Brembo rotors
Originally Posted by geminix3
triny-
i gotta say, i've come to side with gary on this.
stoptech, brembo, alcon, ap, dba- pretty much all of the brands i truly trust to know what they're doing with my brakes- none of them make a 2pc OEM replacement rotor, only full BBK's.
stasis was testing one awhile back, and after talking to beau at srm, i found that they came to the same conlusion that gary is implying, and that stoptech has verbalized at some point- they do not feel that a 2 pc rotor, *in the OEM size*, is capable of dissipating heat effectively in this application. period- too much mass is lost, and no amount of fancy vaning or anything else will make up for it. i gotta assume that's what everyone else has concluded as well.
stasis went with a BBK, using alcon calipers.
for my part, given what i've heard from multiple sources that i trust to know their sh*t, i'm automatically wary of any company which *does* produce a 2 pc OEM replacement rotor....
i gotta say, i've come to side with gary on this.
stoptech, brembo, alcon, ap, dba- pretty much all of the brands i truly trust to know what they're doing with my brakes- none of them make a 2pc OEM replacement rotor, only full BBK's.
stasis was testing one awhile back, and after talking to beau at srm, i found that they came to the same conlusion that gary is implying, and that stoptech has verbalized at some point- they do not feel that a 2 pc rotor, *in the OEM size*, is capable of dissipating heat effectively in this application. period- too much mass is lost, and no amount of fancy vaning or anything else will make up for it. i gotta assume that's what everyone else has concluded as well.
stasis went with a BBK, using alcon calipers.
for my part, given what i've heard from multiple sources that i trust to know their sh*t, i'm automatically wary of any company which *does* produce a 2 pc OEM replacement rotor....
alcon ap is stasis. ogvw said they stopped producing their rotors due to very limited interest in top tier performing stock replacement size rotors.
i don't understand why stoptech makes oem replacements for 350z then because they use the same brakes as us and weigh more in terms of touring package models (the ones that come with the brembos)
we had a thread here begging stoptech to make us some oem two peices but they didn't generate enough interest. they never said anything about thermal capacity.
additionally many people are using stock sized replacements with no ill effects and definitely with less fade especially when paired with a more aggressive pad, which is called for in performance driving.
i'm wondering how keeping a 1 piece rotor could possibly help performance driving... but perhaps someone can enlighten me. i do agree that the oem replacement 2 piece is not the end all of braking performance and that ultimately a bbk is the only way to stay fade free. particularly for a competitive racing type situation.
i'm not trying to argue really, just presenting what i've seen.
Last edited by trinydex; May 23, 2006 at 04:51 PM.
Then you most certainly have not seen the RacingBrake 2-piece rotors.
I personally am not impressed in-the-least with the factory brembo rotors for hard, track applications. I am also not impressed by the variation in craftsmanship from rotor to rotor, including thickness, finishing, etc. My RacingBrake 2 piece rotor set-up is so far superior to the stock system that is is laughable. I'm talking about heavy-duty hard use. I know that you work for Brembo, but if you claim that you have yet to see a two-piece replacement that is up to the Brembo standard, please quantify in what way you mean this. Even if you do not name manufacturers, give those other "unnamed" manufacturers a chance to outline the design and performance features of their rotors for comparison. The stock braking sytem on the evo is simply not up to the task of repeated, heavy, advanced motorsport usage. For the casual track enthusiast or the street enthusiast, yes.
I personally am not impressed in-the-least with the factory brembo rotors for hard, track applications. I am also not impressed by the variation in craftsmanship from rotor to rotor, including thickness, finishing, etc. My RacingBrake 2 piece rotor set-up is so far superior to the stock system that is is laughable. I'm talking about heavy-duty hard use. I know that you work for Brembo, but if you claim that you have yet to see a two-piece replacement that is up to the Brembo standard, please quantify in what way you mean this. Even if you do not name manufacturers, give those other "unnamed" manufacturers a chance to outline the design and performance features of their rotors for comparison. The stock braking sytem on the evo is simply not up to the task of repeated, heavy, advanced motorsport usage. For the casual track enthusiast or the street enthusiast, yes.
Originally Posted by Gary_BremboRT
trinydex,
I don't understand most of you reply. I'll try to answer the best I can.
My post was indeed mostly generalized information. In order to offer specific answers, and to offer specific and detailed performance benefits, would require specific information relating to a specific situation or circumstance.
I know it sounds like I'm running away from giving a specific answer but brake upgrades are usually a solution to a problem. If you're experiencing fade...we find the source of the fade and offer a solution. If you're warping rotors…we find out why and offer a solution.
