Drilled, slotted or both?
 

I'm starting my project at the brakes... I bought new calipers all the way around and hooked them up with braided lines... My next step is rotors, but which ones??? I keep seeing slotted and drilled, yet I've read that slotted rotors wear through pads a lot faster... I'm thinking I'd prefer just drilled, but if both are better, well, I shall go with both...

I have tII calipers with drilled and slotted rotors and I love them. Easy to lock up with the emergency brake and the carwill throw you at the dash under hard braking.

Stick with slotted. X-Drilled crack.

Powerslots are supposed to be good.

cross-drilled is going to crack, I would go with slotted.

well Mazdatrix sells "Blank" rotors and you can get them drilled and slotted it costed me about $350 all the way around which did include getting them machined (slotted and drilled)

I've had absolutely no problems with them, they brake fine they cool fine they havent cracked, my pads are fine (hawk HPS) a little dust at the beginning, but it will go away after you fit the pads to the rotor, installation was easy except for the stripped screws and bolts..........

I say go slotted and drilled, i've had mine for almost a year now and i've had 0 problems with them.

You guys realize that x-drilled is designed to vent gases and keep "street pads" cooler when over working them while the slotted brakes are designed to heat the pads a little? So are you trying to keep street pads cool or heat up race pads? Oh wait, just bling.... no track.... nevermind.

Slotted, drilled, and slotted & drilled are all usually designed to have increased bite, which means a little more wear on the pads. Some manufacturers only offer drilled for low-level street driving in which the rotors will never be under enough stress to crack, while others only offer drilled for all-out racing in which the rotors are intended to be replaced before they crack. Some manufacturers recommend slotted rotors for racing. Therefore, you really need to check with the manufacturer in order to make a good choice.

No, I didn't realize that. What is your source for this information, and on which planet does it apply?

To say that cross drilled rotors WILL crack is wrong. This depends on the qaulity of the rotors and how many holes are driled in a line to sacrafice the integrity to the point of cracking. I have slotted and drilled rotors on my car from Irotors.com. They have 3 holes drilled in a row with a lot of meat between them and at the center and ends of the rotor. Personally, I don't reccomend getting drilled and slotted. Maybe just slotted. I find the best upgrade I did to improve braking on my car was the SS brake line. The rotors did very little with braking efficientcy.

Here is some info I found
http://forums.nasioc.com/forums/show...hreadid=368072

I once had the metal backing of the brack pad wear down the rotor to half its size and the rotor STILL did not crack. This was years ago, wont tell ya how it happend :) The rotor was only about 3/16" thick after.

I have had these rotors for about 4 years now with no problems except the one above and a slight manufactuer defect in one of them I got which will be swapped out under warrenty now that I have time to take my daily driver off the road.

:rolleyes:

when did 30 dollar brembo blanks go out of style?

When I was trying to decide on pads/rotors for my project I called KVR and spoke with one of the partners. Had a very very long discussion about the pro's/cons of each design of rotors and different levels of pads that they offer. More importantly the difference in the design and how pads need to be matched to the rotors. There's alot more to brakes then just buying a set of off the self rotors and whatever pads are rumored to be the best. That's called bling yo dooog.... I'd listen to someone with as much knowledge and experience as him. His resume was quite impressive. Don't believe me, call up yourself......

Oh wait that's right too, my best friend works for Race Technologies.... you know... the North American distributor for Brembo

Considering the more matieral you remove from the rotor, the less heat that the rotor will be able to absorb. So I suppose drilling and slotting or one over the other could cause the pads to heat up more. I can't see how ONLY slotting can heat up the pads. This could debated further since now that you have less friction area, the assembly could create less heat, but wont disipate as much heat. Bigger rotors would be better for brake cooling, since the rotor is the heatsink.

Daily driving or some spirited driving would never heat the brakes up to the point where you would have to worry about anyways. Why go to drilled and slotted in the first place since you are removing braking/friction surface. A better Idea then this would be to use the rear big brake kit on corksport.com. Although, if your rear brakes are stopping fine now, then don't get them since your rears may lock up before the front after the swap.

