Ask The Expert: Braking 101 With Alcon

How far down the priorities list does upgrading your brakes come?

For many, braking is often overlooked or often misunderstood. Quite often it falls down the list in favour of adding more power, changing tyres or tuning the suspension, when in fact it can be a shortcut to both quicker lap times and/or more reliable, responsive and enjoyable fast-road driving.

Ask Alcon by Jordan Butters Speedhunters-101-9

OEM braking systems are designed to handle spirited road driving with stock power, and usually reliably and adequately so. But as soon as you start using your car on the track, or pushing up the power (more power = more speed), then before long you’ll start to find the limits of any OEM braking system.

Ask Alcon by Jordan Butters Speedhunters-101-2

Even when brakes are upgraded, many people follow the mantra that ‘bigger must be better’ and opt for the largest disc and caliper combo that they can get away with, with little thought to tertiary concerns such as weight, ventilation, compounds, lifespan, fade or feel.

There are many other variables to consider too, making it easy to install a system that isn’t working as efficiently as it should. Calliper design, disc design, master cylinder math, pad and disc compound, cooling, bedding in and so forth – they all play a big part in how your brakes work.

Ask Alcon by Jordan Butters Speedhunters-101-13

So much of the information out there in owners clubs and on internet forums comes from one person following the next, and quite often one upgrade is chosen over another simply because ‘that’s what everyone else fits’. Unfortunately, for many of us, garnering second or third-hand information from internet forums is our primary form of research. If only we had experts to hand who would be willing to offer advice…


Cue the lovely people at Alcon, who kindly opened up their doors to Speedhunters earlier this month. Now, the team at Alcon have offered to answer any and all braking questions you may have. Whether you want to know the difference between vented and grooved discs, what effect calliper piston count has, the do’s and don’ts of bedding in, a question about Alcon’s options for your car, or how to solve a specific braking issue, the floor is yours.

Your questions don’t have to be about Alcon products – their expertise extends into all areas of braking in OEM/aftermarket and motorsport too (as well as clutch systems), so fire away.

Leave a comment below with your name and your question and we’ll put the best questions forward.

Jordan Butters
Instagram: jordanbutters



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Amazing, Alcon brakes are definitely going on my car after these posts about them.


I recently upgraded my brakes from Stock 2006 Honda Accord to slotted rotors. After a hard stop the pedal starts to get soft. Am I overheating my brake fluid? Whats the best way to choose an upgrade for my needs that matches my rotor upgrade?


What pads? What fluid? Could be pad heating up, could be fluid boiling, could be rubber brake lines ballooning.
You can change your fluid to "super DOT 4", flush your system with fresh fluid when you change the pads. You can add ducting to help cool the brakes. You can upgrade to a more higher temp rated pad.


Did your try bleeding your brakes? Air is probably trapped in there, and when it heats up, it's compressable....


Yes. I had them professionally bled and they didn't find any air.


Agree with bleeding brakes yourself. This is something you want to be able to check personally and confidently and the only tools needed are a spanner, tube and a jar.
If you're not paying labour for service / maintainance you can spend on good fluid and preventative intervals.
Would advise getting a set of brake specific spanners and bleeding up with someone you communicate well with - get your "stop, ok, push, stop" pattern down :)


ive had good luck with bleeding with myself and a bleeder kit pump up the system and open the valve and it pulls the brake fluid through the lines just keep an eye on the level at the master way easy and you can do all the brakes by yourself,


Always check yourself! It's your safety, not theres!

There is an leak or air in the system somewhere though, as fluid is the last thing that gets hot. Normally brakepads glaze or rotors warp before brake fluid boils. A leak somewhere in the system is usually the culprit if air is absolutely ruled out.


Did you change your pads when you went to a slotted rotor? If so what pads did you choose? Are those pads suited for higher then stock/street driving? I'm guessing no.


Pads won't influence a pedal getting softer. Thats the wrong way of thinking. The brakes need to get red hot for that to happen.


Been there done that (on a race track). Yes, crappy pads will make your pedal go soft, but general street driving shouldn't. Usually it's fluid or rubber lines.