First, the advantage of a rotor only upgrade is minimal, so I didn't have any answers that equal "shorter stopping distances"..."increased heat capacity"...or anything major like that.
Drilled rotors offer slightly better cooling, the ability to shed water during wet conditions, small amounts of weight savings, and some pad refreshing capabilities.
If drilled incorrectly or used in a very aggressive situation, you may end up with premature cracking. I would use drilled rotors if you need to find a way to lower the temperatures on the rotor and pad during street driving. Maybe if you've experienced fade from boiling your fluid. Every little bit of cooling helps n a street environment. This all adds to the performance of the brake system.
Slotted rotors constantly refresh the pad surface, improving initial bite and maintaining consistent coefficient of friction. They also help to shed water and keep the pad and rotor free of debris. I would use slotted rotors in a track or track like situation to maintain consistent pedal feel and bite. Also if you run a more aggressive pad that requires slightly high temperatures to function at an optimal level, a slotted disc tends to remain more consistent temperature wise. I would use slotted if you are glazing your pads or if you intend on running a more aggressive brake pad. This also ads performance to the brake system for a different circumstance.
I think you may have been looking for an over the top answer with huge claims for "performance". Allot of companies out there today are great at making huge claims about performance and not being able to back it up. I'd rather make minimal claims that I can guarantee and make sure the consumer is getting the product he is promised.
As for my comment about the 2pc rotors...I would rather not mention specific names. The purpose of this thread is not to "bash" or comment on any one else’s product. I have yet to see a 2pc. rotor offered for the EVO that matches the quality of even the factory 1pc. smooth rotor.Now, some of them do offer good amounts of weight reduction. And Brembo does not offer a 2pc. disc. So, if someone is looking to save weight, by all means, you can purchase any of the 2pc. rotors that are available.
Just keep in mind that (1) you are decreasing the thermal capacity of the disc (2) the quality of the actual disc portion may be lower quality and will most likely not last as long. That's why I mentioned that people should be sure to do more research than just accepting the claims of any particular manufacturer as fact.
Believe me...I love the 2pc. rotor idea for the factory Brembo calipers. I wish Brembo offered it for every vehicle that we produce OEM Brembo brakes for. It is one thing to chase the weight savings, but it is another when you are doing it by lowering the quality and longevity of the components.
Again, all of the claims about drilled or slotted rotors are dependant on the ability for that particular sized disc to be able to absorb and dissipate the heat created in a particular application.
I don't understand most of you reply. I'll try to answer the best I can.
My post was indeed mostly generalized information. In order to offer specific answers, and to offer specific and detailed performance benefits, would require specific information relating to a specific situation or circumstance.
I know it sounds like I'm running away from giving a specific answer but brake upgrades are usually a solution to a problem. If you're experiencing fade...we find the source of the fade and offer a solution. If you're warping rotors…we find out why and offer a solution.
First, the advantage of a rotor only upgrade is minimal, so I didn't have any answers that equal "shorter stopping distances"..."increased heat capacity"...or anything major like that.
Drilled rotors offer slightly better cooling, the ability to shed water during wet conditions, small amounts of weight savings, and some pad refreshing capabilities.
If drilled incorrectly or used in a very aggressive situation, you may end up with premature cracking. I would use drilled rotors if you need to find a way to lower the temperatures on the rotor and pad during street driving. Maybe if you've experienced fade from boiling your fluid. Every little bit of cooling helps n a street environment. This all adds to the performance of the brake system.
Slotted rotors constantly refresh the pad surface, improving initial bite and maintaining consistent coefficient of friction. They also help to shed water and keep the pad and rotor free of debris. I would use slotted rotors in a track or track like situation to maintain consistent pedal feel and bite. Also if you run a more aggressive pad that requires slightly high temperatures to function at an optimal level, a slotted disc tends to remain more consistent temperature wise. I would use slotted if you are glazing your pads or if you intend on running a more aggressive brake pad. This also ads performance to the brake system for a different circumstance.
I think you may have been looking for an over the top answer with huge claims for "performance". Allot of companies out there today are great at making huge claims about performance and not being able to back it up. I'd rather make minimal claims that I can guarantee and make sure the consumer is getting the product he is promised.
As for my comment about the 2pc rotors...I would rather not mention specific names. The purpose of this thread is not to "bash" or comment on any one else’s product. I have yet to see a 2pc. rotor offered for the EVO that matches the quality of even the factory 1pc. smooth rotor.Now, some of them do offer good amounts of weight reduction. And Brembo does not offer a 2pc. disc. So, if someone is looking to save weight, by all means, you can purchase any of the 2pc. rotors that are available.
