Page 1 of 1

Rotor Choice

Posted: August 7th, 2009, 9:43 pm
by Hoodzy
http://cgi.ebay.ca/1996-Mazda-MX3-Preci ... 286.c0.m14
First I was wondering if anyone has used these? Think I should get them.
I have OEM one's and warped the crap outta them
Wondering if anyone had any other suggestions.
I would like ones which have a protective coating so they dont get all rusty and gross.
THanks

Re: Rotor Choice

Posted: August 7th, 2009, 9:54 pm
by RS_OBD'oh_2
Check out KVR. IIRC they are in Canada and are of good quality. Keep in mind that the coatings will probably wear off after some use. At least the slots or holes should remain rust free.

Re: Rotor Choice

Posted: August 7th, 2009, 10:34 pm
by Inodoro Pereyra
I agree with RS_OBD'oh_2: don't get hung up on coatings. They don't last.

About the holes, keep in mind that cross drilled rotors have a tendency to develop cracks over time, especially starting at the innermost holes, so you have to keep an eye on them.
Other than that, cross drilled rotors should give you good braking with no fade, and they should not warp. And they definitely look good too... 8)

Now, if you're not in it for the looks, a solution that has given me good results in racing for years is to buy slotted rotors, and drill a hole on the outer end of each slot, so the slot itself will do the degassing without weakening the rotor's structure.

Hope it helps... :)

Re: Rotor Choice

Posted: August 7th, 2009, 11:58 pm
by RS_OBD'oh_2
Inodoro Pereyra wrote:Now, if you're not in it for the looks, a solution that has given me good results in racing for years is to buy slotted rotors, and drill a hole on the outer end of each slot, so the slot itself will do the degassing without weakening the rotor's structure.
Whoa, that's kinda cool. Do you have to resurface them after the drilling?

Re: Rotor Choice

Posted: August 8th, 2009, 12:56 am
by Inodoro Pereyra
RS_OBD'oh_2 wrote:
Inodoro Pereyra wrote:Now, if you're not in it for the looks, a solution that has given me good results in racing for years is to buy slotted rotors, and drill a hole on the outer end of each slot, so the slot itself will do the degassing without weakening the rotor's structure.
Whoa, that's kinda cool. Do you have to resurface them after the drilling?
No. You can do it 2 different ways, depending on how you're gonna use them. If you're not gonna demand too much of them (let's say, you're gonna use them for oval racing, or time attack), you make the hole smaller than the width of the slot, so any burr will stay at the bottom of it, not reaching the surface (which doesn't mean you can't deburr them if you want to), or if you're gonna beat the heck out of them (let's say, running 40 or 50 laps on a road circuit, where you have to break hard 10 or more times a minute for about an hour), you do the hole as big or slightly bigger than the slot width, and then with a diamond bit you round up the edge , making sure to get rid of any burrs, both inside and outside the slot.

Re: Rotor Choice

Posted: August 8th, 2009, 2:16 am
by fowljesse
You know alot about rotors :)
Maybe you know what rotors the guy used that were about 2" larger O.D. and I think they were 6 lug. He had them drilled for 4 lug, but were otherwise bolt-on. You would have to drill a new hole, and move the calipers.

Re: Rotor Choice

Posted: August 8th, 2009, 6:38 am
by Inodoro Pereyra
fowljesse wrote:You know alot about rotors :)
Maybe you know what rotors the guy used that were about 2" larger O.D. and I think they were 6 lug. He had them drilled for 4 lug, but were otherwise bolt-on. You would have to drill a new hole, and move the calipers.
Not really... Believe it or not, the 2 posts above are about all I know on the subject... :oops:
As far as I know, the "hole in the slot" was my idea (I've never seen anybody using that before), but it came to be almost by accident.
When I was a teenager, I started seeing some people using slotted and cross drilled rotors, supposedly to improve braking, and one of my first reactions was to ask "how do they expect to improve braking if they're taking away braking surface from the rotor with all those holes?". Yeah, I knew THAT much about it...
Then, when I started getting involved in racing, years later, I started using slotted rotors, and making 3 holes on each slot, to "save braking surface, while lightening the rotor", which I thought was the reason for the holes. Later on, I met a mechanic who taught me the real reason for them, and laziness (drilling rotors is a PITA) is what caused me to go from 3, to 2, to 1 hole per slot.

About your question, I don't know, but there aren't many 6 lug rotors around. I don't know if it'd be worth it though, being that you have to drill 2 new holes in the rotor (and you have to be VERY precise), besides modifying the caliper brackets...

However, if I were to take the time to adapt rotors from another car, I'd definitely go with the Porsche carbon fiber rotors and 6 piston calipers. You wouldn't believe how light those things are... 8)

Re: Rotor Choice

Posted: August 8th, 2009, 3:46 pm
by Mooneggs
That's an interesting idea about drilling a hole at the end of the slot... :confused2:

If your application is daily driving/spirited daily driving I suggest blanks and some decent pads.
If your application is autocross/more aggressive driving I suggest slotted or slotted/dimpled and some performance pads.

I don't think I will ever use cross drilled ever again... IMO they are for looks only (at least on the mx-3).

Re: Rotor Choice

Posted: August 9th, 2009, 1:23 pm
by Nd4SpdSe
I've used 2 sets of slotted and cross-drilled and never had them warp or crack on me. Used ceramic pads.

Re: Rotor Choice

Posted: August 9th, 2009, 2:02 pm
by Hoodzy
what brand?

Re: Rotor Choice

Posted: August 10th, 2009, 12:49 am
by Nd4SpdSe
They were Brembo blanks drilled and slotted by this guy on eBay
http://myworld.ebay.com/sportbrakes_int" onclick="window.open(this.href);return false;
Which it seems he doesn't have anything at all.

Re: Rotor Choice

Posted: August 14th, 2009, 9:13 pm
by Towona
I just bought rotors from this seller:

http://stores.shop.ebay.ca/PowerOne-Aut ... it=Search

Havn't installed em yet, but they look quite decent.... especially for the price.