. lol

I hate cars

That's me typing as fast as I can, I'm afraid to read what I wrote lol.

masterstone

is all I asked. Yes that made sense, and thank you. Side note: Nice GN specs. My small project is a black/black '80 lesabre coupe - not going for track speeds but just to give it a refreshed drivetrain and some paint.

I hate cars

I wish I could edit. Maybe Mr Bell can merge this into that mess I wrote above.

Pad surface area... It makes no difference in stopping power. With the same clamping force from the caliper's pistons a large pad has less pounds per square inch of force but they have more overall area. It's a wash in the end. A small pad will have more psi but less area for the same overall clamping force. The advantage to a smaller pad will leave more of the rotor exposed for cooling. A larger pad can wear slower and possibly transfer less heat into the fluid. There are advantages and disadvantages to each but more or less stopping power is not one of them.

I also forgot to mention coherent vs abrasive friction. Coherent has the most friction and will produce the least rotor wear. It's when the transfer layer is laid down and it's mostly pad material on pad material. Abrasive is normal rubbing of the pad to the rotor. Both types of friction are happening when braking. From what I remember but I'm not sure, coherent can produce less heat but I'm not positive. Some say if the rotors rust quickly its because there's mostly abrasive friction but not sure about that. It makes sense to me.

I really need to take more time writing and organizing these posts but I never have the time. Plus I'm being forced to watch the bachelor.

I hate cars

Are you going with the 3.8 or 4.1 or one of the V8s? There's so much cheap V6 stuff in the junkyards. I got the 4.1L block, crank, and rods that are in the car now for $150. The cool thing is only the bore changes but everything else including crank heads and rods are identical. I cleaned up and treated the stock parts and stuffed it with some JEs and I had my ultra low budget 4.3L (.035 over) bottom end. The 4" bore let me use off the shelf Chevy V8 blower pistons which really reduced costs.

I hate cars

I mean 4.2L or 256".

94eg!

Sorry to confuse, but you don't get to choose between the various 100-series compounds. They have already choosen the compound in order to emulate the original OEM pad compound. That means if you buy the 100.10010 brembo caliper pads, you are only going to get the "low metallic" formula. But if you buy the 100.xxxxx for a Toyota Camry, your probably gonna get the "semi-metallic" formula. The idea of the 100 series pad is that it's a cheaper alternative to expensive OEM pads with the same friction material. For example, new Brembo 1001 shaped pads straight from Acura, Subaru, Nissan or Infinity cost at least $150 to $200 for the set. You can buy the Centric 100 series in that shape for only $60 with shims and the exact same friction material.

Here is more info on the 100 series pads: http://www.centricparts.com/index.ph...news&Itemid=66

masterstone

To be completely honest my shop teacher had a GN all original but rebuild and had a couple bolt ons, and if I could afford one (as a fun factor on top of my shovelhead) I would. Reality is my friend has a freshly rebuilt L48 or L82 (wikipedia helped as all I truly know is it was one of the better 350s from the mid 70s) and is willing to hook me up for cheaper than he paid. As well a recently rebuilt turbo 350.

In other news, my parts guy carries raybestos pads. I know he has the pro grade ceramic but I have heard they aren't anything special but get the job done. I will ask this morning if he carries the semi-metallic advanced tech pads.

http://www.amazon.com/Raybestos-ATD1.../dp/B00171M9V4

Anyone heard anything on these? good or bad. All I know is typically not giving a sweet **** I've gone with the raybestos pads before, and some other brand that (funny now that I think about it) said "nascar grade performance" on the box. I used to have a 95 caddy boat of a car and drove it hard. nearly 4000lbs of car stopping often in the city, they did last pretty well and my rotors didn't take too much of a beating.


--As this thread is probably going to die, thanks for the responses you two, hopefully in the future I get more of this, rather than that if you know what I mean.

I hate cars

I don't know about those particular pads so I can't help much. But keep in mind the TL is nose heavy when static and even worse under hard braking. That's why it has tiny solid rear disks. I'm going to see if there's a formula to get an approximate calculation of bias under hard braking but I would guess the rears do less than 20%. That leaves the fronts with roughly the same work to do as a 4,500lb car with a more normal weight distribution. I can't even track my full weight TL with a big brake kit without a more aggressive pad. That's why I always say the Brembos with the 12.2" rotors should have been standard with a 13.5" option. Obviously the Tl is only driven hard by very few people so I understand why they did what they did but I wish the optional Brembos would have been larger since mostly a performance oriented driver would go for them.

For what it's worth, my TL weighed about 3,700lbs without me in it and that's including a bunch of audio gear and sound deadening. It probably tips the scales at 3,500lbs without driver and audio so it's not too heavy for a newer car. My other car weighs 3,000lbs and gets by with 10.8" disks because of the light weight and almost 50-50 weight distribution.

