Replacement rotors - blank face
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FWIW, if you're not too hung up on minimizing rotational inertia, just wanting to have some OEM grade rotors for abusing and using up, the Winhere's did wonderfully matched up to some DTC-60's at a HPDE at Gateway. GIR is a HP track, not tons of repetitive braking, but three very hard braking spots in a 1.6m track. The Winhere's are as heavy as OEM, but for $200 all four, delivered, I can't think of a better budget track setup for brakes. Yay!
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FWIW, if you're not too hung up on minimizing rotational inertia, just wanting to have some OEM grade rotors for abusing and using up, the Winhere's did wonderfully matched up to some DTC-60's at a HPDE at Gateway. GIR is a HP track, not tons of repetitive braking, but three very hard braking spots in a 1.6m track. The Winhere's are as heavy as OEM, but for $200 all four, delivered, I can't think of a better budget track setup for brakes. Yay!
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Sorry, I abused them in one short week. Well, they looked different right after the bed in. After bed in with racing-pads, they developed as expected a bluish tint, most noticable in the center. They were definitely noticably double ground. I'd not really give a perfect answer on the Centric types and differences. If I had to guess, "Standard" OEM grade. I pulled them and the racing pads off tonight (Getting good, four wheel rotor and pad swap out, less than 2 hours with all hand tools and floor jack), and they still look so much nicer than the 2 year old OEM. I'm thinking I'll get as many events using these as the pads will last. I think I like that proportion, both for budgeting as well as overall "karmic balance" 
Pads look awesome, good thing considering they cost over $400 and I only drove them for a week! Nothing untoward indicating bad wear from rotors. Rotors same, nice.
I used my temp gauge on them after one cool down lap, jumped out and laser'd them, and they were happy at 375* give or take, all four even. So as long as I'm keeping the system happy and my bank account happy, I'm not drag racing it to worry about the heavy rotors. Plenty of other things make it heavy. The weight is good, it keeps temps down compared to smaller masses and rotors.
I'll probably have them turned after the next few hundred miles/event of tracking, if I can find someplace that will promise me very lightly lathing, nothing deep.
Pads look awesome, good thing considering they cost over $400 and I only drove them for a week! Nothing untoward indicating bad wear from rotors. Rotors same, nice.
I used my temp gauge on them after one cool down lap, jumped out and laser'd them, and they were happy at 375* give or take, all four even. So as long as I'm keeping the system happy and my bank account happy, I'm not drag racing it to worry about the heavy rotors. Plenty of other things make it heavy. The weight is good, it keeps temps down compared to smaller masses and rotors.
I'll probably have them turned after the next few hundred miles/event of tracking, if I can find someplace that will promise me very lightly lathing, nothing deep.
Last edited by journeymansteve; Sep 27, 2010 at 08:13 PM.
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^One reason to suspect that they are BETTER than the Standard, even as good as the Premium, is that they probably don't really cost what we pay for them. The US govt has had Yantai Winhere Auto-Part Manufacturing Co under investigation for dumping non OEM replacement rotors into the US market since 2007. I'm hoping they're importing and subsidizing nicer iron. Seems that most products, I hear Centric even, are mfr in China. So what the hell, it's worth a shot for me ....
^One reason to suspect that they are BETTER than the Standard, even as good as the Premium, is that they probably don't really cost what we pay for them. The US govt has had Yantai Winhere Auto-Part Manufacturing Co under investigation for dumping non OEM replacement rotors into the US market since 2007. I'm hoping they're importing and subsidizing nicer iron. Seems that most products, I hear Centric even, are mfr in China. So what the hell, it's worth a shot for me ....
The dumping thing is a good question. Based on what I have learned I would guess something like this.
Winhere see's a new p/n and makes a tool to produce it. It is very likely they also re-box their rotors for other brands. Honda rotors at $4-5 each -well you better make a lot of them. After time they realize the rotors won't sell at some rate that makes sense for that type of part - high volume -so they lower the price to make it move. This leads to the dumping fee that is added to the invoice of whomever imports the part.
Moving on - how to tell where the shortcuts are from 'standards' to 'premiums' - they are numerous. I'm not saying it matters - just ID'ing what it is.
The coating is obvious - a great feature but ultimately not important functionally.
Material specs are also important - but we can't see them. Of course China SAYS they are G3000 but melted scrap can vary significantly. If you've seen a giant magnet pick up scrap for melting - well it;s not hard to see that other junk gets stuck in there.
