Advice needed on rotors

Manoogia86 · 07-01-2009, 09:33 AM

Does anyone have a suggestion for quality aftermarket rotors? I am looking at some deals on Ebay that seem pretty good, but am not sure if they are quality products. I would think that for the most part, any rotor would be good, but I am hesitant to buy from manufacturers that I havnt heard of.

Anyone see anything wrong with these?
http://cgi.ebay.com/ebaymotors/Chevy...Q5fAccessories

http://cgi.ebay.com/ebaymotors/06-07...Q5fAccessories

http://cgi.ebay.com/ebaymotors/Chevy...Q5fAccessories

I guess the safe bet would be these from tirerack...

http://www.tirerack.com/brakes/brake...ar=&perfCode=S

Thoughts from the pros?

**04DetroitLS** · 07-01-2009, 10:23 AM

http://www.r1concepts.com/
http://www.etopline.net/

have heard great things about both of these

**Dwayne J** · 07-01-2009, 10:33 AM

Cross drilled is a BAD thing for a street car. It can be useful in lightening a rotor in an application with BIG rotors for the weight of the vehicle and where they will get inspected and changed frequently. None of that applies here.

You could choose to believe the companies marketing over an enthusiast who bothers to UNDERSTAND how things work. Or you could get a clue and try to understand things yourself.

Porche in particular puts BIG brakes for the car size on, they drill to save some weight, but also them list specs as to how far the cracks can go before the rotor need be replaced. There is the detail everyone wants to ignore. Drilled substantially raises the likelyhood of cracking because it gives the cracks a place to start.

Another ignored detail is a rotor has to store the heat as it is generated and THEN it can shed that heat. Take metal out of the rotor by drilling and now you have less mass to store the heat meaning the brakes get HOTTER FASTER.

Do you honestly believe air if flowing through the drilled holes at speed too. What is there to cause the air to make a rapid 90 degree turn to go through the holes??

The aftermarket sells a LOT a JUNK meant to con you out of your money. Make an effort to truely understand things and your hard earned dollatrs will be better spent on GOOD parts instead.

Manoogia86 · 07-01-2009, 11:16 AM

Here comes Dwayne again thinking everyone is an ignorant fool

.

Relax Dwayne... I am here asking the opinions of "enthusi-assts" like yourself... If I was an ignorant asshole like you are making me out to be, I wouldnt be asking for advice in the first place, would I?

There are however truths to the advantages of drilled rotors. I highly doubt that you have a degree in physics, so if I were to believe anything YOU said, well... THAT would make me downright ignorant... afterall I dont know you from a hole in the wall... Here is how I understand it: When the brake pad grabs the rotor, it creates friction causing heat... am I right so far Dwayne? If that heat can't escape, it leads to brake fading, which decreases the stopping power of the brakes. Also, brakes and rotors get wet from time to time.... Wettness =

...slippery??? and slippery= uuuuhhh....no grab? (Boy this is hard) Having drilled holes on a rotor makes it easy for heat and water to be quickly moved away from the rotor surface, adding to brake performance. If you were as scientific as you thought you were, you would know that liquids, and heat (hot AIR, which is a GAS), are always trying to find more room to fill... this is not marketing bullshit, these are the scientific properties of liquids and gasses.... If heat (hot gas) is trapped between a ceramic pad and a metal rotor, wouldnt it be inclined to GET THE HELL OUT OF THE WAY and move to the cooler area in the drilled holes/slots?

The holes will reduce stopping power due to decreased surface area for the pads to grab, but, Im sorry Dwayne, this technology is NOT a load of bullshit. I have a hard time believing that Porche cuts out holes in their rotors SOLELY for the purpose of reducing weight... I mean really... a couple holes in the rotor would equate to a few pounds. That would not justify the added cost.

Manoogia86 · 07-01-2009, 11:17 AM

Quote:

Originally Posted by Dwayne J

Drilled substantially raises the likelyhood of cracking because it gives the cracks a place to start.

Every word of this is 100% true

But since when does heat need to be STORED before it can be shed? Heat can be stored in whatever molecules are around it, and the AIR surrounding the brakes stores heat just as easily, if not MORE easily than metal.