Will Alcon ever make a miata brake kit?


I'm guessing no because the Miata market is saturated at the moment. With the release of the StopTech ST42 kit for NA/NB's it would be tough to come into that market and sell enough kits to worth it.


Drilled, slotted, and grooved rotors seem to really only wear pads faster with marginal if not negligible gains in performance. How can we differenciate between the real performers from the gimmicks?


Depends on your other gear and needs. I run braded lines, Motul fluid and Ferodo DS2500 on OE Toyota discs and would only change discs for alloy hats (weight) not to add slots etc. Why? Cos I don't run the pads anywhere near outgassing / pad fade with 100hp and about 1000 of car so just don't need it.


I can probably answer this for your, but I have no affiliation with Alcon, but "just" a race engineer. Slotted/drilled/Grooved is just to evacuate heated air better. The more grooves/holes it has, the better the performance usually is. Do you need it? The most honest answer is: Usually not. You don't brake harderm but can brake more consistently over longer periods of time. For the streets unless your a maniac you won't need it. On track it's a option if brakes can only be of certain size to gain a few percent.

Gimmicks: In my opinion every brake disc that isn't round. Yes you get more brake area on the sides, but lose a lot more on the parts where it counts: The friction area....


Basically what I'm getting at. Also curious what Alcon has to say.

Another question for alcon, kevski too if you want. How often do you actually see a warped rotor vs a change in friction that causes brake oscillation. What scenarios have you seen this occur in a bench test?


The chances of a warped rotor increase when you are overloading your brakes. Hard braking without cooling them in between. But lets not forget leaving your foot on the brakes at a traffic light/in the pits.

But I actually think you mean the oscilation that you feel fom the grooves of the discs is it? In that case: Yeah, it's a known problem. Drilled or dimpelled is usually fine, as long as the holes are relatively small. If they are to big, or are drilled without stress relieving the holes (top and bottom is drilled slightly larger to round of the edges), because of stress fractures and extra friction that occurs otherwise, leave them for what they are. Thats the oscilation your getting. As for the grooves: They allways oscilate. And the same goes for cauliflower shaped brake discs to a lesser extent: Air friction because of positive pressure in the wheel wells tends to be fairly high. Shapes that are less airodynamic in nature tend to create more pressure.

As a side note on drilled rotors: Whenever those are worn beyond the point of the stress relieved point of the holes, you should expirience brake oscillation. By that point you can either drill them agian to relieve stress (If the discs themselves are thick enough), or just buy new ones.

And as another side note: Coarse brake pads. EBC Green stuff being a perfect example, but there are others. The coarser a brake pad the harsher they are for brake disc wear. But the exact opposite is true in heat buildup: The less friction your pads have, the more heat is produced when stopping in the same time. The reason: Surface area. A coarse brake pad tends to be made up of a rougher surface with higher peaks and lower valley's.


Kevski, I am more talking about when people think their rotors are warped, but really have lost a consistent friction embedment at the interface of the materials. When this happens on my cars, I can usually get rid of the "warped" rotor by redoing a break in procedure and starts to get better after about 10 hard decells. I want to hear about what scenarios cause this and any tips that may help alleviate the issue quickly versus having it diverge into worse oscillations.


This can be from pads that work by leaving residue on the disc and get that nice positive feeling when up to temp vs friction / abrasive type pads which wear the disc. In my limited experience pads like EBC / Endless etc will crumble where as good pads (in operation, price =/= good) will be more like the type that get a sticky feeling not a grinding feeling.


Oh, ok, thats quite simple actually: Your most likely glazing your pads. When you glaze your pads, it actually means that the pad surface gets to hot. Kind of see it like sanding stone: thats full of dirt. The dirt on your brakes is actually the pad itself. Most likely reasons for that to happen are: Overheating the brakepads. Either by stopping hard and often with inferior brake pads. Applying the brakes when you are at a traffic light and the brakes are still hot. A piston is stuck, so the pad keeps grinding on de brakedisc surface ever so slightly. Doing burnouts with the brakes tapped.

So all in all, unless you are trying toe replicate in, you won't find the answer in testing. It's just to much heat in the pads, as that isn't the rotor.