Just keep in mind that (1) you are decreasing the thermal capacity of the disc (2) the quality of the actual disc portion may be lower quality and will most likely not last as long. That's why I mentioned that people should be sure to do more research than just accepting the claims of any particular manufacturer as fact.
Believe me...I love the 2pc. rotor idea for the factory Brembo calipers. I wish Brembo offered it for every vehicle that we produce OEM Brembo brakes for. It is one thing to chase the weight savings, but it is another when you are doing it by lowering the quality and longevity of the components.
Again, all of the claims about drilled or slotted rotors are dependant on the ability for that particular sized disc to be able to absorb and dissipate the heat created in a particular application.
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Joined: Apr 2006
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From: Long Beach
Originally Posted by hagakure
Then you most certainly have not seen the RacingBrake 2-piece rotors.
I personally am not impressed in-the-least with the factory brembo rotors for hard, track applications. I am also not impressed by the variation in craftsmanship from rotor to rotor, including thickness, finishing, etc. My RacingBrake 2 piece rotor set-up is so far superior to the stock system that is is laughable. I'm talking about heavy-duty hard use. I know that you work for Brembo, but if you claim that you have yet to see a two-piece replacement that is up to the Brembo standard, please quantify in what way you mean this. Even if you do not name manufacturers, give those other "unnamed" manufacturers a chance to outline the design and performance features of their rotors for comparison. The stock braking sytem on the evo is simply not up to the task of repeated, heavy, advanced motorsport usage. For the casual track enthusiast or the street enthusiast, yes.
I personally am not impressed in-the-least with the factory brembo rotors for hard, track applications. I am also not impressed by the variation in craftsmanship from rotor to rotor, including thickness, finishing, etc. My RacingBrake 2 piece rotor set-up is so far superior to the stock system that is is laughable. I'm talking about heavy-duty hard use. I know that you work for Brembo, but if you claim that you have yet to see a two-piece replacement that is up to the Brembo standard, please quantify in what way you mean this. Even if you do not name manufacturers, give those other "unnamed" manufacturers a chance to outline the design and performance features of their rotors for comparison. The stock braking sytem on the evo is simply not up to the task of repeated, heavy, advanced motorsport usage. For the casual track enthusiast or the street enthusiast, yes.
I think you may be misunderstanding my post.
First, I am not comparing the OEM Brembo system to an aftermarket upgrade. The OEM system is designed with a completely different purpose than a high performance upgrade.
Second, and as I have already mentioned...A brake upgrade is generally a solution to a problem...unless of course you are chassing aditional performance above and beyond what the factory system is capable of producing.
Your comment about not being "impressed in-the-least bit with the factory Brembo sytem for hard, track applications" lets me know you do not understand my post at all.
1) The OEM system was not designed for "hard, track applications." It was designed to offer a higher level of performance in street conditions to match the additional power and performance level that the EVO is capable of.
***The key points in this statement are OEM...and street conditions***
The factory wheels & tires don't fare well in "hard, track applications" either.
You can keep the factory wheels and upgrade the tires to offer better performance.
Same concept with upgrading discs, pads, fluid and lines.
2) Your comment leads me to believe that you some how exceeded the limits of the OEM brakes. This is not a difficult thing to achieve since the system was not inteded to be used on the race track.
***Remember when I said that "Brake upgrades are a solution to a problem"???***
You had a problem...you found a solution. That's awesome.
3) My comments have nothing to do with my working for Brembo. They are common knowledge to anyone who's been around the race track or has experienced reaching the limits of a factory brake system.
When you experience fade, you need to find a solution.
- If the fade came with a soft pedal, it is most likely fluid related. Change your fluid and upgrade to Braided lines. Maybe check the thickness of your pads. Maybe add titanium backing plates. Maybe add cooling ducts.
- If the fade came as a loss of friction, but still maintained a firm pedal, it is most likely due to exceeding the temperature of the pads or rotors. Upgrade to a pad with a higher temperature range, maybe add cooling ducts. If none of these work...a big brake upgrade is your last possible solution.
- If you warped your rotors...this is most likely due to exceeding the heat capacity of the discs. Start with less expensive mods like stated above or upgrade directly to a big brake system.
It seems to me that you found your solution to your problem. In your case it looks like a full front upgrade and 2pc. rear discs did the job. If your problem was exceeding the heat capacity of the factory discs, I highly doubt that any OEM size rotor replacement, 1pc or 2pc., would have solved you problem.
You decided to use "Racing Brake" as your solution. That's awesome. I personally have never heard of them but, I never said Brembo is the only option.
