Brake rotor Freezing
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Originally Posted by dss
Has anyone heard of the process of freezing the rotors to improve the flow characteristics of the metal, thus enabling the rotors to last twice as long?
Premium Supporting Vendor
Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
I've heard of it and many swear by it. For me, at $25 a pop for stock rotors, I decided it wasn't worth it. Might be for other uses than the track though...
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AMSOIL Preferred Customer Program (Members buy at Wholesale - a savings of about 25%)
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
My wife's Grand Cherokee warps rotors like its it's job. I got a cryo'ed front pair from frozenrotors.com for ~$100 each. They have held up longer than any of the other rotors I have tried. I have noticed a bit of a thumping again recently but I'm not sure if it's the front or the rears doing it.
Unless you have a problem like the '99+ Jeep Grand Cherokee's though I can't see the need, especially when NAPA has them for ~$25 as mentioned above. C5's aren't really known for going through rotors, unless they are autocrossed.
Unless you have a problem like the '99+ Jeep Grand Cherokee's though I can't see the need, especially when NAPA has them for ~$25 as mentioned above. C5's aren't really known for going through rotors, unless they are autocrossed.
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,817
From: Charlotte, NC (formerly Endicott, NY)
Autocrossing doesn't do anything to the rotors although running race pads at a track event will. Agree that the $25 rotors are cheap enough to consider expendable but the labor of changing them at the track isn't something you want to spend your time doing. Cryo treatement can be done for as little as $25 per rotor so at just double the price it might be worth it to get a couple more days use out of a set of rotors.
Bill
Bill
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
We have seen a few guys with them at DE school on the track. Those rotors cracked as fast as D/S rotors all with in a day. Both corvettes and porsche guys. 
Raybestos at $25 per rotor are the longest lasting track rotor
To help brakes last longer, cooling ducts are the best advice.
Raybestos at $25 per rotor are the longest lasting track rotor
To help brakes last longer, cooling ducts are the best advice.
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Burning Brakes
Joined: Dec 2004
Posts: 1,234
Likes: 2
From: New Jersey
I heard (edit: know presumes first hand knowledge) of at least 2 major tier 1 brake suppliers that researched Cryo and found that when using liquid nitrogen and the rotors are in contact with the gas that it does harden the surface of the rotor.
But, and it's a big but it makes the rotor more brittle..permanently. Brittle at the surface, which causes cracks and flaking.
Another drawback is that it also reduced the coefficient of friction of that surface.
Which means on a brake rotor you will decrease your brake torque.
The only papers out there I could find on the subject where all written by companies offering cryo treated components. Not the most independent group.
Now I'm not completely read up, but I suspect that the nitrogen has more to do with the hardness than the cold.
There is a well known and proven metal treatment called Nitriding, which is basically enriching the surface of a metal using nitrogen to increase it's surface hardness and improve wear characteristics.
I say suspect, because traditional gas nitriding is done at higher temps not lower. And the nitrogen usually comes from the decomposition of ammonia gas. So, I'm just thinking out loud.
FYI:
Definition of Nitriding:
But, and it's a big but it makes the rotor more brittle..permanently. Brittle at the surface, which causes cracks and flaking.
Another drawback is that it also reduced the coefficient of friction of that surface.
Which means on a brake rotor you will decrease your brake torque.
The only papers out there I could find on the subject where all written by companies offering cryo treated components. Not the most independent group.
Now I'm not completely read up, but I suspect that the nitrogen has more to do with the hardness than the cold.
There is a well known and proven metal treatment called Nitriding, which is basically enriching the surface of a metal using nitrogen to increase it's surface hardness and improve wear characteristics.
I say suspect, because traditional gas nitriding is done at higher temps not lower. And the nitrogen usually comes from the decomposition of ammonia gas. So, I'm just thinking out loud.
FYI:
Definition of Nitriding:
Nitriding is a surface-hardening heat treatment that introduces nitrogen into the surface of steel at a temperature range (500 to 550°C or 930 to 1020°F), while it is in the ferrite condition. Thus, nitriding is similar to carburizing in that surface composition is altered, but different in that nitrogen is added into ferrite instead of austenite.
Because nitriding does not involve heating into the austenite phase field and a subsequent quench to form martensite, nitriding can be accomplished with a minimum of distortion and with excellent dimensional control.
Because nitriding does not involve heating into the austenite phase field and a subsequent quench to form martensite, nitriding can be accomplished with a minimum of distortion and with excellent dimensional control.
Last edited by Mighty-Mouse; Jan 24, 2005 at 04:44 PM.
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
Yes Mighty Mouse you are correct. Liquid Nitrogen does cause the item that is dipped into it to become brittle. Very Very brittle. After that item as been restored to room or abient temp that item is subject to what is called freeze/thaw burns i.e. creats bigger gaps in that material.
The other problem is that the cold of liquid nitorgen only penitrates a few millimeters as bubbls form around the item. the rest of the item takes hours to cool down if at all.
Even it the a secondary liquid is use ( isopentate ) or submerssed in a vessel that is surrounded by Liquid Nitorgen and the Item is dipped into the almost frozen liquid isopentane to -273* C ( not absolute Zero )
Yes I have work with Liquid Nitrogen for 15 years. and I have also read many articals and non have convinced me. I would love to talk to a metalurgest who is NOT employed by one of these companies to get an unbiases information
So I am also very very sceptical of the process, but open to understand new ideas.
The other problem is that the cold of liquid nitorgen only penitrates a few millimeters as bubbls form around the item. the rest of the item takes hours to cool down if at all.
Even it the a secondary liquid is use ( isopentate ) or submerssed in a vessel that is surrounded by Liquid Nitorgen and the Item is dipped into the almost frozen liquid isopentane to -273* C ( not absolute Zero )
Yes I have work with Liquid Nitrogen for 15 years. and I have also read many articals and non have convinced me. I would love to talk to a metalurgest who is NOT employed by one of these companies to get an unbiases information
So I am also very very sceptical of the process, but open to understand new ideas.
Burning Brakes
Joined: Dec 1999
Posts: 1,121
Likes: 0
From: Atlanta GA
About 2 years ago I took a set of factory rotors and had them frozen. I forget who I had do it. They held up fine but I went to Baer rotors because they look cooler!
Then I sold the Baers because I'm cheap and but a set of regular factory rotors on and I've warped them. Argh!
Then I sold the Baers because I'm cheap and but a set of regular factory rotors on and I've warped them. Argh!