There is one other reason for that to happen, and its weather related: Rain. Or actually just water and its cooling properties: Whenever a brake pad is very hot and its cooled rapidly by water, it sometimes will happen that the brake pads crack. haven't seen it in ages though....


Dude I’ll stick with AP racing and Brembo, just shopped the alcons and man are those things grossly overpriced. Never heard of them till the other day and certainly wouldn’t pay more for them over AP brakes which I already know to be great. Seems like another overpriced piece to brag about on your similarly overpriced car.
Speedhunters is shill garbage these days


Have you used Alcon? Yes they aren't cheap but they aren't dress up parts either. Not every car needs you to spend the money but with one off purchases like calipers especially price is a negligible factor. I spend maybe $2k a year in tyres so getting the "right" calipers is something I won't cheap on.


Hard to take your opinion seriously if you've never heard of Alcon before


Nice try, people have opinions so get used to it. I’m just saying I wouldn’t pay a substantial amount of more money for brakes that are not used on near as many actual race cars as AP. Alcon is overpriced and no I hadn’t heard of them, EVER, and I’ve been around the industry in 10 years now.


Claiming to be in the industry for 10 years and have not heard of Alcon. That is a very questionable industry you're in. I am just an amateur, outside of the industry, only into the car scene in my parents garage during my college years. And I know Alcon. Either you're slow or, I am extremely fast.
Whenever people claim how many years of experience they have, it's bothers me a tiny bit. Just like the resume on the freshly graduated college kids.
I may agree with you on the pricing since they're expensive, and AP really is on many more race cars with reasonable price. But Alcon brakes are used on McLaren, Aston, Audi, WRC, Formula racing....
So I don't really know how to feel about your opinion. May be you need to update from Windows XP? haha
I am just kidding.


I race with a guy who won Le Mans and hes never heard of Alcon lmao.


Thanks for taking our questions team Alcon! What's your brake fluid of choice for daily driving and track days in a 5th gen Camaro 1LE? Is there such a thing as getting too much cooling air to steel brakes for track use?


Not associated with Alcon, but too much cooling is only bad if you're dropping below the lower operating temp of your pads, which will only be a concern for high temp race pads in fairly specific conditions. Even on a long straight, your brakes will retain a good amount of heat, not to mention slowing down at the end of that straight will pretty quickly bring your temps right back up. For the average driver on an average road course, you can never get enough cooling to the brakes.


I second that!

To low a brake temp only influences the initial bite an therefore first couple of meters. Running them to hot brings you in all kinds of problems: Warping discs, glazing brake pads, not to mention fire. And of course al the problems that start with the mentioned.

Unless you are within conditions you can monitor and control (as in: Racing on a closed circuit), I wouldn't recommend using pads that work from certain operating temps though. Street driving, even when driving like a maniac, is never predictable. So your brake temps aren't either. Why risk it, if you can brake better using brake pads that don't have a minimum operating range?


Can you advise if there's a big brake kit for the 1st gen Mazdaspeed 3 (2007-2009)? Preferably front and rear, with the factory handbrake retaining its functionality.
I know that Alcon made a front BBK for the 2nd Gen Mazdaspeed 3 (2009-2013) as I saw it on one of the many forums I'm a member of, but for the love of my life, I cannot find the part number anymore... :(
Cheers and thanks for the info in advance!



Hey sweet a fellow first gen owner.


two questions:
1. how do you calculate master cylinder size once you have changed to calipers with a bigger piston size or more pistons?
2. how do you calculate master cylinder size to account for removing the brake booster? (this one is for all the LS swap guys)


Easy: Volumetric displacement calculation: Calculate piston size of your callipers. Measure the hight the caliper Now you have the volume that needs to be displaced by each piston. That number times the total amount of pistons in every caliper. Now do the same for your master cillinder. Master cilinder displacement -Total volume of pistons . If it's a positive number, that means your ok. If it's a negative number, that means you need to upgrade your master cylinder.