( I will keep an eye out and take a look at "Racing Brake's" products. )
I simply stated "I have yet to see a 2pc. rotor offered for the EVO that matches the quality of even the factory 1pc. smooth rotor."
***The key point here is quality...not performance. Anyone here will agree that a 2pc. rotor, and the weight savings as compared to the 1pc. disc, is definitely a possible performance upgrade.***
AND, If you read closely I ended both of my posts with "Again, all of the claims about drilled or slotted rotors are dependant on the ability for that particular sized disc to be able to absorb and dissipate the heat created in a particular application." Since you obviously were in a situation where the factory sized disc was not up to the task...none of my posts really pertain to your situation.
The funny thing is that I think you and I are almost trying to say the same thing. You used your experience as an example of a situationn where the factory sized disc was not up to the task,... while I made a genaral statement about drilled or slotted rotors in an application where they are capable of handling that task.
^
Because it is an important aspect. Unless you increase ducting, it is unlikely that the change of how one rotor manufacturer constructs it's inner pillars or hats vs another will have a noticeable effect on braking performance as it relates to temperature.
Each brand does its internal pillars differently - they need to to set them selves apart from each other in such a static world such as rotors. At the end of the day, they are all using iron disks, and there are only so many ways to get them to cool.
What you tend to find in the Evo is the stock pads are not a great match for the stock rotors, in track conditions. For street use, they work just fine. For the track, they tend to not last very long. But given that the car is designed as a street car first, it's a fairly simple upgrade to get awesome braking results. If new rotors are needed, there are lots of good ones out there as well. Stick to a reputable brand and you'll be hard pressed to do wrong.
And also, DBA does make a 2 piece replacement rotor for the Evo, as does AP (though they are tough to find, and I am not sure if AP spec'd out the hat themselves, or if a firm simply made their own, but I have a couple UK customers who run them on their cars). Project Mu, and Endless also make them The primary benefit the 2 piece rotor has, in a stock diameter, is weight.
The trick with the Evo, as with any car, is getting a set of pads and rotors that play nicely together for the conditions you use the car for. Add in some stainless lines and a good fluid, and you're golden 9 times out of 10.
Because it is an important aspect. Unless you increase ducting, it is unlikely that the change of how one rotor manufacturer constructs it's inner pillars or hats vs another will have a noticeable effect on braking performance as it relates to temperature.
Each brand does its internal pillars differently - they need to to set them selves apart from each other in such a static world such as rotors. At the end of the day, they are all using iron disks, and there are only so many ways to get them to cool.
What you tend to find in the Evo is the stock pads are not a great match for the stock rotors, in track conditions. For street use, they work just fine. For the track, they tend to not last very long. But given that the car is designed as a street car first, it's a fairly simple upgrade to get awesome braking results. If new rotors are needed, there are lots of good ones out there as well. Stick to a reputable brand and you'll be hard pressed to do wrong.
And also, DBA does make a 2 piece replacement rotor for the Evo, as does AP (though they are tough to find, and I am not sure if AP spec'd out the hat themselves, or if a firm simply made their own, but I have a couple UK customers who run them on their cars). Project Mu, and Endless also make them The primary benefit the 2 piece rotor has, in a stock diameter, is weight.
The trick with the Evo, as with any car, is getting a set of pads and rotors that play nicely together for the conditions you use the car for. Add in some stainless lines and a good fluid, and you're golden 9 times out of 10.
several things... i asked with the full understanding of all these factors. if you'd like a big visual archive of information you can check the rotor engineering thread in the advanced section.
pillar vane rotors found in the oem size 1 piece rotor are the worst for cooling. that said most two piece oem replacement rotors move to some sort of engineered vaning. this increases the mass of the rotor, particularly the section used for cooling AND absorbing heat.
altho a cast iron hat is a bigger heat sink... it does very little for actually cooling because it receives minimal air flow, the best that happens is that the air comes in the hat and out the hat, it'll never go through. using that part of the mass as a crutch for "cooling mass" is not what i'd consider technical or engineered.
the best thing the 1 piece rotor can do is conduct the heat away to the hub and the wheel. that's also not technical or engineered by my standards.
remember using real vaning technology increases the rotor's mass. i bet if you sawed off the oem hat and weighed an aftermarket rotor against it the results would be that the aftermarket rotors have more mass.
that said i DO BELIEVE that aftermarket two piece rotors are good enough for people seeking to track their cars with no more than 255 r compound rubber at all 4 corners and not exceeding 350hp. why? cuz i've seen it done. all of my track buddies have blackbos and many have successfully reached their level of performance at the track wtih oem sized replacements and race pads.
with that said if you wish to pursue anything beyond 255 and any more than 350 horsepower you need to seek larger brakes.
