Brake pad materials - ratings/selection

[JayMaechtlen]

Sorry, my Google-fu is filing me today.
I thought there were some ratings for brake pads, in terms of temperature resistance/behavior, effectiveness /grip hot versus cold.
Most of the "info" I can find is subjective and/or inconsistent.

help?




Jay Maechtlen

http://www.laserpubs.com/techcomm

 

[swall]

Jay, I worked in the automotive brake industry and I do not recall any standardized ratings. The friction material manufacturers offer a variety of compounds and the fitness for any specific application must be determined by testing. The friction material manufacturer would be offer some guidelines to get one started and narrow down the selection process prior to testing.

 

[JayMaechtlen]

Ok. thanks.
When doing a conversion, how do you figure out what material to start with?
(for example, using a standard assembly in a different vehicle)

thanks
Jay

Jay Maechtlen

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[patprimmer]

Brake pad selection really is a compromise and to me co-efficient of friction is the least of the issues, except to maybe balance out front to backs.

If the pads are low friction, with modern boosted (over boosted) systems it's still relatively easy to press hard enough to lock wheels.

A lot depends on what you are prepared to compromise for what, ie Noise/squeal, black dust on rims, fade, life, rotor wear, cold vs hot performance.

Personally I always looked for fade resistance and better hot performance over everything else, then reasonably quiet, but then I'm a bit of a lunatic when I find a nice quiet winding road or mountain pass. I also tend to tow heavy loads at times.

I still prefer sintered copper/ceramic pads with the knowledge they may squeal a little and will need a warm up, ie left foot brake and drive slow from a cold start for the first 100 yards or so.

Regards
Pat
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[MintJulep]

Energy per stop per unit area of pad is a good starting point.

If the duty is quite different then you need to consider energy over time as well.

 

[JayMaechtlen]

Oh, well - for this project, I need smaller wheel cylinders up front, and grippier pads in the rear.
Eventually, I should probably go with disks up front instead of the ancient drums.

Yes, this is the bastard Corvair I've asked about in the past- rear MacPherson struts, 3.8 Buick, etc.



Jay Maechtlen

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[patprimmer]

Maybe you need an adjustable proportioning valve, although I do think get it as good as you can, then leave less for the valve to do.

I guess your using the drive train out of a front wheel drive V6, installed in the rear, brakes and all.

Regards
Pat
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[GregLocock]

In all the modelling of brakes I've ever done, mu has been 0.4

I'm not saying it doesn't vary, I'm not saying nobody makes a 0.6 pad. But we don't fit them. Change your mechanical or hydraulic advantage.



Cheers

Greg Locock


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[patprimmer]

Wheel and tyre size can also have an influence, but they should be chosen for other reasons so it is a bit of a side effect.

Regards
Pat
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[JayMaechtlen]

Thanks for the info and advice.
Jay

Jay Maechtlen

http://www.laserpubs.com/techcomm