So always get a master cylinder thats bigger then to total volume of pistons! if the master cylinder is way to big, you can always tone it down by ajusting the pedal linkage. But never go - .


interesting that you talk about volume, but given that pressure= force x area, you really haven't taken into account the change in pressure that would result in the lines other than saying adjust the linkage after (which isnt really possible on some stock brake pedals). I mean, i could increase the volume of a master cylinder by getting a longer cylinder or getting one with a bigger bore so it seems like it may be a bit more complex than you make it. I appreciate your enthusiasm but these questions were aimed at the Alcon people, who specialize in brakes.


Every pedal is ajustable: You just need to think outside the box: Force x lever is pressure. With force being equal (as in your foot), and pressure needs to change just change the control arm. (a.k.a the pedal lever) . I won't say its bolt on, but it is possible though.

There is one thing your forgetting: The above method is only needed for brake feel. Not for absolute braking power. Als long as it's bigger then it needs to be as just big enough its fine. The only difference is the amount of force you apply and how you can modulate the brake pedal. Brakes are still a mechanical system. Be it trough force of hydraulics or mechanical force.

And there is one other thing I am wondering though: If you ask about how to calculate it, which is a step beyond what regular people would know about brakes, how come your are making a fuss about which master cylinder is needed? You should already know that before asking the first question????

And no, I don't specialise in brakes as there is way more out there then just brakes. I am en ex-F1 engineer from the V8 era however. As in: Years ahead of whats available to the general public. And other then brake materials and how much holes can be placed in disc's there hasn't been to many changes....


to your question: your average person who is just bolting on a set of brakes may not need to know those answers but the people who track their cars and are on the entrance level may not know those things but would like to know. I also asked generally open ended questions so that i could see how Alcon chose to answer them, which can just be as telling as the answer itself. For example, you took a somewhat complex situation and dismissed it as easy without stating any assumptions that you were making both about the question itself and the intended audience. which leads me into my next comment:

Regardless of who you are and what experience you may have, the end point was that these questions were to be answered by a company that was vetted by Speedhunters as having the answers. Its kind of like if you were invited to give a talk at a show like PRI, and in the question and answer period you were unable to answer a question because someone else in the crowd was answering them. It doesnt really matter how much experience that person in the crowd has, the point is that they are not the experts that are being asked the question. In this case, you are just a random commenter on the internet who makes claims of having experience, It doesnt matter wether those claims are true or not because you were not the one asked.


Ok, I see where your coming from. But I'll try to explain my point of view: It doesn't matter who answers the question, as long as it's the correct answer. I was actually the one guy in the room who called BS and explained some thing in front of an audience in a local event. Does that make me bad? I think not, for having the correct answer. If a demented old woman gives you the correct answer, it still is the correct answer even though the experts says otherwise. There is nothing wrong with the correct answer, where ever it comes from. You or I might not like it, it may bruise someones ego, but thats life.

The one thing I do know is, even from the highest form of competitive motorsport there is, that it's always good to share the knowledge you have. As long as you make sure that it's the correct knowledge.

As for open ended qustions: So you actually have another agenda then just gaining knowledge? Then I would say shame on you if your question gets picked where others that actually need the answers don't.

As for giving you the correct answer: I'm terrible sorry! Won't happen again....


there is no other agenda other than gaining knowledge; evaluating how a company representative answers a question gains the knowledge of how they handle customer questions as well as their thought process and how they solve problems. Both of those factors are definitely in consideration when i evaluate which products to purchase when i look for upgrades. (it also seems that others are curious about the same subject in the comments below)

as for your point of view, it does matter who answers the question, it always does. How could I as a consumer even start to verify that you have given me the correct answer if i cant even verify who you are and that your claims to your experience are correct. To someone with less knowledge both the correct answers and wrong answers can sound equally truthful and thus the evaluation falls to who answers the question. Alcon has to deal with the liability that arises from their answers, thus they have a greater responsibility to provide correct and complete answers.

ps, the ad-hominem was a great touch. ;)


So, all in all, you actually mean that you are willing to listen to an incorrect answer if it comes from the "right" source, in stead of getting the correct answer from the "wrong" source? So that actually means that right is wrong and wrong is right? Only for the sole purpuse that you can sue someone? And then they ask whats wrong with the world today? Luckily I don't live in the States....

