Rotor Roundtable

[Jehu]

I'm thinking of getting these (http://cgi.ebay.com/ebaymotors/BMW-E34-540-Cross-Drilled-Slotted-Rotors-F-R-W-Pads_W0QQcmdZViewItemQQcategoryZ33564QQihZ006QQite mZ160043738422#ebayphotohosting) or at least buying from these guys as their shop is close by me.For what its worth i've been to their shop and seen the rotors in their original Brembo boxes by the hundreds.They can give them to me this way, slotted only or smooth. I am thinking of looking for a place in my area who can Cryo them (http://www.nitrofreeze.com/index.html).Anyone ever get their rotors Cryo'ed?I like the idea of drilled and slotted becasue i like the extra ventilation but have been told drilling encouraged cracking and wondered if Cryonic treatment might be the ticket for adding back durability to a crossdrilled rotor.

[Rigmaster]

There's no point in drilling or slotting rotors for a street car, even a fast n furious street car. :P

The holes drilled in the rotor remove mass, and surface area AND they are prone to cracking more than solid undrilled rotors. If you ever experience brake fade on the street, you have other problems that cross drilled rotors will not cure.



Bret

[Alexlind123]

Holes look cool behind your big wheels!!

[Jehu]

Well cryo still sounds like a neat idea if its not too expensive.The price is the same for the rotors regardless of the machining anyway.

[MBXB]

Try frozenrotors.com

[BillionPa]

im running Powerslot Frozen Rotors. they are brembo and balo rotors that have been slotted, balanced, heat treated, cryo treated, and cadmium plated.

very very nice. diversified cryogenics is within driving distance so i was able to go down there and talk to the guys.

if i were to get rotors with holes in them, they wouldnt be drilled but rather cast that way with a camphered edge, that plus cryo treatment would pretty much eliminate cracking. cross drilling does also lower the rotor mass, which is good for non track use as it lowers rotating weight, but under intense braking provides less heat absorption.

slotting however doesnt remove much metal, but gives much better rotor performance when wet, allowing water and gasses somewhere to go other than the outside of the pad. it also lets you know when the rotor is worn, as the slots wont be there anymore!

buybrakes.com sells frozen rotors for way cheap, and you can get pads as well. free shipping!!!!

[neil_004]

From the site:
"Deep cryogenic processing permanently refines the grain structure of metals at the atomic level. Carbon particles precipitate as carbides into a lattice structure and fill in the microscopic voids. This creates metallurgically improved and stabilized rotors that have a denser, smoother surface. As a result, you reduce heat and wear on brake rotors and pads."

Carbon? I thought most brake rotors were cast iron? With steel if you can get it up to a bright cherry red you will get grain growth and change the structure of the carbon in the metal. I suppose under normal use this really isn't a problem.

Anyone ever run one cryo rotor and one normal one?

[winfred]

i've not installed drilled rotor on one of my cars yet but i have gone slotted on my last 4 cars (would be 5 but i couldn't get a deal on them for my truck) and it does make a difference in feel for the better even in normal driving, and when you are assing it around it helps a good bit, for example, stock e30 brakes suck and i can almost fade them with normal driving, crappy pads makes them even worse, my car with power discs is tolalrable but i really notice the difference in customer cars on test drives


There's no point in drilling or slotting rotors for a street car, even a fast n furious street car. :P

The holes drilled in the rotor remove mass, and surface area AND they are prone to cracking more than solid undrilled rotors. If you ever experience brake fade on the street, you have other problems that cross drilled rotors will not cure.



Bret

[Vanguard]

I can't speak to cyrogenic treatment for brake rotors. But that seems way overblown for cost. www.rockauto.com carries the Ate star slotted rotors and zimmerman crossdrilled e34 rotors for under $60 a pair.

Rotors are supposed to be sacrificial so why bother with all the fancy stuff.

[neil_004]

http://en.wikipedia.org/wiki/Cryogenic_tempering

Wiki doesnt have much more on the process. After reading that I can understand why it is a good thing with steel.