OEM bitches :)

Slotted? Drilled? Both? Who cares. Buy whichever you please or can afford. Neither is going to offer a noticeable amount of difference. Even on the track I doubt you'll notice much of one. Changing to DOT 4 fluid will give you a MUCH more noticeable change then a simple pair of drilled rotors will any day.

Buy what you want because unless we're talking FULL RACE, its bling.

That being said one of my 7's does have a drilled rotors. They look kewl sucka!

I always wondered about the necessity to use slotted/ drilled rotors on a street car. When you remove material from a rotor by drilling or slotting, you reduce it's surface area. Would this mean that it now takes more hydraulic force acting on the pads to achieve the same levels of braking as without mods? Are there double-blind test results that can be found somewhere that compares brake force, brake fade, heat dissipation, rotor warpage potential, etc? are most of you autocrossing or racing?....just really curious about all of this. Seems like more car manufacturers would offer their sports cars with these rotors if they were all that advantageous.

There is no polite way to say this so I am going to apologize to Aaron now - I apologize for what I am about to type... I will try my hardest to be polite.

Justin - You need to stop spreading mis-information. You really have no business attempting to speak intelligently on brakes. Your advice is often dangerous or completely wrong. For example - stacking wheel spacers until they fit is absolutely absurd. Also, removing mass from the rotor doesn't cause the pads to heat up. Not to mention why would someone put bigger brakes on the rear when they do a fraction of the work? That is wrong. Big brake kit on the rear? WOW... I trully am at a loss for words. You cannot comprehend physics enough, nor mettulurgy enough to even begin to comprehend all the different factors that combine to make an effiecent braking system. I lack the technical knowledge too. I leave that to the pros which is what I said, call them yourself. People who have been in the industry for 20 years, people who have worked on KART cars, people who design and test these products. Which is why my statement was simply that the rumors and all the other mis-information that is spread is tottally bunk. Unless there was a Brembo rep, or a KVR rep, or and EBC rep on giving advice, I personally would not take a lick of advice from anyone and then you have to think if they are just trying to hype thier own product. Brakes are designed to work together as a package. Just like putting race pads on stock rotors what do you think will happen? Do you know that there is a certain popular pad whoes dust is corrosive enough to damage clear coat? It needs to be left on for a long time but left uncleaned, it will actually bubble the clear?

This is only one of the reasons you were repeatedly banned from the other forum. You state your opinions as fact and they are, more times than not, completely wrong. For example, you used 12 ga red wire to ground your block yet you have a few electrical write-ups. You are the reason the internet cannot be trusted. I wouldn't take your advice for digging a hole and I seriously hope people read this, it doesn't get edited becuase the point here is don't take Rotaman's advice unless it can be confirmed by someone else with the technical know-how and a reputation on this forum.

But yes I agree, unless you are tracking the car they are mostly bling.... but I di auto-x so I needed a pad that didn't require warm-up yet I have experienced brake fade. I run a right pad with x-drilled rotors, ss lines and a good brake fluid. I have no complaints

if you're driving around on the street, any rotor is fine.

On the track, I would stay away from drilled.

You need to stop spreading misinformation and stop putting words in my mouth. I NEVER EVER said that. I said try different wheel spacer till they fit!

You also read what I wrote after that right? Or do you not know how to read?

2 12g wires and that is better then nothing that was there before. I don't have a problem with it, everything works, so why complain. Did you see me do a writeup on using 2 12ga wires as a ground between the firewall and tranny housing? NOPE! I like how you specified that I used red. Are you going to say that the color maters?

If Steve has seen the writeups, and hasn't changed anything or corrected anything, then what I typed coming from knowledge, is correct. I wouldn't take any advice from you on wiring thats for damn sure. You have been shot down before about wiring. you and your marine grade shit. Weather proof your connections and you WONT HAVE AN ISSUE!

Oh so your contridicting your self now? you said slots increase heat, that is removing mass. Doesn't cause them to heat up but to retain more heat. The less mass the rotor has, the less heat its able to absorb.

For the record - this will be my last post here

Don't ever question my memory or my integreity Justin. Post #5 http://forum.teamfc3s.org/showthread.php?t=52790

Again you can clearly see I did not say stack spacers. Adding spacers is not "stacking" spacers. It means adding different spacers till the fit.