Every Chinese rotor I have seen is double disc ground sans some BPI rotors (AIMCO, NAPA, Raybestos brands). Every OEM rotor I have seen is not nor are 'premium brands' such as Brembo, DBA etc. They are fine turned. I don't know why precisely - but if it was a better process we would assume that the OEM would embrace it. I've never been able to find real data on that but that si a 100% 'cheaper' process. Kudo's if they have taken cost out with no sacrifice in quality or performance - but that is never easy to do.
What I do deem important in a rotor is the vane design and plate thickness. This is what you can see. Tip a rotor on it's side and look in - you will see what I refer to.
The vanes on OEM rotors are split in the center for core draft - this makes the vane section like an hourglass rather than angled in one direction. Very hard to describe in words but you can see it if you look. The result though - is the connection to the friction plates differs from side to side and thus heat transfer from the plates to the vanes is not even. I also see thicker plates on one side - again adding to uneven heat handling properties. It's impossible for me to quantify this - but at some point it makes a difference. Enough that the OEM will not make rotors like that.
In practice on track - which is what concerns me mostly I am split on what to tell people. I have had a few hard track guys use the Centric standards w/ poor results. They switched to premiums or went DBA or something. In particular the EVO rotor in Centric standard seems to be prone to early (not good) and sudden (really not good) failure. Is this BECAUSE those materials and details matter - or because EVO's eat brakes. Well I dunno. Both I would say. Perhaps in the case where the car is going to heat soak the rotors at 1500 degrees it simply does not matter a lot. I know the DBA 4000 lasts longer - but at the price it has to last a LOT longer to make sense. They are useful in Corvette world because a C5 may require rotor changes EACH DAY. That is no fun.
The Subaru Legacy GT Centric standard is quite the opposite. In this case - and I think volume plays a HUGE role - the rotor is 'better'. It has the proper split vanes and visibly is a better made rotor. The price does not really reflect that - I assume for Centric it comes out in the wash. So - one Centric rotor may be sourced and made quite differently than another. I know the boxes on both standards and premiums vary a lot in color and construction - and they should as they source the parts from different makers. You only see it when you have a stack.
Point being...I think there are fewer foundries in China than we think there are - and they work together to some extent to OWN the US rotor market. I'll make this one - you make that one etc. And it's definitely CUTTHROAT business.
We deem this business not even worth it - and gave it to China - which now seems like a poor choice as I expect a lot of un/under employed people would covet a good job in a production environment.
A bit of political ranting mixed in there - no SALES BS - and some reasonable data. I hope you find the lengthy post worthwhile.
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The dumping thing is a good question. Based on what I have learned I would guess something like this.
Winhere see's a new p/n and makes a tool to produce it. It is very likely they also re-box their rotors for other brands. Honda rotors at $4-5 each -well you better make a lot of them. After time they realize the rotors won't sell at some rate that makes sense for that type of part - high volume -so they lower the price to make it move. This leads to the dumping fee that is added to the invoice of whomever imports the part.
Moving on - how to tell where the shortcuts are from 'standards' to 'premiums' - they are numerous. I'm not saying it matters - just ID'ing what it is.
The coating is obvious - a great feature but ultimately not important functionally.
Material specs are also important - but we can't see them. Of course China SAYS they are G3000 but melted scrap can vary significantly. If you've seen a giant magnet pick up scrap for melting - well it;s not hard to see that other junk gets stuck in there.
Every Chinese rotor I have seen is double disc ground sans some BPI rotors (AIMCO, NAPA, Raybestos brands). Every OEM rotor I have seen is not nor are 'premium brands' such as Brembo, DBA etc. They are fine turned. I don't know why precisely - but if it was a better process we would assume that the OEM would embrace it. I've never been able to find real data on that but that si a 100% 'cheaper' process. Kudo's if they have taken cost out with no sacrifice in quality or performance - but that is never easy to do.
What I do deem important in a rotor is the vane design and plate thickness. This is what you can see. Tip a rotor on it's side and look in - you will see what I refer to.
The vanes on OEM rotors are split in the center for core draft - this makes the vane section like an hourglass rather than angled in one direction. Very hard to describe in words but you can see it if you look. The result though - is the connection to the friction plates differs from side to side and thus heat transfer from the plates to the vanes is not even. I also see thicker plates on one side - again adding to uneven heat handling properties. It's impossible for me to quantify this - but at some point it makes a difference. Enough that the OEM will not make rotors like that.
