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Drilled, slotted or both?

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Old 05-28-07, 06:24 PM
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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...
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Old 05-28-07, 07:17 PM
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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.
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Old 05-28-07, 07:22 PM
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Stick with slotted. X-Drilled crack.

Powerslots are supposed to be good.
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Old 05-28-07, 07:46 PM
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cross-drilled is going to crack, I would go with slotted.
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Old 05-28-07, 08:47 PM
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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.
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Old 05-28-07, 09:54 PM
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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.
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Old 05-28-07, 11:22 PM
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Originally Posted by sleepy91vert
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...
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.

Originally Posted by TitaniumTT
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?
No, I didn't realize that. What is your source for this information, and on which planet does it apply?
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Old 05-29-07, 08:15 AM
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cross-drilled is going to crack
X-Drilled crack.
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.

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?

Last edited by RotaMan99; 05-29-07 at 08:25 AM.
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Old 05-29-07, 08:21 AM
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when did 30 dollar brembo blanks go out of style?
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Old 05-29-07, 08:25 AM
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Originally Posted by Evil Aviator
No, I didn't realize that. What is your source for this information, and on which planet does it apply?
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

Last edited by Aaron Cake; 05-29-07 at 08:39 AM. Reason: Remove insult
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Old 05-29-07, 08:50 AM
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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.

Last edited by RotaMan99; 05-29-07 at 09:12 AM.
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Old 05-29-07, 09:12 AM
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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!
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Old 05-29-07, 09:13 AM
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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.
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Old 05-29-07, 09:18 AM
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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
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Old 05-29-07, 09:23 AM
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if you're driving around on the street, any rotor is fine.

On the track, I would stay away from drilled.
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Old 05-29-07, 09:24 AM
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stacking wheel spacers until they fit is absolutely absurd
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!

Big brake kit on the rear? WOW... I trully am at a loss for words.
You also read what I wrote after that right? Or do you not know how to read?

you used 12 ga red wire to ground your block yet you have a few electrical write-ups
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 ****. Weather proof your connections and you WONT HAVE AN ISSUE!

Also, removing mass from the rotor doesn't cause the pads to heat up.
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.

Last edited by Aaron Cake; 05-29-07 at 02:33 PM. Reason: Remove flame
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Old 05-29-07, 09:37 AM
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Originally Posted by RotaMan99
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!
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
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Old 05-29-07, 09:40 AM
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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.
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Old 05-29-07, 09:43 AM
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Holy crap boys take the laundry to the laudra-mat
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Old 05-29-07, 09:45 AM
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Sorry MOD and members, but when someone twists my words around, I have correct their misinformation.
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Old 05-29-07, 09:46 AM
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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!).
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Old 05-29-07, 01:19 PM
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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.
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Old 05-29-07, 02:34 PM
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TitaniumTT and RotaMan99, you've both had your say. Anything further and take it to PMs. Thanks.
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Old 05-29-07, 04:05 PM
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Directionally vaned two-piece rotors + proper ducting > all of your ricey machined OEM-style rotors any day of the week
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Old 05-29-07, 07:47 PM
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Both slotting and drilling improve cooling
They don't help with cooling at all.

Below is quoted from the link I provided above.
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.
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