carbon brakes from steel

Ok i am changing the brakes as soon as they get here maybe tuesday next week
I have never had them before and will not have time to test before we go next weekend
any hints, advice to running with carbon brakes
what needs to be done before we run
help please...

 

carbon brakes

Talk to Manzo. He knew it was coming, and has it all figured out. WOW go figure !!Talked to him @ E-Town. about it. It,s not that big of a deal. Break clean, and maintance.

 

It has been my understanding to never use Brake-Clean on Carbon Fiber rotors or pads as they will absorb it and decrease the braking ability. When I clean off the calipers and floater hubs, I use brake clean on a rag and stay away from the carbon. They do seem to not grip as well as steel when stopping from the burnout but it has been a long time since I had all steels to do a comparison. Other than that, they act pretty normal and stop the car great.

Tom

 

Remember on the carbon brakes you need to ride the brake in your burn out..get them hot, when they get hot they stop real good..Dave

 

False. Mythbuster's should do a show on it. They stop good hot, but they also stop good right out of the staging lanes.

Drive them like you drove with steel brakes. The only difference you'll see besides how good they work is carbon dust in the wheels. The harder you ride them the more they dust. Blow the wheels out with a blow nozzle and you're good to go.

 

Thanks Randy
You can’t believe what all I have heard about carbon brakes
I was gung ho to put them on 6 months ago and a person talked me out of it.
I went into the sand in May, no chutes, on a pathetic pass but still doing 210 mph
I was amazed at how bad the brakes started to fade right up to the point when I heard the belly pans sliding across the pea gravel, not sure what mix they use at Norwalk but it works, you cant hardly walk in it, 6K later in body work and we are good to go.

 

Randy thanks for the heads up..talking to strange about them and that is what they told me to do..the desk person or a racer??? racer...thanks Dave

 

I will second that too!!!

I can't tell you how many stories i have heard about the brakes , BUT Randy's post clears some of it.

Randy can you describe some mantenience?? is it true about the brake cleaner? Baking them?

thanks in advance
JP

 

maybe the pm is different as its heavier but i have had full carbon brakes for 2 1/2 years now and no way will they hold a tight airgap in stage unless you warmed them in the burn out,
and also if i dont ride the brake in the burnout, when im of the power and braking i end up past the 1/8 mile lights they simply wont stop well when cold,
iv tried this both ways as rotor /pad wear is prety bad when you ride the brake every time and there not cheap,
Top end is a different story they hot up so quick i doubt the braking efficiancy is affected by not being warmed, iv had a few chute faliers and never hit the mud, yeah no sand trap here we have a field...

Interesting post Randy id like to see a myth busters on this subject done too

Graham

 

I think the quality of your Master Cyl has a LOT to with how well your brakes work, sttl or carbon!

 

Several facts about carbon brakes:
Although surface area is equal to steel, however having two like compounds applying brake pressure WILL improve stopping power.
All mounting and centering practices are as important in each brake application as is M/C sizing (these items are VERY important).
Keeping pistons retracted is also very important as the volume increases as the pads and rotors wear and pistons are allowed to travel out in the caliper bore, this is simple to address just by shimming.
Carbon will withstand much higher heat without fading so heat shields and proper fluid will enhance their performance.
Use NO brake cleaner or introduce to ANY chemical contaminates, if so they MUST be baked to burn off such contaminates (this material is VERY porous, and can easily be embedded deep int the surface.
When pad and rotor surfaces become glazed they should be re-finished, this can be done as simply as scuffing with paper (being careful as to not distort surfaces).
Kurt-Prostart Race Cars

 

John,

I noticed on RJ that you had your old hubs and rotors for sale and they are Mark Williams so your new one will be the same as mine. After really standing on the brakes on a late chute, no chute or short track situation, the brakes will stop you no problem. The only issue I have when hot is that I get a loud clicking noise from the rear brakes where the pads have to be grabbing the rotors and letting go. It sounds like I’ve lost a couple of teeth in the rear. I called Mark Williams after it started and they knew of the issue but did not have a fix for it. It goes away as soon as they cool down and I have had no problems because of it, just annoying. Anyone else run into this?

Tom

 

Deflnatly have this all the time
Its caused by the fact that MW rotors are full floating and as they move about the washers that retain the rotor on the hub become bent and allow far more movement than normal the noise is your rotors moving about and the pads grabbing on the rotors as you move around due to the heat, When they cool they no longer grab at the rotor,
do you use residual presure valves?
just so you know steel rotors wont fit where carbon rotors were without changing the hub and vise versa (Mark Williams)

 

I'll have to look at the washers closer, thanks. Yes, there is a 2 LB valve in the the rear circuit.

 

Assume for a minute a person has a properly designed front/rear steel brake system already, with the proper proportioning valve and pedal/lever ratios and the proper master cylinder.

If then a switch was made to front & rear carbon, would any of the other hardware or ratios above have to be changed?

In other words, if a retrofit to carbon is performed, what other changes should ideally be included (if any) at the same time? Thanks.

 

There should be no changes necessary provided that all of the other items are correct. The "new" 10" and 11" kits do have a different piston size in the calipers and may require a fine tuning to the system, but otherwise the same. Using 5.1 fluid is an enhancement just "NEVER" silicone fluid.
One more concern with the increase in front braking, the spindle to chassis attachment "a-frames" should be reviewed for tosional strength.
Kurt-Prostart Race Cars

 

Great Info

Kurt has hit the nail on the head, great info, but I'd like to add a simple refresher course from experience.
When it's right, it's right! Watching cockpit shots of Allen Johnson in P/S pumping his hand brake prior to staging, simply tells me he's got air in the lines.
When it's right, the first pump should be as good as the second. It's all about proper bleeding and a good working 2 lb. RPV.
If bleeding manually (not pressure), the very first thing to know is: go slow and gentle! One bubble can easily be turned into a thousand tiny ones if the stroke is done fast! You MUST have patience. No matter how hard you try, tomorrow will show that a few tiny bubbles gathered back into a big one, so plan for it on day 2.
I use a glass jar, 1/2 full of new fluid, and a clear plastic 1/4" o.d. hose squeezed over the bleeder after a 1/4" BOX wrench (spanner)(I hate open end wrenches), once the hose is filled, you can visually see if you have air.
I know it's anal, but I like to sleep really well!

Bob

Meyer Race Cars / San Diego
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