pillar vane rotors found in the oem size 1 piece rotor are the worst for cooling. that said most two piece oem replacement rotors move to some sort of engineered vaning. this increases the mass of the rotor, particularly the section used for cooling AND absorbing heat.
altho a cast iron hat is a bigger heat sink... it does very little for actually cooling because it receives minimal air flow, the best that happens is that the air comes in the hat and out the hat, it'll never go through. using that part of the mass as a crutch for "cooling mass" is not what i'd consider technical or engineered.
the best thing the 1 piece rotor can do is conduct the heat away to the hub and the wheel. that's also not technical or engineered by my standards.
remember using real vaning technology increases the rotor's mass. i bet if you sawed off the oem hat and weighed an aftermarket rotor against it the results would be that the aftermarket rotors have more mass.
that said i DO BELIEVE that aftermarket two piece rotors are good enough for people seeking to track their cars with no more than 255 r compound rubber at all 4 corners and not exceeding 350hp. why? cuz i've seen it done. all of my track buddies have blackbos and many have successfully reached their level of performance at the track wtih oem sized replacements and race pads.
with that said if you wish to pursue anything beyond 255 and any more than 350 horsepower you need to seek larger brakes.
Last edited by trinydex; May 24, 2006 at 01:36 PM.
Originally Posted by trinydex
dba does make stock replacments, 500whp sells them. i'm not fond of their engineering tho.
alcon ap is stasis. ogvw said they stopped producing their rotors due to very limited interest in top tier performing stock replacement size rotors.
i don't understand why stoptech makes oem replacements for 350z then because they use the same brakes as us and weigh more in terms of touring package models (the ones that come with the brembos)
we had a thread here begging stoptech to make us some oem two peices but they didn't generate enough interest. they never said anything about thermal capacity.
...
alcon ap is stasis. ogvw said they stopped producing their rotors due to very limited interest in top tier performing stock replacement size rotors.
i don't understand why stoptech makes oem replacements for 350z then because they use the same brakes as us and weigh more in terms of touring package models (the ones that come with the brembos)
we had a thread here begging stoptech to make us some oem two peices but they didn't generate enough interest. they never said anything about thermal capacity.
...
as far as stasis and stoptech, i do remember the threads at various times, but i'm going by what i've gotten from key people one on one, as well.
haven't talked to jason about it, but given what beau has said to me, i think it's likely that we had different perceptions of the situation. i doubt that what either one said was actually in conflict, just different conversations in different contexts.
i hear ya, really- i'm trying to argue either, i agree with you at least partly. this has just been on my mind, and i've been looking into it, since my stock rotors are about shot. i'm not really looking to go with a full BBK yet, just want to replace rotors. i've come to feel that simply changing rotors is unlikely to give any real performance gain on track, much more to be gained via increased cooling/ducting.
so really, i agree with you: no performance upgrade in a 1 pc replacement rotor. the only real difference between our opinions is my feeling that this applies to 2pc rotors also, and i haven't seen any real tech to prove otherwise (e.g., back to back rotor temp measurements, etc).
i've been studying the RB and PF 2pc rotors for a long time, but i just can't get beyond that sticking point. i look at the brakes like i do the chassis- far easier to screw up than improve upon- so why do all the brands i trust take a bye on this one?
long story, well, long, what gary is saying seems to correspond with what i've heard from other technical /manufacturer sources that i trust.
percy got good results with his upgrade- but, unless i'm mistaken, changed his whole brake system. am i wrong, percy? (by the way- we're nearly neighbors now, moved to roseville over the winter. look forward to meeting you sometime.)
and did you actually use the RB 2pc rotor before going with the BBK?
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From: Chicago
I appreciate all the info guys. I will simply go with OEMs because my car is practically stock and my problem is that my rotors are warped. I'm not really looking for performance rotors. However, I'm hoping these OEM rotors at least perform slightly better than the factory ones. Now I need advice on what would be more preferable. Cross drilled, slotted, or both? I drive mostly street but there are plenty of times where I drive fast and race every now and then. So I am skeptical on what style of rotors to choose from. Thanks
Originally Posted by trinydex
...
remember using real vaning technology increases the rotor's mass....all of my track buddies have blackbos and many have successfully reached their level of performance at the track wtih oem sized replacements and race pads.
with that said if you wish to pursue anything beyond 255 and any more than 350 horsepower you need to seek larger brakes.
remember using real vaning technology increases the rotor's mass....all of my track buddies have blackbos and many have successfully reached their level of performance at the track wtih oem sized replacements and race pads.
with that said if you wish to pursue anything beyond 255 and any more than 350 horsepower you need to seek larger brakes.
