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I bought some rotors off ebay from V12 Motorsports. I chose them because there was a thread recommending them and they're inexpensive. They are drilled and slotted but you can order them just drilled or slotted or blanks since they are machined after you buy them. I chose only slotted because anything other than blanks adds brake wear and drilled rotors can crack occasionally. The seller is excellent to deal with, although the rotors do take a few days to machine the holes and slots.

I have some concerns with the rotors though. The slots have a very small lip around them that you can just barely see. If you run your finger nail across the slot, you'll feel it hit the lip. I was worried that this might cause brake wear and after a few days my wheels had lots of brake dust on them. Next, the rotors have directional cooling vanes so there should be a left and a right so airflow is goes in the right direction. All the rotors they sell have directional vanes designed for a right wheel. I emailed them and got this response:

"We understand exactly what you mean regarding both rotors vanes being tilted same direction- we have a few more front sets ready for today's shipments. The performance comes from drilled/slotted, the internal vanes will be cool (much cooler than OE blank) regardless of both vanes in same direction. Everything will be OK, trust us =)"

I remember reading one time that over 90% of cooling on drilled and slotted rotors comes from the vanes. Everything else about them is decent quality. Do you guys think the directional cooling vanes going the wrong way is a problem?
 

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I bought some rotors off ebay from V12 Motorsports. I chose them because there was a thread recommending them and they're inexpensive. They are drilled and slotted but you can order them just drilled or slotted or blanks since they are machined after you buy them. I chose only slotted because anything other than blanks adds brake wear and drilled rotors can crack occasionally. The seller is excellent to deal with, although the rotors do take a few days to machine the holes and slots.

I have some concerns with the rotors though. The slots have a very small lip around them that you can just barely see. If you run your finger nail across the slot, you'll feel it hit the lip. I was worried that this might cause brake wear and after a few days my wheels had lots of brake dust on them. Next, the rotors have directional cooling vanes so there should be a left and a right so airflow is goes in the right direction. All the rotors they sell have directional vanes designed for a right wheel. I emailed them and got this response:

"We understand exactly what you mean regarding both rotors vanes being tilted same direction- we have a few more front sets ready for today's shipments. The performance comes from drilled/slotted, the internal vanes will be cool (much cooler than OE blank) regardless of both vanes in same direction. Everything will be OK, trust us =)"

I remember reading one time that over 90% of cooling on drilled and slotted rotors comes from the vanes. Everything else about them is decent quality. Do you guys think the directional cooling vanes going the wrong way is a problem?
Personally, if they didnt tell about the directional issue on the auction, i would tell them to either send me a correct left and right set, or refund my entire purchase amount including shipping and send me a return box. i think it would look kind of wierd having one side of the car with rotor vanes running opposite from the other side.

as far as performance, i do agree a bit with them that cooling shouldnt really be affected, but i have also heard there is an issue of getting debris trapped in there if they are not running the correct direction.

as far as the lip goes, thats just a bad cut job. my guess would be it will get removed after a few turns between your pads, but if there answer is "it will be okay, trust us", that would leave me a little irritated.
 

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Discussion Starter #3
i think it would look kind of wierd having one side of the car with rotor vanes running opposite from the other side.
You can't really see the rotor vanes that easily. Just to clarify, by vanes I mean the strips of metal sandwiched inside the rotor. The slots that you can see are machined with a left and a right so that they appear the same on your wheel. I have about 15% pad left and have new ones so hopefully the rest of this pad will smooth out the ridges around the slots so they don't wreck my new pads.
 

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My understanding is about slotted/drilled and brake rotors in general is: the slots and drilled rotors have nothing to do with cooling. They simply help exspell the gas built up during braking reducing brake fade and the brake pad floating over the rotor after the build up of gasses. Cooling comes from the vanes, rotor thickness and diameter. Think of it as a radiator, the more surface area the better the cooling.

I've seen the slots go in both directions, either way they go they still perform the same job.
 

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My understanding is about slotted/drilled and brake rotors in general is: the slots and drilled rotors have nothing to do with cooling. They simply help exspell the gas built up during braking reducing brake fade and the brake pad floating over the rotor after the build up of gasses. Cooling comes from the vanes, rotor thickness and diameter. Think of it as a radiator, the more surface area the better the cooling.

I've seen the slots go in both directions, either way they go they still perform the same job.
:agree The slots supposedly help keep the pads clean also.
 

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I've heard of drilled rotors cracking between the holes, making slotted only better. The drilled/slots do get rid of gasses, but do cool the rotor some, how much depends on if you are performance driving. Normal street duty shoulnd't be a problem. I worked at a place that sold AC Delco slot/drill rotors and they said that theirs are better than the Chinese ones sold elsewhere on Ebay. I have ran ebay rotors on 4 cars and haven't had any problems with them. But, if your's arent' chamferred, and not directional, I may be skepticle of the quality and seller.
 
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