steve40th

Okay, there have been a few threads to say the least on rotors.
Well what makes the rotor so bad or good?
Who here knows the material needed to make these C5/C4 rotors last through HPDE type abuse??
Pads are pretty well thought out and there is an abundance of great pads.
But no onw talks of material to make the rotors great? I think this ought to be brought out. SUre Napas are cheap, probably cost a buck to make in the Chinese sweat shops, and a buck to ship them here.
But what about Brembo rotors, and the many other companies that make rotors.
Just curious.

Sidney004

From High Performance Brake Systems by James Walker jr.
" Cracking is typically attributed to the heat cycling of gray cast iron, but the details are sketchy at best. Even material scientists have a hard time explaining the exact reasoning for this failure! However, most agree that rapid heating and subsequent cooling of the rotor around 900 degrees F creates internal stresses in the gray cast iron matrix, which are then relied by the cracking of the material. Precise control of friction disk chemistry can be used to resist cracking in some applications, but cracking will occur, albeit at a reduced rate."

steve40th

I was reading where Wilwwod stated their rotors are made of "premium long grain carbon iron which helps provide long wearing rotors where high heat situations".

AU N EGL

900*F thats nothing . .



try 1400* to glow ORANGE


Brake rotors are iron. Best heat absorption metal.

brakes stop the car do to friction. Friction causes heat.

That heat has to go someplace, into the rotor.

focused

2000BSME

I guarantee that brake rotors would last longer (from a cracking standpoint) if materials like Chromium, Nickle, and Tungsten were more abundantly used in their construction, but then agian, the cost would probably be prohibitive.

Only reason I say 'gaurantee' is that I see furnace rolls operating in a constant temperature of 2200*F all day/night long, while supporting heavy slabs of cast steel (25 tons, about 60 ft long) at work every day. Nickle/Tungsten/Chromium has very good high strength under high temperature conditions properties. The materials might not be good from a wear standpoint though, it would be nice to see some experimentation with them.

vms4evr

I believe those guys from Racing Brake marketed the same thing on here. I also believe they have been chased off as their rotors crack just as nice as everyone else's.

So far the only rotors I'm aware of that actually take a beating are Coleman. Unfortunately you can't get a rotor for your stock calipers.

John Shiels

I ask them and they never responded.

John Shiels

What is the composition of a real high budget race teams rotors that are not CF? I guess we use them for 20 minutes 4-5 times a day and a race team uses them once and junks them without all the constant heat cycles up and down.

Sidney004

Every brake application and subsequent cooling down cycle that causes the rotor to exceed 900 F and cool off below that point will induce crack inducing stress on cast iron. At a place like Laguna Seca, that probably occurs four times a lap. If you were able (F1 style, though carbon-carbon) to manage the heat flow to keep the rotor temp always above 900 F during use would solve the problem or large enough rotors with mega cooling and pads designed to operate at lower temps so it would not exceed 900 F. I agree that different metallurgy would do the trick as well.

0Vector Vette

I have designed a 2 piece rotor and hat using Coleman rotors. I have been using them in TCC for 3 years now and several of my competitors are using them as well. I have them for the C4, C5, C6, C6 Z51, C6 Z06 and a 14 rotor with a AP racing 6 piston caliper. We are getting excellant wear form them. However, they aren't made in China and do cost more than those that are.

steve40th

Can you give a price range, C5 price?
And do you have C4 rears in 2 piece?

0Vector Vette

Stock size C5 fronts are $312 each. Replacement rings are $147 each.
They are directional. I have not done the rears yet as I have not had trouble with the stock ones. I do plan to make them as weight savings is an issue. On my new C6 racecar, I am using the AP racing 14" setup on the front, and the stock C6 front caliper on the rear with my 2 piece rotor. Let me know if I can be of assistance.
Robert Finlayson