egad, i can't keep up with this- no argument here, and i'm curious once again about the RB's. i'll take another look.
but empirical evidence only goes so far- i earned my brownbo's (is that one less than a blackbo? i think so) on the *stock* rotors, after i vaporized my stock pads the first time i hit the track (literally crumbled apart as we removed them) and replaced them with DS2500's. the stock brake setup, with the right pad, is not as worthless as it's made out to be. i'd still like to see some controlled testing, and measurements taken, but that's never gonna happen...
i've got over 60k on mine, with ~10 track days, and nary a wobble or warp. they're spent, tho- and there's almost no paint left on my calipers. but they've held up.
always nice to discuss with people who actually think about this stuff.
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From: Long Beach
I fully understand the physics involved... and also the possible benefits of a 2pc disc vs. a 1pc. disc of similar size.
If I knew that the heat capacity was sufficient in both designs, and if I trusted the integrity of the components used to make the 2pc. disc...I would choose the 2pc. version without a doubt.
P.S. (I hope this is coming across as a fun and informative thread rather than a battle or confrontation)
With that said...
I want to disagree that the "engineered veining increases the mass of the rotor".
I think it is too general of a statement to make as there are too many other factors involved. The thickness of the disc plates and the air gap between them are a huge factor. The # of veins vs. the # of pillars. The thickness and shape of the veins also play part in that.
I cant say that you are wrong but there is not enough information to make this a general statement.
Air flow through the rotor is only one form of cooling...Convection.
There are also Radiation...and Conduction.
The first job of the brake disc is to convert kinetic energy into heat.
The second job of the disc is to dissipate this heat.
Before the job of cooling needs to be done...the disc must be able to absorb the heat produced. If the mass is not there to absorb the initial amount of heat additional cooling is irrelevant.
In the situation where the factory disc is already not efficiently absorbing and dissipating the heat, I would be hard pressed to recommend or upgrade to a 2pc. disc and loose the additional mass.
If you have not experienced any heat related problems then by all means, try a 2pc. disc for the weight savings, and even the ability to protect the wheel bearings from the heat transfer from the disc. (that's another benefit of 2pc discs no one has mentioned yet)
1pc. rotors are the industry standard.
??? I don't now what you mean by "not technical or engineered" ????
There are many ways to improve upon this design. I am not doubting that.
1) Improve to a 2pc. OEM size for the performance benefits as long as the mass of the disc can handle the job.
***As long as you trust the quality of the 2pc. discs that are available***
2) Improve to a larger disc (BBK) as a solution to a problem when the mass is not able to handle the job.
I'm sure there are allot of people out there that are perfectly fine with the 2pc. rotors. I personally had many people come to me when they are disappointed that the 2pc. disc did not solve the problems they were already having. And also a few that were extremely disappointed at the life expectancy of the 2pc. discs.
Most of this was due to:
1) Insufficient mass to handle the job
2) Poor quality rotors attached to attractive looking aluminum hats.
3) Hardware issues when rotors came loose during track like conditions
Agreed, most everyone can benefit from a full Big Brake System.
I just wanted to give the "buyer beware" message to those seeking 2pc. OEM sized rotor replacements when they are already experiencing heat related issues.
If I knew that the heat capacity was sufficient in both designs, and if I trusted the integrity of the components used to make the 2pc. disc...I would choose the 2pc. version without a doubt.
P.S. (I hope this is coming across as a fun and informative thread rather than a battle or confrontation)
With that said...
Originally Posted by trinydex
pillar vane rotors found in the oem size 1 piece rotor are the worst for cooling. that said most two piece oem replacement rotors move to some sort of engineered veining. this increases the mass of the rotor, particularly the section used for cooling AND absorbing heat.
I think it is too general of a statement to make as there are too many other factors involved. The thickness of the disc plates and the air gap between them are a huge factor. The # of veins vs. the # of pillars. The thickness and shape of the veins also play part in that.
I cant say that you are wrong but there is not enough information to make this a general statement.
Originally Posted by trinydex
although a cast iron hat is a bigger heat sink... it does very little for actually cooling because it receives minimal air flow, the best that happens is that the air comes in the hat and out the hat, it'll never go through. using that part of the mass as a crutch for "cooling mass" is not what i'd consider technical or engineered.
There are also Radiation...and Conduction.
The first job of the brake disc is to convert kinetic energy into heat.
The second job of the disc is to dissipate this heat.
Before the job of cooling needs to be done...the disc must be able to absorb the heat produced. If the mass is not there to absorb the initial amount of heat additional cooling is irrelevant.