**Dwayne J** · 07-01-2009, 12:52 PM

If the rotor did not need to store heat we would be trying to make them thin/light as possible. They do need to store heat though so we have to make them thick and heavy to give them sufficient mass so they can absorb all that energy without getting too hot.

What the hell would this guys know?

**Internal Linking (Single Posts)

Halfway down the page he adresses drilled.
http://www.tceperformanceproducts.com/faqs.html

OCASSIONALLY you can find an honest business person, they endup running smaller shops. Big volume is generated by marketing not integrity.

**04DetroitLS** · 07-01-2009, 01:41 PM

Not a big fan of the drilled, slotted on the other hand seems to have its advantages... If cracking is such a big concern why not Kryo the rotors as a form of prevention? If you start w./ a good quialty rotors, you shouldnt have to worry about cracking as much as w/ elcheapo chinese blank.

good read on x/drilled & slotted rotors, I have to disagree on the Kryo stuff though, Maybe in brakes it doesnt make a difference, but i have seen a difference in trans hard parts on a T56 build....

http://www.superchargersonline.com/content.asp?ID=98

either way, if you choose to go w/ either the two companies listed have had great reviews from other Wbody owners, and use hi quality blanks (one of the two - cant remember which) has shipped rotors to customers houses in Bembro boxes, leading me to believe those are the blanks they use.....

Again, just my .02

Buffman · 07-01-2009, 10:13 PM

There are people with varying degrees in metalurgy, engineering, and so forth that do not agree with cyro'ing a part, or being to even understand how it works the way it works according to the company that sells it.

Drilled rotors are going to crack no matter what. Chamfering helps, but they will still crack. Cast holes are another thing, but NO ONE (there's a $200 reward for proof) makes a set of steel rotors with cast holes in them.

Manoogia86 · 07-02-2009, 07:53 AM

Thanks for the advice...

I guess a simpler way of phrasing my question is this: Are there some companies that make rotors that you would stay away from (drilled or not drilled doesnt matter to me). Like I said I am just weary of aftermarket parts from companies I have never heard of.

My father says "a rotor is a rotor and you cant go wrong... look for the best price" (Im sure he would stay away from drilled as well). But I am more skeptical, and wanted confirmation of that point.

My intention is not to go with drilled rotors necessarily, but I would like to get some aftermarket rotors that will be better than stock. I also have a feeling mine are mildly warped.

Belair427 · 07-04-2009, 08:30 PM

I am new to this forum but I have a little knowledge in regards to the question at hand. I have owned a muffler & brake shop for 24 years. I will have to disagree with dad on this one. Not all rotors are created equal. I would most definitely steer clear of the economy line of rotor regardless where you are purchasing it. I have a cut away of a premium rotor and a economy rotor that are cataloged for the same vehicle. Since Im new I cant post links but if you add the www to this you can view the pic.

As you can see the overall thickness is the same but the two rotor faces are thinner and the cooling fins are fewer on the economy rotor. This leads to decreased heat dissipation and can lead to pulsation. Now that being said lets discuss pulsation. Pulsation can occur due to a couple of different issues.
First is lateral run out which is more commonly refered to as warpage. This occurs, most frequently, when the rotor is overheated. There lateral trueness of the rotor can be explained as if you were to place a dial indicater at the 12 o'clock position of a rotor and set at zero. Lateral run out is the fluctuation from "0" in a 360 degree revolution of the rotor. if the variation is from .003 to -.002 this would be a lateral runout of .005 on this rotor. This condition usually will cause a steering wheel oscillation when braking. Most OE manufacturers allow as much as .006 in lateral runout.
The second is variation in parallelism. This can be described as if we took overall thickness measurements of the rotor at 6 equally spaced points around the rotor. ie 12 o'clock, 2 o'clock, 4 o'clock etc. If we get measurements from 1.025 to 1.131 thick, this would be .006 variation from parallelism. This will cause a pedal pulsation. Most auto manufacturers require no more than .003 variation (GM wants no more than .002 on the W body platform). Most economy rotors are .002 or more right out of the box. Why you ask is this so critical? If you are familiar with disc brakes you know how closely the pads run to the rotor. In a perfect condition the air gap between the pad and rotor when the brakes are not applied can be as little as .005. If there is a high variation from parallelism measurement in your rotor, every time the high spot rotated through the pad, pad material transfers onto that spot on the rotor, increasing the variation. Now the rotor that GM wants less that .002 variation in parallelism has had .008 pad transfer and, Oh by the way, we also fond out by measuring that we have .003 run out on the hub face while the rotor was removed. Lets add the .002 on the new rotor out of the box, .003 in the hub face and after a few thousand miles we transfered .008 pad material for a total of .013 when GM wants less than .002. This my friends is what is known as tolerance stacking.
This may be hard to follow but the long and short of it is be sure to buy brake components based on quality and not price. A premium rotor installed and trued with an on car lathe, followed by a premium pad set will give you the best performance. Oh and by the way, sometimes premium parts, install properly and be destroyed but poor driving habits like a two footed driver. Sorry for the length of my first post but I am passionate about what I do.