NvrDwn

This is a quote from someone else, but it does a better job at explaining things than i can.

"
The friction between the pad and rotor is what causes you to stop. This friction converts your forward energy into heat (remember Einstein: Energy is neither created nor destroyed, it is converted). Now that heat is a bad thing. Yes it is bad for the rotors but it is a lot worse for the pads. A warped rotor will still stop the car - it will just feel like shit. Overheated pads however WILL NOT stop the car. It is here where the rotors secondary responsibility comes in. Its job now is to DISSIPATE the heat away from the pads and DISPERSE it through itself. Notice that DISSIPATE and DISPERSE are interchangeable? Once the heat is removed from the pad/surface area it is then removed. Notice where the removal falls on the list of duties? That's right - number 3. Here is the list again. Memorize it because I will be using it a lot in this post:

#1 Maintains a coefficient of friction with the pad to slow the forward inertia of the vehicle

#2 DISSIPATE the heat

#3 REMOVE the heat from the brake system

Let's look more in-depth at each step now shall we? No? Too bad assclown we are doing it anyway.

#1 Maintains a coefficient of friction with the pad to slow the forward inertia of the vehicle:
This one is pretty simple and self-explanatory. The rotor's surface is where the pads contact and generate friction to slow the vehicle down. Since it is this friction that causes the conversion of forward acceleration into deceleration (negative acceleration if you want) you ideally want as much as possible right? The more friction you have the better your stopping will be. This is reason #1 why BIGGER brakes are the best way to improve a vehicle's stopping ability. More surface area on the pad and the rotor = more friction = better stopping. Does that make sense Ace? Good. Let's move on.

#2 DISSIPATE The Heat:
Let's assume for a second that the vehicle in question is running with Hawk Blue pads on it. The brand doesn't really matter but that is what I am using as my example. They have an operating range of 400 degrees to 1100 degrees. Once they exceed that 1100 degree mark they fade from overheating. The pad material gets too soft to work effectively - glazing occurs. This means that a layer of crude glass forms on the surface of the pad. As we all know glass is very smooth and very hard. It doesn't have a very high coefficient of friction. This is bad - especially when I am coming down the back straight at VIR at 125MPH. Lucky for us the rotor has a job to do here as well. The rotor, by way of thermal tranfer DISSIPATES the heat throughout itself. This DISSIPATION lessens the amount of heat at the contact area because it is diluted throughout the whole rotor. The bigger the rotor the better here as well. The more metal it has the more metal the heat can be diluted into. Make sense? This isn't rocket science here d00d.

#3 REMOVE the heat from the brake system:
Now comes your favorite part of the process. This is what you thought DISSIPATION was. It is ok. I will allow you to be wrong. This is the step where the rotor takes the heat it DISSIPATED from the pads and gets rid of it for good. How does it do this? By radiating it to the surface - either the faces or inside the veins. It is here where cool air interacts with the hot metal to cool it off and remove the heat. Once again there is a reoccuring theme of "the bigger the better" here. The bigger the rotor, the more surface area it will have which means more contact with the cooling air surrounding it. Got it? Good.

Now let's look at why cross-drilling is a bad idea.

First - as we have already established, cross-drilling was never done to aid in cooling. Its purpose was to remove the worn away pad material so that the surfaces remained clean. As we all know this doesn't have much of a purpose nowadays.

Next - In terms of cooling: Yes - x-drilling does create more areas for air to go through but remember - this is step 3 on the list of tasks. Let's look at how this affects steps 1 and 2. The drilling of the rotor removes material from the unit. This removal means less surface area for generating surface friction as well as less material to accept the DISSIPATED heat that was generated by the friction. Now because of this I want to optimize step one and 2 since those are the immediate needs. If it takes longer for the rotor to get rid of the heat it is ok. You will have a straight at some point where you can rest the brakes and let your cooling ducts do their job. My PRIMARY concern is making sure that my car slows down at the end of the straight. This means that the rotor needs to have as much surface as possible to generate as much friction as possible and it needs to DISSIPATE the resulting heat AWAY from the pads as quick as possible so they continue to work. In both cases x-drilling does nothing to help the cause.

Now let's talk about strength - and how x-drilled rotors lack it. This one is simple. Explain again just how drilling away material/structure from a CAST product DOES NOT weaken it? Since you are obviously a man of great knowledge and experience surely you have seen what can happen to a x-drilled rotor on track right? Yes it can happen to a non-drilled rotor as well but the odds are in your favor when pimpin' bling-bling drilled y0! Since you are also an expert on thermodynamics why not explain to the group what happens to a cast iron molecule when it is overheated. I will give you a little hint - the covalence bonds weaken. These bonds are what hold the molecules together boys and girls. You do the math - it adds up to fractures.