In the situation where the factory disc is already not efficiently absorbing and dissipating the heat, I would be hard pressed to recommend or upgrade to a 2pc. disc and loose the additional mass.
If you have not experienced any heat related problems then by all means, try a 2pc. disc for the weight savings, and even the ability to protect the wheel bearings from the heat transfer from the disc. (that's another benefit of 2pc discs no one has mentioned yet)
Originally Posted by trinydex
the best thing the 1 piece rotor can do is conduct the heat away to the hub and the wheel. that's also not technical or engineered by my standards.
??? I don't now what you mean by "not technical or engineered" ????
There are many ways to improve upon this design. I am not doubting that.
1) Improve to a 2pc. OEM size for the performance benefits as long as the mass of the disc can handle the job.
***As long as you trust the quality of the 2pc. discs that are available***
2) Improve to a larger disc (BBK) as a solution to a problem when the mass is not able to handle the job.
Originally Posted by trinydex
remember using real veining technology increases the rotor's mass. i bet if you sawed off the oem hat and weighed an aftermarket rotor against it the results would be that the aftermarket rotors have more mass.
that said i DO BELIEVE that aftermarket two piece rotors are good enough for people seeking to track their cars with no more than 255 r compound rubber at all 4 corners and not exceeding 350hp. why? cuz i've seen it done. all of my track buddies have blackbos and many have successfully reached their level of performance at the track wtih oem sized replacements and race pads.
that said i DO BELIEVE that aftermarket two piece rotors are good enough for people seeking to track their cars with no more than 255 r compound rubber at all 4 corners and not exceeding 350hp. why? cuz i've seen it done. all of my track buddies have blackbos and many have successfully reached their level of performance at the track wtih oem sized replacements and race pads.
Most of this was due to:
1) Insufficient mass to handle the job
2) Poor quality rotors attached to attractive looking aluminum hats.
3) Hardware issues when rotors came loose during track like conditions
Originally Posted by trinydex
with that said if you wish to pursue anything beyond 255 and any more than 350 horsepower you need to seek larger brakes.
I just wanted to give the "buyer beware" message to those seeking 2pc. OEM sized rotor replacements when they are already experiencing heat related issues.
Last edited by Gary_BremboRT; May 24, 2006 at 03:32 PM.
HP has nothing to do with brakes though...the mass of the car, and the tire do (both in terms of compound and speed). Larger tires make the brakes work more efficiently, as there is more friction area to scrub off speed. But as I mentioned, at the end of the day, its all about a pad and rotor combo that plays nicely together for your given needs. If you do alot of hardcore track, it is money well spent, much like a set of proper R compounds. Essential (in my book no, but there is no question a BBK will take the abuse far better than the OEM's can, and that is the purpose of the BBK.
Totally agree on the pillar vane "technology". How much testing goes into this vs how much of it is just a "neat" design is subject to discussion I suppose. You'll never see the empiracal data the manufacturers use to determine the type of internal construction, and like I said, there has to be something that they can lay claim to to set them apart from rotor manufacturer B.
I've got customer after customer running normal 1 piece rotors (of various aftermarket brands), and most using Ferrodo DS2500 or 3000, on stock calipers with stock sized rotor. I personally do not feel that in a stock size, the 2 piece offers heat benefit vs a one piece. From a weight standpoint, yes they are better. How much it helps you? Very hard, if not impossible, to determine.
Can the stock rotor design be improved upon? I suppose it can. But if Mitsubishi, a company not exactly flush with cash at this point in history, finds the current design is adequate for the job they intend, they will stick with it.
On my Z (different car, but still)I have now gone through a set of AP rotors (mated to AP calipers and currently on Porterfield R4S pads). Had the rotors cut once, and got another 10k out of them, but they, and the pads, are now done and the couple hard stops and the brakes are toasted. I've not yet cracked a pad, or boiled the fluid, so for that reason, I am going to try a set of the DBA 2 piece units. I have never used their product before, but given the cost of the AP rotors, and the fact that I can get the DBA's for less, in a 2 piece, makes them worth my trying. I also will take the opportunity to upgrade to the Castrol fluid and probably try out the HP + or go back to the DS2500, which came with the brakes in the first place. Totally different car I know, but similar weight and similarly sized rotors.
Good discussion guys
Totally agree on the pillar vane "technology". How much testing goes into this vs how much of it is just a "neat" design is subject to discussion I suppose. You'll never see the empiracal data the manufacturers use to determine the type of internal construction, and like I said, there has to be something that they can lay claim to to set them apart from rotor manufacturer B.