Holy crap boys take the laundry to the laudra-mat :uh:

Sorry MOD and members, but when someone twists my words around, I have correct their misinformation.

To the OP - $30 brembo blanks work just fine. How much do you wanna pay for bling? Get better pads if you are really worried about stopping hard. I've personally seen drilled rotors fail (at an auto-x no less!).

Both slotting and drilling improve cooling. Both increase the chances of cracking your rotors. Drilling weakens the rotors a lot more than slotting. So slotting is generally preferred if you don't mind the higher cost. Or, if you don't need the added cooling, then the best option is neither. Cooling only becomes an issue after prolonged use of the brakes. For short-term braking performance, added cooling makes no difference whatsoever. Examples of prolonged use would include taking your car to a race track, or driving it downhill on a large mountain.

TitaniumTT and RotaMan99, you've both had your say. Anything further and take it to PMs. Thanks.

Directionally vaned two-piece rotors + proper ducting > all of your ricey machined OEM-style rotors any day of the week

They don't help with cooling at all.

Below is quoted from the link I provided above.

The guy you quoted also said this

2) The brakes function by converting the kinetic energy of the car into thermal energy during deceleration - producing heat, lots of heat - which must then be transferred into the surroundings and into the air stream

Do you really believe that?

here is the link again.

http://forums.nasioc.com/forums/show...hreadid=368072

Yes, that sounds about right. While I don't have any first hand engineering knowledge of brakes, that statement is at least the general principal behind braking.

Also, here is my recommendation for a street brake setup, assuming you have the 4-piston calipers:
Brembo blanks (or other quality OEM style rotors)
Hawk HPS pads (bar none the best street pad I have every used)
After that use a good quality brake fluid and make sure your lines are in good shape. Stainless lines are not generally recommended for street use due to the possibility of premature failure on the street. New OEM lines work just fine.

My personal setup currently:

4-pot brakes
Power Slot Cryo Rotors (Slotted)
Hawk HPS Pads (Will test Porterfield R4-S next)
Pennzoil DOT 4 Brake Fluid
SS Brake Lines

Started to fade a little during my last couple of runs, I'm thinking of switching to RBF600 before my next session.

Also, I agree with that warning about SS Lines, even though I currently run them. You don't want to have your brake lines suddenly fail on you.

Too bad racingbrake doesn't have anything for the 5 lug, 4-pot FC's!

Are you currently running a set of curved directional vane two-piece rotors? Where can I get some?

Neither. TII brakes with high performance pads. They don't fade (which is what you'd be going drilled or slotted for) and they stop just fine. Slotted wears away at your pads like an eraser, and drilled disks crack.

There seems to be a general consensus that "drilled rotors crack" and SS brake lines fail on a more regular basis than rubber lines, yet in nearly forty years of wrenching I've never seen either of these phenomena occur personally.

Long before you could buy drilled rotors (or they came standard from the factory) we drilled our race bike rotors and custom built brake lines and never had any problems.

Of course, as with any aftermarket part, there is good stuff and crap stuff and I wouldn't be surprised to see failure with the cheap parts but if braided lines and drilled rotors were so failure prone they wouldn't come as OEM on high performance vehicles- yet they do.

Naturally, this doesn't address the issue of whether a street car needs these race-inspired parts (probably not) nor whether the owner is even aware of the free bonus he gets from the rotors...that weird whirring noise that drilled rotors make under use.

I haven't tried thid on my 7, but for street use this combo has worked exceptionally well on other cars. Stock rotors unless you think drilled/slotted look sexy. Dot 4 fluid after a good flush. SS lines. Axxis Ultra pads.

Drilling and slotting to nothing for braking power, only braking longevity. Stock brakes in good condition should be able to do exactly the same thing. Anyone driving around the street in a manner where drilled and/or slotted discs are actually beneficial ought to be thrown in jail.

You would've got about the same result from using new rubber lines. Most of the benefit comes from getting rid of the old lines, not because SS is so much better than rubber.