So why don't race teams use them if they are so much better? Consistency? Hmmmm . . . no. I am gonna go with the real reason her chodeboy. It is because of several factors actually. They are as follows but in no particular order:

- Less usable surface area for generating friction
- Less material to DISSIPATE the heat away from the pads
- Less reliable and they are a safety risk because of fatigue and stress resulting from the reduced material

And what are the benefits? Removal of particulate matter and enhanced heat removal. I gotta tell ya - it is a tough choice but I think I am going to stick with the safe, reliable, effective-for-my-stopping needs solution Tex.

"

Also, from Wilwood's website:
QUOTE
Q: Why are some rotors drilled or slotted?
A: Rotors are drilled to reduce rotating weight, an issue near and dear to racers searching for ways to minimize unsprung weight. Drilling diminishes a rotor's durability and cooling capacity.

Slots or grooves in rotor faces are partly a carryover from the days of asbestos pads. Asbestos and other organic pads were prone to "glazing" and the slots tended to help "scrape or de-glaze" them. Drilling and slotting rotors has become popular in street applications for their pure aesthetic value.

I hate cars

That quote is EVERYWHERE on the internet and it's unfortunate because it has some errors. This is why I try to stay away from Google, I feel dumber after reading some of these things and from my search, just about every car forum has this posted, some made it a sticky and it's wrong wrong wrong.

"More surface area on the pad and the rotor = more friction = better stopping"

That is not true. Most surface area does not=more friction or better stopping. More surface area means less psi and it's a wash, not gain, not loss.

"The rotor, by way of thermal tranfer DISSIPATES the heat throughout itself. This DISSIPATION lessens the amount of heat at the contact area because it is diluted throughout the whole rotor. The bigger the rotor the better here as well. The more metal it has the more metal the heat can be diluted into. Make sense? This isn't rocket science here d00d."

Partially wrong again. He's talking of the rotor as a heat sink which it is initially but it becomes "saturated" pretty quickly and convection, conduction, and radiation are the only way to knock down heat, not the rotor mass. It might be slower to heat up but given enough time a heavier rotor will get just as hot. On the flip side it also cools off quicker. With the attitude this guy has he should do a little more research before putting others down.

"First - as we have already established, cross-drilling was never done to aid in cooling. Its purpose was to remove the worn away pad material so that the surfaces remained clean. As we all know this doesn't have much of a purpose nowadays."

I think he's the only one that has established that. Originally drilling was to let pad gasses out. The holes can clean the pads but that wasn't the original intent. It was gas along with weight.


"This is what you thought DISSIPATION was. It is ok. I will allow you to be wrong. This is the step where the rotor takes the heat it DISSIPATED from the pads and gets rid of it for good. How does it do this? By radiating it to the surface -"

I don't think heat is "radiated" to the surface. It just might be one of the other two and it's not convection lol.

"The drilling of the rotor removes material from the unit. This removal means less surface area for generating surface friction as well as less material to accept the DISSIPATED heat that was generated by the friction."

This goes back to his false belief that more surface area = more friction which is not true.

"Now let's talk about strength - and how x-drilled rotors lack it. This one is simple. Explain again just how drilling away material/structure from a CAST product DOES NOT weaken it? Since you are obviously a man of great knowledge and experience surely you have seen what can happen to a x-drilled rotor on track right?"

He needs to define strength because the rotors are not cracking for the reason he's alluding to. Drilled rotors are not going to flex or blow apart unless they have cracks and the cracks are not formed because the rotor is weak.

"
- Less usable surface area for generating friction
- Less material to DISSIPATE the heat away from the pads
- Less reliable and they are a safety risk because of fatigue and stress resulting from the reduced material
"

All 3 of his "main points" are incorrect.

-Surface area does not make a difference in stopping power.
-Less SURFACE AREA to "dissipate" lol heat away from the pads is the correct phrase but that wouldn't look nearly as negative as his wrong choice of words.
-Less reliable, yes, but not because of the reduced material.

"And what are the benefits? Removal of particulate matter and enhanced heat removal"

Removal or particulate matter, yeah, sure. Enhanced heat removal seems to contradict everything he's said so far.

TheChamp531

iTrader: (3)

Ah good ol ihc. Most informative posts on AZ

TheChamp531

iTrader: (3)

Ps brake motive rotors/ pads are awesome. Heavy traffic last week and had to do multiple stops and it was perfect. Don't judge BM because of there site as they have sold hundreds of kits to members here on AZ. It's like $160 for non brembo shipped.