I've got customer after customer running normal 1 piece rotors (of various aftermarket brands), and most using Ferrodo DS2500 or 3000, on stock calipers with stock sized rotor. I personally do not feel that in a stock size, the 2 piece offers heat benefit vs a one piece. From a weight standpoint, yes they are better. How much it helps you? Very hard, if not impossible, to determine.
Can the stock rotor design be improved upon? I suppose it can. But if Mitsubishi, a company not exactly flush with cash at this point in history, finds the current design is adequate for the job they intend, they will stick with it.
On my Z (different car, but still)I have now gone through a set of AP rotors (mated to AP calipers and currently on Porterfield R4S pads). Had the rotors cut once, and got another 10k out of them, but they, and the pads, are now done and the couple hard stops and the brakes are toasted. I've not yet cracked a pad, or boiled the fluid, so for that reason, I am going to try a set of the DBA 2 piece units. I have never used their product before, but given the cost of the AP rotors, and the fact that I can get the DBA's for less, in a 2 piece, makes them worth my trying. I also will take the opportunity to upgrade to the Castrol fluid and probably try out the HP + or go back to the DS2500, which came with the brakes in the first place. Totally different car I know, but similar weight and similarly sized rotors.
Good discussion guys
Originally Posted by geminix3
i'm not really looking to go with a full BBK yet, just want to replace rotors. i've come to feel that simply changing rotors is unlikely to give any real performance gain on track, much more to be gained via increased cooling/ducting.
so really, i agree with you: no performance upgrade in a 1 pc replacement rotor. the only real difference between our opinions is my feeling that this applies to 2pc rotors also, and i haven't seen any real tech to prove otherwise (e.g., back to back rotor temp measurements, etc).
i've been studying the RB and PF 2pc rotors for a long time, but i just can't get beyond that sticking point. i look at the brakes like i do the chassis- far easier to screw up than improve upon- so why do all the brands i trust take a bye on this one?
long story, well, long, what gary is saying seems to correspond with what i've heard from other technical /manufacturer sources that i trust.
percy got good results with his upgrade- but, unless i'm mistaken, changed his whole brake system. am i wrong, percy? (by the way- we're nearly neighbors now, moved to roseville over the winter. look forward to meeting you sometime.)
and did you actually use the RB 2pc rotor before going with the BBK?
so really, i agree with you: no performance upgrade in a 1 pc replacement rotor. the only real difference between our opinions is my feeling that this applies to 2pc rotors also, and i haven't seen any real tech to prove otherwise (e.g., back to back rotor temp measurements, etc).
i've been studying the RB and PF 2pc rotors for a long time, but i just can't get beyond that sticking point. i look at the brakes like i do the chassis- far easier to screw up than improve upon- so why do all the brands i trust take a bye on this one?
long story, well, long, what gary is saying seems to correspond with what i've heard from other technical /manufacturer sources that i trust.
percy got good results with his upgrade- but, unless i'm mistaken, changed his whole brake system. am i wrong, percy? (by the way- we're nearly neighbors now, moved to roseville over the winter. look forward to meeting you sometime.)
and did you actually use the RB 2pc rotor before going with the BBK?
percy did run the racing brake twi piece rotors, debuted them here http://www.norcalevo.net/forum/index...ic,6907.0.html
with a follow up here http://www.norcalevo.net/forum/index...ic,9544.0.html
yes i stalk you percy hahahaha.
but i know that gt40 used ap rotors on his setup and that might be one of the reasons why ap hasn't taken more initiative, becuase there's already stuff they make that works... and they don't care to openly advertise and seek out ways to "give" it to us.
basically... i would never tell any of my track buddies to buy brembo stockers or stocklike one piece rotors.
i would also advise them appropriately on which type of braking system to get for their grip and hp application.
Originally Posted by geminix3
i'd still like to see some controlled testing, and measurements taken, but that's never gonna happen...
Originally Posted by Gary_BremboRT
I want to disagree that the "engineered veining increases the mass of the rotor".
I think it is too general of a statement to make as there are too many other factors involved. The thickness of the disc plates and the air gap between them are a huge factor. The # of veins vs. the # of pillars. The thickness and shape of the veins also play part in that.
I think it is too general of a statement to make as there are too many other factors involved. The thickness of the disc plates and the air gap between them are a huge factor. The # of veins vs. the # of pillars. The thickness and shape of the veins also play part in that.
Originally Posted by Gary_BremboRT
Air flow through the rotor is only one form of cooling...Convection.
There are also Radiation...and Conduction.
There are also Radiation...and Conduction.
Originally Posted by Gary_BremboRT
ability to protect the wheel bearings from the heat transfer from the disc. (that's another benefit of 2pc discs no one has mentioned yet)