And yes, that "should" be the case. But how do you know they would? Your actually doubting everything I say although its all true. You can actually check it if you want. Just do the math, look up what I'm saying, test it out, whatever. It really isn't that hard....

And lets turn your point around: Is it possible that a company is biased towards its own products? Thats where indepents come in. And is it also possible to get financial gain if you get a biased answer? Thats where a business comes in.
Where as I don't sell anything and look at everything for what it is an give true answers? Not biased by all of the above? A company is there to make money. Thats how all companies work. Being bad at making money as a business is a recipe for disaster. And lets not forget that a sales rep isn't an engineer in the first place. It's just the guy who tries to make a sale. He isn't there for his in dept knowledge, but he's just there to make you buy stuff. Look at it like a Tell-Sell commercial.

And then theres the one point your missing: This topic is about asking questions to get answered by Alcon in a different topic. Roll that true your mind....

Oh and as for Ad Hominem: That actually means "On Man". It's "Argentum ad Hominem" ;) And that being said, I ask you this: For it being an Argentum ad Hominem I have to have made a false claim? If so, where? Try looking up Paul Graham and going down the pyramid with your own answers ;)


Kevski, u r on point. I have competed at high levels of Motorsports, and I appreciate your honesty. Too much secrecy, in our profession. Cheers.


Is it beneficial to switch from rear drum brakes to discs on a car with close to stock horsepower?
What are the benefits if any?


Thanks for your answers. I'll keep them.


I've had a Red Top BEAMS ST170 Corona and now have an ST190 Corona. Both are fine with drums on the rear (have done lines and pads in the front on OE calipers and discs). Both got engineer certified fine and never have problems on street or track.
Would rear discs look / be better? Maybe but when the existing setup has no failures / operates well I'll spend my time and $$ on a other bits of the car that need it.
Also the harder you're braking the greater the front bias so the less the rears are doing.


Depends on your goals for the car - drum brakes heat up quickly and don't cool cool very well, which is fine for daily driving in a light/low power car, but if you're taking it to the track you may find yourself overheating the rear brake shoes, which will shift your brake bias forward making you more likely to lose control under heavy braking.


Actually not that much of a problem as most people think, as long as the drums are in good working order. In a front wheel drive setup it's usually fine. I believe the latest Honda Civic time Attack car still uses rear drum brakes, although I could be wrong. On the track it usually equates to maxumum 10% braking power on the back in a light car, so drums are fine.

There are only 4 things you can do to improve drum brakes:
-Brake shoes with a higher friction coating: Usually custum made, heat up the drums quicker, but do give more bite.
-Brake drum with fins. Helps with cooling
-Brake ducting to help them cool
-Changing to disc brakes

Most of the time your actually fine with upgrading the front only an leaving the back stock.


When I do my rear drums I use new OE parts, commercial (Toyota van) pads which take the heat better and most importantly replace all the clips with double opposed high tensile clips. I feel that taking the slop / play out of the system so no parts are binding / rubbing does more for performance than and shiny name brand bits. OE+ all the way!


So does Alcon make any front upgrade kits for a Lancer Evolution 4? Ideally that can still be fitted under 16 inch wheels?



Thank you for taking the time in answering our questions.

In BROAD terms when designing brake cooling ducts, would it more efficient (in terms of overall cooling) to channel the cool air to the caliper itself or to the inner part of the rotor?


Not associated with Alcon, but most systems that will benefit from cooling ducts already have ventilated rotors, and the rotor is both the hottest part of the braking system as well as the largest heat sink, so routing the air into the center of the rotor is the most efficient method for brake cooling.


It's actually the case with every brake rotor. Having vented rotors on light cars is overkill and increases to much unsprung weight. But in doing so there is still heat buildup that needs to be dissipated.


What determines if a pedal box (with or without dual master cylinder) requires the factory brake booster, or may be used with no "assisted" braking? I see some racecars with and without factory brake boosters.


