Racing Rotors

crzyone · Post by **crzyone** » Sat Feb 02, 2008 2:44 pm

A friend from work used to work in Ontario at a carbon fiber business. They made specialty CF parts for race cars like splitters, wings and other structural parts.

He brought one of the rotors they used to make for the Lola racing cars they built parts for. Here are some pics.

The rotor has a graphite core with pressed carbon fiber as the friction surface. These are super light and huge.

Wear indicators. This rotor was only on for a short test run so there is plenty of life left.

I asked him if he could get more of them so I can have one (hopefully 4 of them). :afrocool:

whipped · Post by **whipped** » Sat Feb 02, 2008 3:21 pm

I bet there's nothing like having to worry if your brakes are going to shatter on a hard stop.

Aaron · Post by **Aaron** » Sat Feb 02, 2008 4:15 pm

And it is a good indication that your car needs a diet if you are still overheating your brakes when they are as big as your wheel is.

Kohburn · Post by **Kohburn** » Tue Feb 05, 2008 12:09 pm

what pad material do you use with those? and how is the heat discipation through pressed graphite?

i'd be worried about the rotor wearing away instead of the pad.

crzyone · Post by **crzyone** » Wed Feb 06, 2008 12:52 am

Don't know anything about the pads, but it would make sense if they were carbon as well. I don't think you would want something too abrasive.

These are for high end race cars, I imagine they have to be fairly durable during a race.

The Dark Side of Will · Wed Feb 06, 2008 12:55 am

I believe pads of the same construction are used. Both the rotors and the pads wear heavily and require replacement during a race (at least during an enduro).

Chase Race · Post by **Chase Race** » Wed Feb 06, 2008 2:31 am

Kohburn wrote:i'd be worried about the rotor wearing away instead of the pad.

You're probably right and that's probably why they have wear indicators built into the rotor surface.

Kohburn · Post by **Kohburn** » Wed Feb 06, 2008 9:45 am

great for a race where things get completely replaced and rebuilt before the next race. but in no way practical for street

crzyone · Post by **crzyone** » Wed Feb 06, 2008 2:14 pm

Road grime would kill these quickly.

I can't imagine how heavy these would be if they were iron, even with an aluminum hat.

p8ntman442 · Post by **p8ntman442** » Wed Feb 06, 2008 8:12 pm

I wonder why they dont do 380si aluminum rotors like the cyl walls in my proto block. The aluminum would disperse the heat so well, they would last forever, and they would weigh nothing. The down side would be that you would have to run iron pads, which would probably make a lot of noise.

whipped · Post by **whipped** » Wed Feb 06, 2008 11:01 pm

http://www.freepatentsonline.com/5407035.html

Blue Shift · Post by **Blue Shift** » Thu Feb 07, 2008 4:51 am

p8ntman442 wrote:I wonder why they dont do 380si aluminum rotors like the cyl walls in my proto block. The aluminum would disperse the heat so well, they would last forever, and they would weigh nothing. The down side would be that you would have to run iron pads, which would probably make a lot of noise.

Probably warp the shit out of them. Also aluminum starts getting sticky really quick. On top of that, I thiiink brake rotor temperature can exceed the actual melting point of aluminum if you're getting on them enough?

The Dark Side of Will · Thu Feb 07, 2008 7:50 am

Yeah, aluminum has a low specific heat and a low melting temp... both are bad properties for a brake rotor.

p8ntman442 · Post by **p8ntman442** » Thu Feb 07, 2008 10:04 pm

yet they work for cylinder bores? I call bullshit.

p8ntman442 · Post by **p8ntman442** » Thu Feb 07, 2008 10:06 pm

whipped wrote:http://www.freepatentsonline.com/5407035.html

No the aluminum is an alloy containing silicone. Acid etching eats the aluminum away to improve hardness.

The Dark Side of Will · Thu Feb 07, 2008 10:17 pm

p8ntman442 wrote:yet they work for cylinder bores? I call bullshit.

Cylinder bores have a water cooling jacket and are lubricated by oil. The aluminum only survives because of measures taken to reduce friction.

Bake rotors have neither cooling jackets nor lubication. Their operation depends on large amounts of friction.

Aluminum is a lousy brake rotor material.

The Dark Side of Will · Thu Feb 07, 2008 10:22 pm

Wilwood does make aluminum rotors for specific racing applications:

http://www.wilwood.com/Products/002-Rot ... /index.asp
http://www.wilwood.com/Products/002-Rot ... /index.asp

Series8217 · Post by **Series8217** » Thu Feb 07, 2008 11:50 pm

This is very cool:
http://www.imp.mtu.edu/information/brake_rotor.htm
Aluminum rotor with bonded steel friction surfaces. They claim the cost for making them is comparable to standard rotors.... but I certainly have seen them in production, so I don't know what come of it.

Standard · Post by **Standard** » Fri Feb 08, 2008 12:49 am

whipped wrote:I bet there's nothing like having to worry if your brakes are going to shatter on a hard stop.

It always seems like there's at least 1 or 2 Rolex DP cars that have their rotors blow up during an endurance race...

IIRC, one of the DP cars at this years 24 hours of Daytona had a rotor blow and almost take the driver out.