That's exactly what the brakes do. If you don't believe or understand that you shouldn't really be taking part in a discussion about brakes...

i agree with rotaman99, i went to school for this stuff, basically, combo of pads and rotors for the type of racing that your going to do.... as far as rotor craking, if you abuse the with the wrong pads (race pads, hard breaking) even the quality products dont stand a chance....nice question though, this kind of threads stir everyone up.

I know this, since rubber lines weaken over time and expand more, which I don't know how many years of service they need to be used for before you notice anything, SS seems a better route since no matter how old they are, they wont expand.

If they are installed correctly and not twisted in any way, not even the slightest amount, you wont have an issues. I suppose it depends on what brand you get too. I have only seen Mazdatrix lines so thats what I got. 2 years going strong so far.

I don't do track racing with my car but my pads have been on for a little over a year right now with slotted rotors and there is still little over half the meat on the pads left. Also, I don't agree with the drilled rotor statment, this depends on factors that I mentioned above.

They also wouldn't come DOT certified :) Mazdatrix sell SS lines that are not DOT certified and they even say not to use them on the street.

Yes I do. All that friction causes a tremendous amount of heat and NEEDS to go some where, the rotor is the only part that can soak up the heat and transfer it to the air. The calipers will get the radiant heat and some heat that the pads transfer to it but the rotor is the first spot heat needs to go.

Drilling and slotting do the same exact thing as the other. There is no need to get both. I felt little gains from swapping the rotors on, the difference I felt was they seem to brake quicker. This could also just be me since I never paid attention to my brakes before I got the rotors.

Also no one drills holes in the rotors no more, its all cast. Which allows the rotor to be stronger then if you just drilled the holes.

Have you considered "dimpled" rotors?

I'm going to jump in here against my better judgement because you are doing it again. You are spreading misinformation and taking what is in your head which is WRONG and stating it as fact. NZ' Vert is absolutely right, you have no business in a conversation about brakes.... NONE! Very few of us do. Call the manufacturer of a QUALITY brake product, not powerslot or stop or any of those crappy companies. Get fact from people who build these things and actually do track testing and build them for professional race teams who actually need the product for more reason than oh cool you got blingy brakes...

If you don't do any tracking, you drive an N/A, if you're driving around on the streets in a manner that would require high performance (not just for looks which yours OBVIOUSLY are for if they are both slotted and drilled ) than NZ is right AGAIN, you should be in jail. Most of your reasons which you mentioned above are blatantly wrong!!! The machining thins the metal making it more susceptable to heat and cracking through less mass.


I have DOT cert CUSTOM brake lines on my car.... what's your point? You're looking in the wrong place.

They most certainly do not. They may both vent gasses but one is instended to cool pads the other is inteded to heat them. You are wrong.

Than why do you have both?

There you go again!!! Have you actaully called every single brake rotor manufacture and asked them how they manufacture thier own product? I highly doubt it. You CONSTANTLY speak your mind as fact & it is OFTEN flat out wrong. Those must be some really bitching molds though becuase the friction surface is just about always MACHINED when you get a new rotor isn't it?

It was said earlier and it was absoluetely correct - slotted rotors eat away at pads. There is a reason for that. It has to do with the design of them. I caution EVERYONE here when dealing with brakes, deal with the company and MATCH products to your application. Unless you are tracking your car, be it auto-x or actual track, you really don't need bigger or better brakes. Good OEM rotors and MAYBE some mild performance pads would be just fine. I track my car, I still went with a mild pad and x-drilled rotors. I went with the MILD pad becuase my car is still street driven so I don't want the noise, the dust and the nastiness but I need GOOD initial bite. Remeber that first turn in auto-x your brakes are pretty much stone cold.

Who made those?

Sure, they machine the braking surface but inside most aftermarket rotors certainly looks cast........:dunno:

*yawn* Search for the thread with my input in the racing forum...