It actually depends on what you want to feel: I don't like brake boosters, because of the lack of feedback. But it is easier to brake because tit requires less force to press the pedal. So it's actually user preference only.


Hi, I drive a 2008 Bullitt Mustang that recently has seen some track use and will continue to in the future. The brakes on the car aren't ideal and even just on a small karting track were cooked after around 3 laps from ambient temperature. Its about time to refresh the brakes, so I'm considering upgrading to the 4 pistons brembos off of a later S197 Boss 302 coupled with DOT4 fluid, and stainless lines. There is no modification required to run this setup. I haven't decided on specific rotors or pads yet. The larger calipers and rotors would be front only. I test fit my wheels and tires on a 2014 5.0 with this brake setup, and they cleared - but with only about 1.5mm of clearance. I know that technically the wheels don't/shouldn't move on a plane that would cause contact, but it makes me slightly nervous anyway. Brembo recommends 3mm of clearance. I'd like to avoid running a spacer if possible. Would you guys say this is an acceptable clearance to run?


They shouldn't move in a physical sense, but there might well be expansion with heat


Please explain to people why wrong pads can damage a caliper with excess heat, example: carbon lorrain rc6 metal pads ruin Brembo Megane RS calipers becasues they don't dissipe heat!


Hi, I saw an RX7 parking next to the doorway in the first photo, Do you have the brakes upgrade kit for front and REAR of the FD? Which the parking brake will still be working. Thanks


Guidelines for sizing a brake system for a custom/heavily modified vehicle application. Rotors, calipers/piston size/qty, Front vs. rear, Master cylinder piston diameter. Love to hear some general pointers, areas of concern, rules etc. Much appreciated!


There isn't any straight up guideline to really cling on to. Way to many factors involved: Weight, weight distribution, tire compound, tire size, etc.


All my questions are in regard to track days, not the street.

Q1: Some people use Titanium shim between Calipers Piston and Pad to keep the heat from boiling brake fluid. How would this be optimized to prevent the pad from going into super heat cycle? There are ideas of letting other components act as heatsink, but how far do we isolate the heat?

Q2: 2-piece rotors (or floating rotors) are considered better. However, this would let the disc piece super heat and not being dissipated. How can we optimize this? Just use single piece rotor?

Q3: Modal analysis on the rotor. What is the acceptable resonance frequency (resonance mode) for the rotors in respect to car configuration in general?

Q4: May be everything above can be optimized with just simply brake duct to take advantages of all those above?

I am an Aerospace/Mechanical Engineer day time, so technical answer would be really appreciated.


Q1: It wouldn''t be a good for the pads. In general, pads have a backing of themselves just for that purpose. I would tell your friends to find pads that don't suffer the same problems.
Q2: Heat actually dissipates better with a hat. At least that should be the case. It depends on the material used for the hat iself. As long as you use a material with a higher heat dissipation rate, you should be fine.
Q3: Nice question. But it differs from car to car and is also depends on where the car is running in the world and on what surface. Way to much factors to give a decent answer to. Even if I would have the exact parameters involved I would still need to be on site to actually give resonable numbers.
Q4: Ducting is always a plus, except for one thing: Pads that have a minimum operating temperature. But I will give you some advice to sort out: How does the heat evacuate from the wheel well? Because you can also increase brake efficientie by letting air escape. Wheel arches are only needed in therms of reducing drag on the front and top side of the tire. Not on the back. So try looking into that first?


R u Chinese? Do u not know CATIA or Ansys? Do your own engineering.


Thanks! Useful response here. Great constructive reply, unlike the guy below:

Why are you so racist? hahaha What is your assumption that being Chinese or not would make anything more difference? I seriously worry about your future when "being Chinese" is the heavy cue factor for your professional work.
I learned CATIA and Ansys in school and use them at work. I don't do the analysis myself because company policy prevent me from using it for personal gains. So may as well ask because they obviously have done this already and I only needed to see the solution in relative to their studies. I am not into manufacturing or making copies. I am just personally curious to know the engineering behind it.
One piece of advise for you, may be looking at yourself in the mirror, think about yourself, and may be one day, one single day you will realize that somewhere out there outside of your computer screen, there are much smarter and faster people that you can learn from.


no i'm not racist. that was a joke. you can totally find 'copies' of Ansys that you can use at home. no excuses.