In practice on track - which is what concerns me mostly I am split on what to tell people. I have had a few hard track guys use the Centric standards w/ poor results. They switched to premiums or went DBA or something. In particular the EVO rotor in Centric standard seems to be prone to early (not good) and sudden (really not good) failure. Is this BECAUSE those materials and details matter - or because EVO's eat brakes. Well I dunno. Both I would say. Perhaps in the case where the car is going to heat soak the rotors at 1500 degrees it simply does not matter a lot. I know the DBA 4000 lasts longer - but at the price it has to last a LOT longer to make sense. They are useful in Corvette world because a C5 may require rotor changes EACH DAY. That is no fun.
The Subaru Legacy GT Centric standard is quite the opposite. In this case - and I think volume plays a HUGE role - the rotor is 'better'. It has the proper split vanes and visibly is a better made rotor. The price does not really reflect that - I assume for Centric it comes out in the wash. So - one Centric rotor may be sourced and made quite differently than another. I know the boxes on both standards and premiums vary a lot in color and construction - and they should as they source the parts from different makers. You only see it when you have a stack.
Point being...I think there are fewer foundries in China than we think there are - and they work together to some extent to OWN the US rotor market. I'll make this one - you make that one etc. And it's definitely CUTTHROAT business.
We deem this business not even worth it - and gave it to China - which now seems like a poor choice as I expect a lot of un/under employed people would covet a good job in a production environment.
A bit of political ranting mixed in there - no SALES BS - and some reasonable data. I hope you find the lengthy post worthwhile.
Winhere see's a new p/n and makes a tool to produce it. It is very likely they also re-box their rotors for other brands. Honda rotors at $4-5 each -well you better make a lot of them. After time they realize the rotors won't sell at some rate that makes sense for that type of part - high volume -so they lower the price to make it move. This leads to the dumping fee that is added to the invoice of whomever imports the part.
Moving on - how to tell where the shortcuts are from 'standards' to 'premiums' - they are numerous. I'm not saying it matters - just ID'ing what it is.
The coating is obvious - a great feature but ultimately not important functionally.
Material specs are also important - but we can't see them. Of course China SAYS they are G3000 but melted scrap can vary significantly. If you've seen a giant magnet pick up scrap for melting - well it;s not hard to see that other junk gets stuck in there.
Every Chinese rotor I have seen is double disc ground sans some BPI rotors (AIMCO, NAPA, Raybestos brands). Every OEM rotor I have seen is not nor are 'premium brands' such as Brembo, DBA etc. They are fine turned. I don't know why precisely - but if it was a better process we would assume that the OEM would embrace it. I've never been able to find real data on that but that si a 100% 'cheaper' process. Kudo's if they have taken cost out with no sacrifice in quality or performance - but that is never easy to do.
What I do deem important in a rotor is the vane design and plate thickness. This is what you can see. Tip a rotor on it's side and look in - you will see what I refer to.
The vanes on OEM rotors are split in the center for core draft - this makes the vane section like an hourglass rather than angled in one direction. Very hard to describe in words but you can see it if you look. The result though - is the connection to the friction plates differs from side to side and thus heat transfer from the plates to the vanes is not even. I also see thicker plates on one side - again adding to uneven heat handling properties. It's impossible for me to quantify this - but at some point it makes a difference. Enough that the OEM will not make rotors like that.
In practice on track - which is what concerns me mostly I am split on what to tell people. I have had a few hard track guys use the Centric standards w/ poor results. They switched to premiums or went DBA or something. In particular the EVO rotor in Centric standard seems to be prone to early (not good) and sudden (really not good) failure. Is this BECAUSE those materials and details matter - or because EVO's eat brakes. Well I dunno. Both I would say. Perhaps in the case where the car is going to heat soak the rotors at 1500 degrees it simply does not matter a lot. I know the DBA 4000 lasts longer - but at the price it has to last a LOT longer to make sense. They are useful in Corvette world because a C5 may require rotor changes EACH DAY. That is no fun.
The Subaru Legacy GT Centric standard is quite the opposite. In this case - and I think volume plays a HUGE role - the rotor is 'better'. It has the proper split vanes and visibly is a better made rotor. The price does not really reflect that - I assume for Centric it comes out in the wash. So - one Centric rotor may be sourced and made quite differently than another. I know the boxes on both standards and premiums vary a lot in color and construction - and they should as they source the parts from different makers. You only see it when you have a stack.
Point being...I think there are fewer foundries in China than we think there are - and they work together to some extent to OWN the US rotor market. I'll make this one - you make that one etc. And it's definitely CUTTHROAT business.
We deem this business not even worth it - and gave it to China - which now seems like a poor choice as I expect a lot of un/under employed people would covet a good job in a production environment.