Throwing my few cents (plus a Masters in materials science and 8 years working in stress, fatigue, and fracture in metals) into this- It doesn't matter whether 'drilled' rotors are actually drilled or whether the holes are cast in them, the potential issues with cracking and premature (compared to solid rotors) failure have to do with there being holes in the rotors period, not how they get there. Honestly you're likely better off with a nice shiny machined finish than with a rough casting since there's less likely to be a defect that could cause a crack to initiate and the rotor to fail. But having holes in the rotor means there's less area for the load (both physical and thermal) to dissipate over, and basic physics says that they're on average going to fail sooner than a solid rotor.

Granted, under halfway normal driving conditions, you shouldn't be causing enough stress on them to make that much of a difference between the two- but it's a simple fact that a drilled rotor will be more likely to fail sooner than an identical un-drilled rotor.

Aight, back off. I was speeking about daily driving. Did I say I was racing around town all the time braking hard? No I didn't. Daily driving plus some now and then spirited driving and my pads don't wear down real quick, this is what I was talking about, I was telling everyone that for daily driving, your pads wont get warn down as quick as they might when you are using them hard all the time. What the hell is your problem?

Ok MR smarty pants, tell me where I should look then? I have had them for 2 years and I can tell you I will have them for a LOT longer then that too. You have to install them correctly, they can't be twisted or have hard bends. Tell me im wrong here and then call mazdatrix and prove your self wrong.

So you settle for one persons opinion? Nice.

When I bought them 3-4 years ago I didn't do the research I should have. So I am telling others what the results were on MY DAILY DRIVER!

No, show me a company that sells drilled rotors, where it says they are selling rotors that are drilled with a drill press or any other method. The majority of rotors sold are all cast.

They don't eat them away at an alarming rate while using them on the street! This is what I am saying! Read!

Show me where he said that.

Correct, im saying if you drill holes in your rotors and don't drill them correctly, you risk putting microscopic cracks in the cast or chipping which can weaken them even more.

TT, this whole time you have been stretching my statements to mean something completly different then what I intended the statements to mean. Back off!

That was actually for someone else...

Holes in the rotors are stress concentrations so will increase the likelyhood of cracking, it doesn't guarantee it, but it increases the odds.

Drilling removes mass and therefore thermal capacity from the rotors, which means that for a given heat addition they'll get hotter.

Pads outgassing hasn't been a problem for a long time now. Any good source will tell you that.

Racing pads on stock rotors works just fine. You can get a full set of rotors from places like NAPA for under $100 that work just fine, even on track (personal experiance).

Look at the brakes in the paddock of a race track on a race weekend and you'll see that 95%+ use plain, undrilled, unslotted rotors.

i had drilled and slotted rotors on my old civic and it cracked straight through where the rotors were drilled at.

Love Fest!
 

Holy smoke! :shocking:

Connecticut and New Hampshire are pretty close to each other. Why don't you lovers just meet up and settle your differences the old fashioned way? :tank:

Seriously, your ongoing hatred for each other is not contributing to the forum. You are both better that this...

A) That's becuase the rotors you have are useless. Seriously no performance rotor will have both, totally negates each other. The slotted are designed to shave your pad each pass to build and keep heat and by doing that they are eating away at your pads
B) You know what my problem is.

Again, you're not reading, I said a few different sources, not just one.

So how much research have you done after the fact? How many people have you spoken to in the industry. Have you been on the phone with someone as they are assembling a $9,000 brake kit? I don't think so. You are giving people your opinion on a daily driven car that you admitted to NOT doing the research on. You are spreading WRONG information and passing it off as fact.

Well of course they don't because the rotors you bought are designed for ONE thing and ONE thing only...... BLING!!!!! Slotted rotors from a reputable company that are designed to function will eat away at your pads... PERIOD! By your own admission you didn't do the research, by your own admission you have rotors that serve no functional purpose yet you still tout your opinion as the end all be all and that bothers me becuase if no one else had jumped into this thread the OP would have listened to you and bought a useless product.

From the horses mouth - My best friend in the world I told him to read this tread to get a laugh. I asked him to write a few things for me to post; here's what he said.
Hmmmmm... Mis-information... Really pal... you don't say. Are you saying something on the internet is not true. Oh Lord Save Us!!! He's in the industry and has been for some time now. Plus, he's been an enthusiast for as long as I have been, which is ~15 years starting with the ole drivers license.