BUTTERS!!! lol if I buy this brake kit, what brake pads do I buy when I replace them? I've always wondered what would happen if I buy a big brake kit and need new pads. do I buy their pads? what if they are out of stock or the company doesn't exists anymore? I stay with OEM cause more people will make pads for those calipers. I understand OEM is limited but I still feel better knowing I can go to the local auto parts store to get some pads.


There are plenty of brake pad options for Alcon calipers.
Household names such as Ferodo, Endless, EBC, Project U, have pads that will fit Alcon calipers.

Currently using Ferodo DS2500 on my Alcon Extreme Advantage 6 piston calipers (CAR 97)


Running DS2500 on the street (car gets track time too) and love them!


I didn't know Alcon brakes were already on race cars like the new Vantage GT3


I've seen a lot of people opt for ducting air to move past the brakes for cooling instead of getting slotted or drilled rotors. Is this something worth looking into?


I understand both is the optimal under most circumstances but I've seen a bunch of people doing one or the other.


Both are made for very different purposes
If your rotors are vented, the air duct direct air into the center of the rotor, moving cooler air through the vents to cool down the rotors.
The slot are just to refresh the surface to keep the pad in contact with the rotor. Like a wiper.
The drilled are to escape hot gases on rotors in the early 90s, or if you're running carbon ceramic rotors like F1 cars. For modern pad technologies, the drilled holes are just for show; prehaps, even has negative effect by reducing the surface area of contact.


Dante R: Ever heard of centrifugal forces? If not: Try slinging around a bucket of water. Water stays in the bucket the harder you spin. Thats centrifugal force.

Air and fluid act the same way, so imagine a spinning brake disc. Those slots only move heat outward by removing it from the brake surface. Only when your moving very slowly or standing still this effect dissipates. But then again, so does the airflow in brake ducts.

Personally, I would opt for cooling the brakes via ducts, and not via slots or drilled rotors. The reason being that cooling via ducts has none of the drawbacks of drilled and especially slotted rotors. And at least the air can be used for something usefull.


I fully agree to what you just said. I would chose to use brake duct for cooling as well.
I didn't mention about the mass we're dealing with because the question brought up here was about heating issue.


Brakes are the first mod I did to my M3. Brembo 8 pot, wish I could afford some amazing Alcon items though! Horespower is useless without good tires and good brakes!


Hopefully, you track your car because 8pots are worthless on street cars.


Someone should tell Audi, as my car has 8-pots as stock…


Unless you want to do an indo at the stop lights! Lol jk but yes thats why I got them was to chip time off at the track. Also because I'm increasing the power 3 fold over factory so you have to be able to have anchors to handle it.


Uhm Joe, Have you actually ever used 8 pot calipers? They work just fine on the street. If you want you could even use 12 pots fine on the streets. They do not suffer from any drawbacks, except from unsprung weight. They Do tend to give better brake feel, but thats actually only the case if surface area is increased of the brake pad area.


who cares? you get better performance from a lightweight caliper. if you have money to waste, then do it. but, i would rather invest that money into something that truly matters.


The brake feel is so much better on the 8 pots over the factory single piston brake for sure!


I'm curious as to whether there is any meaningful discussion regarding staggered rotor sizes, or having the rear disc a few mm larger than the front, with the front running 4 piston and rear 2 piston. This is an off the shelf option for my car available from Stoptech, and they state that it is fine to run on track. What is a benefit or drawback to this?


Drawbacks: More unsprung weight, so more performance is lost meanly in the suspension department. I would actually never use bigger rear brakes then front brakes on any car, just for the fact that most braking is done by the front brakes anyway. It's just fysics.


Only time you consider a large(r) rear (were talking about brakes here) is on a rear engine vehicle but yes, the lionshare of your braking is done in the front.


Depends on your weight distribution, and tires. A 911 might benefit from more rear brake bias.