A bit of political ranting mixed in there - no SALES BS - and some reasonable data. I hope you find the lengthy post worthwhile.
Awesome, I agree, both for mfr and the political stuff. Being a ME and a gear head (my emphasis in grad school was materials science), I knew a gamble when I put the $ down. The first thing I did when I got them opened was inspect the inside vanes and compare to the Brembo OEM. Same. Same placement, same shape of the vanes, symmetrical thickness on back/front plates.
On the political and business side, before I purchased them, I researched Winhere. They're investing hard this year in better foundries and improved quality, so I know I'm "scraping the bottom" in terms of older tech, but probably worth keeping an eye on the companies products as they bring higher-end stuff to the US market, dumping-prices or no. Hard to get any real data on G3000, material toughness or hardness though, short of taking it to a materials lab and doing some destructive and hardness tests on the thing.
I too wish the US would consider its need to protect itself from sole sourcing, especially when dealing with China. We don't seem to get on either party in the US for investing in banks and leaving our steel/iron industries on their own to "rust" while we import more and more of this.
I sorta wish I could measure the hot temp on the rotors -- even a quick cool down lap brought them down SO much, I know I'm not reading peak temps. Any suggestions for a thermal strip product and placement that I could use?
I have used some paint before w/ pretty good results. It comes in 250 degree increments - I'd get 750/1000/1250 or something like that.
If you are hard on the brakes they will get well over 1000 deg F on an EVO - rotor and pad wear really accelerates somewhere around 1500 degress I would think. A Nascar engineer said they like them at around 1000 for optimal performance/wear. The short track and road course stuff they have is quite impressive.
http://www.tempil.com/closeup.asp?cid=25&pid=27&theme=0
If you are hard on the brakes they will get well over 1000 deg F on an EVO - rotor and pad wear really accelerates somewhere around 1500 degress I would think. A Nascar engineer said they like them at around 1000 for optimal performance/wear. The short track and road course stuff they have is quite impressive.
http://www.tempil.com/closeup.asp?cid=25&pid=27&theme=0
Last edited by EVOBrakes; Sep 28, 2010 at 07:26 AM.
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EVOBrakes, thanks for the very informative post. I picked up my DS2500 pads from you but haven't installed them yet. From what I gathered, the Legacy Premium rotors are better than the Evo premiums. Would you recommend the Evo Centric Premiums for occasional track use and autox with the DS2500's? I don't think I need rotors just yet, but probably will soon. If I can feel a groove on the very outmost edge of the rotor (from wear), do I need to have the rotors turned or replaced? Or is thickness all that matters? Thanks!
journeymansteve, thanks for all the information on the Winheres too! Nice to hear that you checked out the vanes etc. Also, do you happen to have part numbers? I don't see them listed on rockauto under 2008 gsr.
journeymansteve, thanks for all the information on the Winheres too! Nice to hear that you checked out the vanes etc. Also, do you happen to have part numbers? I don't see them listed on rockauto under 2008 gsr.
Last edited by LaXGSR; Sep 28, 2010 at 08:46 AM.
LaXGSR
The centric standards for the LGT had vane design more like the premium's. In your case - I think you should get the premium's. The price difference is not too bad so I think they are worth it to get a more consistent product. They will last longer if they are heat cycled on the car before you track use them - that is one benefit of something like DBA. They are a less 'mass produced' casting so they are cooled better and heat treated.
Look at the pics called split castings on this page.
http://www.centricparts.com/index.ph...d=51&Itemid=85
You can see how the 'better' rotor is tapered in both directions.
As far as when to replace - generally look at minimum thickness - and you need a way to measure not including the lip. Your rotor starts at 32mm thick - the service limit is 30 mm or 1 mm wear per side. By law that has to be 'written' on the rotor (or drum)
On track they will likely crack before they get to that though.
-Ken
The centric standards for the LGT had vane design more like the premium's. In your case - I think you should get the premium's. The price difference is not too bad so I think they are worth it to get a more consistent product. They will last longer if they are heat cycled on the car before you track use them - that is one benefit of something like DBA. They are a less 'mass produced' casting so they are cooled better and heat treated.
Look at the pics called split castings on this page.
http://www.centricparts.com/index.ph...d=51&Itemid=85
You can see how the 'better' rotor is tapered in both directions.
As far as when to replace - generally look at minimum thickness - and you need a way to measure not including the lip. Your rotor starts at 32mm thick - the service limit is 30 mm or 1 mm wear per side. By law that has to be 'written' on the rotor (or drum)
On track they will likely crack before they get to that though.
-Ken
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