FWIW here is his M3 Comp Edition - Total overkill and he know's it, but it's a rolling advertisement
Front = 380mm disc, 6 piston monoblock
Rear = 345mm disc, 4 piston 2 peice

http://forum.teamfc3s.org/attachment...5&d=1180721653
http://forum.teamfc3s.org/attachment...6&d=1180721653

I'm NOT giving out his work e-mail but if someone seriously wants to talk to him, PM me.

whoa ,9,000$ ....for brakes ....just slot your rotors...dont make holes in them ... there prone to cracking in high temps..

"the process of drilling rotors and slotting rotors was done for 1 reason and 1 reason only it is to disipate the gases that build up between the pad and the rotor which occurs under extreme heat ( when braking very aggressively like on a road course) and it has absolutely nothing to do with heat disipation."

this was quoted earlier in the thread. Did I miss something? Heat has gas-like properties. Dissipating "gases" is actually dissipating heat. A drilled or slotted rotor is like a heat sink, more surface area= more cooling. One thing though is that it is very hard to resurface drilled or slotted rotors, may or may not be an issue for you...

You did not read or are trying to twist my shit around again. I said 3-4 YEARS AGO I didn't do the research on them which is why im letting people know that for a daily driver, drilled and slotted rotors are not going to do you any good! What are you trying to prove?

This is 100% bull. Slotted is slotted. The slots on my rotors have a bunch of brake dust and crap in them. Even if I bought $9000 slotted rotors with cheapo brake pads which I use, they still wouldn't get eaten away because I am not using them in the fashion they were designed to be used in.

Again, your twisting my shit around and spreading mis-information. If the OP read my posts, he would have read that I noticed NO DIFFERENCE with the rotors on MY daily driver. He would have also read that I noticed more of a difference with SS lines. Wait wait, let me make this very clear so you possible can't twist it around, read word for word, or is that still hard for you? I - did - not - say - to - the - op - to - get - stainless - steel - braided - lines - instead - of - oem - hard - rubber - lines. Never said he shouldn't get brand new OEM ones and only get SS. I said I noticed a diff with MY SS braided lines compaired to the no difference I found with my rotors.

Where did I ever say to the OP to GET these rotors? SHOW ME! SHOW ME! SHOW ME! O wait, you will make something up just like that e-fan thread when I said I don't have a belly pan and I don't have an issue and you ASSUMED that I ment you don't need a belly pan at all when that is not what I ment at all in any fashion.

Stop twisting my words around, your making your self look bad.

What are these pictures supposed to prove? Im sure I can go online and find some really nice cars with the same brakes or different brand of brakes that look better or just as good.

Wrong again. That's so blatantly wrong I laughed so hard both my dogs came running in to see what in the name of all that is holly was wrong. (They found the humor too ;))There is, I'm SURE, even though I'm just speculating here, a very big difference in the way your Irotor.com things are slotted compared to any number of differenet REAL brake company products. How is it that the slotted's run so much hotter? hmmmmm???? Do you honestly think that Irotor has the technology of any number of different manufacturers? Hell man, why doesn't IRL buy their shit from Irotor??? :uh:

Don't you DARE, don't you EVER accuse me of spreading mis-information. How much of your crap should I link? I'll be the first to admit when I don't know the answer to something yet you constantly get into every thread you can to give bunk info. The freaking wheel thread: Justin's Answer: I don't know, keep adding (STACKING) them until they fit. :icon_no2:
You don't know yet you vomited dangerous garbage on the net that someone might have actaully followed.

So you openly admit to buying a usless bling product to impress the great people of NH with. That's a good start.

:rlaugh: :crackup: :rofl: :hah: :lol: :lach:

FWIW = proves nothing.... here's a pretty pic, here's what the guy who can have just about any braking product he can get has. I also said, "Total overkill..... rolling advertisement." As for finding something better for an M3.. I promise you, you can't. One off kit :bigthumb: When you make a product that actaully preforms a function people buy it. When ALOT of people buy your product you can drop $7,000 into a rolling ad. Me, I put 10% of that into my brakes and it's just fine becuase I actually did some freaking research before I spent some $$