ceramic or semi-metallic

[Kyle65mustang]

Hey guys, I just bought a pair of 03 cobra calipers to put on my 65 mustang. The calipers come with semi-metallic pads in them (new). I want to autocross this car so my question is: should I leave them in because they work better before coming up to temp or go ceramic? Thanks for any and all help

[Apogee]

If only it were so simple...but it's not. Just because a pad is marketed as "ceramic" or "semi-metallic", that doesn't really tell the whole story as to the actual performance characteristics of the pad. A good example of this would be several friction suppliers (Carbotech, Satisfied, etc) for which all of their pads are technically "ceramic", meaning they have more than a minimum percentage of ceramic ingredients that would allow them to call the pad compound "ceramic". These manufacturers make compounds that vary from normal street use to full-on race use, many of which have 40+ ingredients in varying quantities to get the desired performance characteristics.

My suggestion would be that you run the semi-metallics that came preloaded with your calipers...sometimes those are decent pads and other times they not, but you won't know until you run them. As for new pad recommendations, that would really require more information about your particular setup (manual versus power, street versus track, RWHP, tires, weights, etc).

Tobin
KORE3

[CarlC]

As usual, words of wisdom by Tobin.

[gio75camaro]

Tobin had some excellent points also where you run into problems is operating temperature of each pad ( semi vs. ceramic ). And then you also have to worry about pad wear.

Simple answer, choose something that's comfortable a fits what YOU are gonna do with the car.

[iadr]

Check the posts from "barefoot":
http://www.turbobricks.com/forums/showpost.php?p=1094278&postcount=8

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http://forums.turbobricks.com/showthread.php?t=49643

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http://www.turbobricks.com/forums/showthread.php?t=40636

[72BBSwinger]

IMO the best stopping pads will make a lot of dust and will also be noisy. But in the stopping dept they are killer.

[iadr]

IMO the best stopping pads will make a lot of dust and will also be noisy. But in the stopping dept they are killer.

If I can summarize the links I posted above, that is mainly because on "pure street" pads, the rotors are polished, and infact a slick deposit is purposely built up, for long life (and I suppose low noise, etc).
On a race pad, and even many high dusting European cars, the rotor is kept "cut" down to elemental iron/carbon of the cast iron.
In fact the rotor is sacrificed in use. As he points out, the black-rust colour on Mercedes wheels can be as much the dust from the rotors being ground up as the pad dust.

The "grip" rating of the pad (how much "whoa" for a given psi of line pressure and disc diameter) is called mu
You can do a Google on brake bad mu and be entertained all night.
There is actually an official system for rating mu. Unfortunately it's not a very finely graded system and most common "performance street" pads end up all being rated with the letters FF...some high end ones are one up from that...G or H...and I don't believe most of the race pads are advertised with their ratings given in that system.

[72BBSwinger]

I run Hawk HP+ at the track and some oe pads everywhere else. I do this knowing that the Hawks don't like the others "film" left on the rotors so I clean the rotors real good when I go to the Hawk pads.

[MonzaRacer]

For OEM replacement Ceramics dust less and are usually quieter. Semi Met will dust more and be little noisier.
AS for aftermarket performance pads those rules may not apply.
Now in clutch pucks ceramic metallic is better for high horse power usage but wears flywheels and is less daily driver friendly.