**04DetroitLS** · 07-05-2009, 06:04 PM

fixed so pic is visible ;)

07-01-2009, 09:33 AM	#1 (permalink)
Manoogia86 I was banned for stepping out of line, I was not the first, I will not be the last. Join Date: Mar 2009 Location: Trenton NJ Posts: 351 View My Garage Manoogia86	Advice needed on rotors Remove this ad! Does anyone have a suggestion for quality aftermarket rotors? I am looking at some deals on Ebay that seem pretty good, but am not sure if they are quality products. I would think that for the most part, any rotor would be good, but I am hesitant to buy from manufacturers that I havnt heard of. Anyone see anything wrong with these? http://cgi.ebay.com/ebaymotors/Chevy...Q5fAccessories http://cgi.ebay.com/ebaymotors/06-07...Q5fAccessories http://cgi.ebay.com/ebaymotors/Chevy...Q5fAccessories I guess the safe bet would be these from tirerack... http://www.tirerack.com/brakes/brake...ar=&perfCode=S Thoughts from the pros? __________________ Have you visited the Impala Forums Store today? Thousands of cars & parts for sale!

07-01-2009, 10:23 AM	#2 (permalink)
04DetroitLS Super Moderator Join Date: May 2008 Posts: 2,899 View My Garage 04DetroitLS	http://www.r1concepts.com/ http://www.etopline.net/ have heard great things about both of these __________________ any asshole can make a v8 fast It takes a special breed oof stupid/crazy asshole to make a v6 fast http:www.hellfiremotorsports.com/garage

07-01-2009, 10:33 AM	#3 (permalink)
Dwayne J Super Moderator Join Date: Jan 2009 Posts: 748	Cross drilled is a BAD thing for a street car. It can be useful in lightening a rotor in an application with BIG rotors for the weight of the vehicle and where they will get inspected and changed frequently. None of that applies here. You could choose to believe the companies marketing over an enthusiast who bothers to UNDERSTAND how things work. Or you could get a clue and try to understand things yourself. Porche in particular puts BIG brakes for the car size on, they drill to save some weight, but also them list specs as to how far the cracks can go before the rotor need be replaced. There is the detail everyone wants to ignore. Drilled substantially raises the likelyhood of cracking because it gives the cracks a place to start. Another ignored detail is a rotor has to store the heat as it is generated and THEN it can shed that heat. Take metal out of the rotor by drilling and now you have less mass to store the heat meaning the brakes get HOTTER FASTER. Do you honestly believe air if flowing through the drilled holes at speed too. What is there to cause the air to make a rapid 90 degree turn to go through the holes?? The aftermarket sells a LOT a JUNK meant to con you out of your money. Make an effort to truely understand things and your hard earned dollatrs will be better spent on GOOD parts instead. __________________ Dwayne 96 Caprice with AI 200cc package Best et 11.5 Best MPH 116 Just another taxi