Not really, as even engine weight is shifted forward during braking. A square setup can have benefits in really special cases, but in most cases its just extra weight that you don't need....


you're just getting egotistical. what i said was totally on point.


does alcon sells products in philippines ? and for sentra b13?


When upgrading to a Alcon braking package, ie calipers, rotors and bells. Does the unsprung weight change make much difference to braking motion? is it something which is very overlooked?


It's relative to your stock brakes, and wheel hubs. Increased brake torque may cause unwanted deflection on a otherwise stock vehicle, causing issues like pad knock back. It's important to make sure your wheel hubs can handle the increased loads. 5-bolt hubs are a minimum.

Also, there are many other inefficient aspects of the stock brakes, that should be addressed before going to a brake kit. First, fresh fluid, and good pads. Next SS brake line, and MC brace. These are low buck mods, that will significantly improve any vehicle. If you're still not happy with your brakes, I hope you're on track, because you should not be driving at your braking limit on the street. Big brake kits are for track cars, they're a waste of money otherwise.


Number of studs has little bearing on the result. Squared, clean contact faces and even torque yes but I'd bet good money you can't detect the difference between 4 and 5 stud.
Also how do you figure higher torque = more knockback?


Uhm? Why are five lugs the minimum? You are actually saying that 5 lugs are always better then say 4 or even 3? It's more dependant on how heavy a car is, as the actuall torque doesn't come from the brakes themselves, but from the weight of the car. But lets say the weight is the same on both cars. one has 4 lugs, the other has five. Five lugs have a 8mm thick lug, 4 lugs have a 10mm thick lug. Which one is stronger?

All in all: Hubs aren't the area to be concerned about. It's actually the suspension bushings and to a lesser extent the wheel bearings.

The unsprung weight does make a change: Ride quality, acceleration, suspension performance. They all suffer accordingly. Actual feel differs to. But lets not forget that brakes are as good as the tires and suspension are. Upgrade them first before upgrading brakes. Unless your experiencing fade.... Overlooking unsprung weight: Yes, it's very much overlooked. But it al starts with wheels. Not so much getting lighter ones, but using smaller ones. As a rule of thumb I always say: Use as much tire height as you can, an as small a wheel that will fit around your brakes. Maybe not the best for looks (a matter of opinion actually), but it is the best for overal performance.


Okay, one weird one,maybe :)
How about upgrading drum brakes?
Or further, why change to rotors or do I need to for a better performance?

My case is a 76 Celica GT that should Keep the historic plate (Germany).


I had an older Corona, very similar to your Celica setup and if you do new OE rear setup (replace the press fit mild steel clips that hold the brakes together with double opposed high tensile ones) + good pads, fluid and lines on the OE calipers + new OE discs I think you'll be happy!
Most important isn't the biggest gear but to make sure that your car is set up to work well and not fight itself. Get everything clean straight and square. Tiny bit of copper grease on pivot / contact points and the better C clips take the slop out of the system.




While upgrading to aftermarket brake systems, is it important to keep the brake bias of the new system to be as close as possible to the OEM front/rear bias or it doesn’t matter and just let the electronics (eg EBD) to sort it out? Thanks.


It kind of depends on user preference, and what you wont to do with a car: More rotation = more front bias. Less rotation = more rear bias.


What about adjustable proportioning valves .


Thanks to all involved for this type of article. The writers, experts and editors time is much appreciated!


Hope i'm not late since i was AFK for the last couple of days.
As a reminder: Why we don't get "Raw Aluminum" brakes with the brand logo/name machined to the surface instead of painted calipers? Does the paint have any benefits?


Paint: Just one: Oxidisation inhibitor. Aluminum may not rust, but it still oxidises and gets dirty. Paint that is a good adition to calipers and disc is temperature paint. But only in testing. It discolorswhen reaching a set temp, zo you can see the temps it reaches.


Well, i forgot the oxidation part. Is a clear coat a good idea (if available) or the aluminum will have unpleasant looks and colors after "heat treatment"?


Clear coating: It will still oxides underneath it, so no, not really. Best bet is to paint it silver or any other color. And Remember to you heat resistant paint, otherwise it wil burn of.


Heck, so many people in here called Alcon XD