07-01-2009, 11:16 AM	#4 (permalink)
Manoogia86 I was banned for stepping out of line, I was not the first, I will not be the last. Join Date: Mar 2009 Location: Trenton NJ Posts: 351 View My Garage Manoogia86	Here comes Dwayne again thinking everyone is an ignorant fool . Relax Dwayne... I am here asking the opinions of "enthusi-assts" like yourself... If I was an ignorant asshole like you are making me out to be, I wouldnt be asking for advice in the first place, would I? There are however truths to the advantages of drilled rotors. I highly doubt that you have a degree in physics, so if I were to believe anything YOU said, well... THAT would make me downright ignorant... afterall I dont know you from a hole in the wall... Here is how I understand it: When the brake pad grabs the rotor, it creates friction causing heat... am I right so far Dwayne? If that heat can't escape, it leads to brake fading, which decreases the stopping power of the brakes. Also, brakes and rotors get wet from time to time.... Wettness = ...slippery??? and slippery= uuuuhhh....no grab? (Boy this is hard) Having drilled holes on a rotor makes it easy for heat and water to be quickly moved away from the rotor surface, adding to brake performance. If you were as scientific as you thought you were, you would know that liquids, and heat (hot AIR, which is a GAS), are always trying to find more room to fill... this is not marketing bullshit, these are the scientific properties of liquids and gasses.... If heat (hot gas) is trapped between a ceramic pad and a metal rotor, wouldnt it be inclined to GET THE HELL OUT OF THE WAY and move to the cooler area in the drilled holes/slots? The holes will reduce stopping power due to decreased surface area for the pads to grab, but, Im sorry Dwayne, this technology is NOT a load of bullshit. I have a hard time believing that Porche cuts out holes in their rotors SOLELY for the purpose of reducing weight... I mean really... a couple holes in the rotor would equate to a few pounds. That would not justify the added cost. __________________ Have you visited the Impala Forums Store today? Thousands of cars & parts for sale!

07-01-2009, 12:52 PM	#6 (permalink)
Dwayne J Super Moderator Join Date: Jan 2009 Posts: 748	If the rotor did not need to store heat we would be trying to make them thin/light as possible. They do need to store heat though so we have to make them thick and heavy to give them sufficient mass so they can absorb all that energy without getting too hot. What the hell would this guys know? Internal Linking (Single Posts) Internal Linking (Single Posts) Halfway down the page he adresses drilled. http://www.tceperformanceproducts.com/faqs.html OCASSIONALLY you can find an honest business person, they endup running smaller shops. Big volume is generated by marketing not integrity. __________________ Dwayne 96 Caprice with AI 200cc package Best et 11.5 Best MPH 116 Just another taxi

07-01-2009, 01:41 PM	#7 (permalink)
04DetroitLS Super Moderator Join Date: May 2008 Posts: 2,899 View My Garage 04DetroitLS	Not a big fan of the drilled, slotted on the other hand seems to have its advantages... If cracking is such a big concern why not Kryo the rotors as a form of prevention? If you start w./ a good quialty rotors, you shouldnt have to worry about cracking as much as w/ elcheapo chinese blank. good read on x/drilled & slotted rotors, I have to disagree on the Kryo stuff though, Maybe in brakes it doesnt make a difference, but i have seen a difference in trans hard parts on a T56 build.... http://www.superchargersonline.com/content.asp?ID=98 either way, if you choose to go w/ either the two companies listed have had great reviews from other Wbody owners, and use hi quality blanks (one of the two - cant remember which) has shipped rotors to customers houses in Bembro boxes, leading me to believe those are the blanks they use..... Again, just my .02 __________________ any asshole can make a v8 fast It takes a special breed oof stupid/crazy asshole to make a v6 fast http:www.hellfiremotorsports.com/garage Last edited by 04DetroitLS; 07-01-2009 at 01:44 PM..

07-01-2009, 10:13 PM	#8 (permalink)
Buffman Senior Member Join Date: Nov 2008 Location: Michigan Posts: 191	There are people with varying degrees in metalurgy, engineering, and so forth that do not agree with cyro'ing a part, or being to even understand how it works the way it works according to the company that sells it. Drilled rotors are going to crack no matter what. Chamfering helps, but they will still crack. Cast holes are another thing, but NO ONE (there's a $200 reward for proof) makes a set of steel rotors with cast holes in them. __________________ Burnout! Exhaust Video Misc Video New ^^ Gone 7/12/09, but not forgotten :(

07-02-2009, 07:53 AM	#9 (permalink)
Manoogia86 I was banned for stepping out of line, I was not the first, I will not be the last. Join Date: Mar 2009 Location: Trenton NJ Posts: 351 View My Garage Manoogia86	Thanks for the advice... I guess a simpler way of phrasing my question is this: Are there some companies that make rotors that you would stay away from (drilled or not drilled doesnt matter to me). Like I said I am just weary of aftermarket parts from companies I have never heard of. My father says "a rotor is a rotor and you cant go wrong... look for the best price" (Im sure he would stay away from drilled as well). But I am more skeptical, and wanted confirmation of that point. My intention is not to go with drilled rotors necessarily, but I would like to get some aftermarket rotors that will be better than stock. I also have a feeling mine are mildly warped. __________________ Have you visited the Impala Forums Store today? Thousands of cars & parts for sale!

07-04-2009, 08:30 PM	#10 (permalink)
Belair427 Junior Member Join Date: Jul 2009 Location: Topeka KS Posts: 0	I am new to this forum but I have a little knowledge in regards to the question at hand. I have owned a muffler & brake shop for 24 years. I will have to disagree with dad on this one. Not all rotors are created equal. I would most definitely steer clear of the economy line of rotor regardless where you are purchasing it. I have a cut away of a premium rotor and a economy rotor that are cataloged for the same vehicle. Since Im new I cant post links but if you add the www to this you can view the pic. As you can see the overall thickness is the same but the two rotor faces are thinner and the cooling fins are fewer on the economy rotor. This leads to decreased heat dissipation and can lead to pulsation. Now that being said lets discuss pulsation. Pulsation can occur due to a couple of different issues. First is lateral run out which is more commonly refered to as warpage. This occurs, most frequently, when the rotor is overheated. There lateral trueness of the rotor can be explained as if you were to place a dial indicater at the 12 o'clock position of a rotor and set at zero. Lateral run out is the fluctuation from "0" in a 360 degree revolution of the rotor. if the variation is from .003 to -.002 this would be a lateral runout of .005 on this rotor. This condition usually will cause a steering wheel oscillation when braking. Most OE manufacturers allow as much as .006 in lateral runout. The second is variation in parallelism. This can be described as if we took overall thickness measurements of the rotor at 6 equally spaced points around the rotor. ie 12 o'clock, 2 o'clock, 4 o'clock etc. If we get measurements from 1.025 to 1.131 thick, this would be .006 variation from parallelism. This will cause a pedal pulsation. Most auto manufacturers require no more than .003 variation (GM wants no more than .002 on the W body platform). Most economy rotors are .002 or more right out of the box. Why you ask is this so critical? If you are familiar with disc brakes you know how closely the pads run to the rotor. In a perfect condition the air gap between the pad and rotor when the brakes are not applied can be as little as .005. If there is a high variation from parallelism measurement in your rotor, every time the high spot rotated through the pad, pad material transfers onto that spot on the rotor, increasing the variation. Now the rotor that GM wants less that .002 variation in parallelism has had .008 pad transfer and, Oh by the way, we also fond out by measuring that we have .003 run out on the hub face while the rotor was removed. Lets add the .002 on the new rotor out of the box, .003 in the hub face and after a few thousand miles we transfered .008 pad material for a total of .013 when GM wants less than .002. This my friends is what is known as tolerance stacking. This may be hard to follow but the long and short of it is be sure to buy brake components based on quality and not price. A premium rotor installed and trued with an on car lathe, followed by a premium pad set will give you the best performance. Oh and by the way, sometimes premium parts, install properly and be destroyed but poor driving habits like a two footed driver. Sorry for the length of my first post but I am passionate about what I do. __________________ Have you visited the Impala Forums Store today? Thousands of cars & parts for sale! Last edited by 04DetroitLS; 07-05-2009 at 06:03 PM..

07-05-2009, 06:04 PM	#11 (permalink)
04DetroitLS Super Moderator Join Date: May 2008 Posts: 2,899 View My Garage 04DetroitLS	fixed so pic is visible ;) __________________ any asshole can make a v8 fast It takes a special breed oof stupid/crazy asshole to make a v6 fast http:www.hellfiremotorsports.com/garage

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