Quote:
Originally Posted by ace996
http://www.bimmerfest.com/forums/sho...7&postcount=16
Link above shows pretty bad taper and some bushings that are supposed to help this non-existant taper
Reduce what?...you just said there is no taper.
So what is it? Is there taper, like evey other slider experiences when used hard on a track or is there no taper and those solid bushings are just BS?
And what about pad size? The multi-piston calipers use pads that are larger..in contact patch...they're able to take more heat and will last longer..as they do in every other application.
???...WTF???? Your question?
|
all pads taper to a degree...but it's not a problem...it's normal...
they have to...the disc is rotating in one direction primarily...
although the area is larger, that means little
especially if the mean radius of the centroid of their area is smaller...
Ff = u N
you see area in that equation?
what this means for a constant rate of decleration (brake torque)
the pressure on the rotor is the same (all else being constant)
it's the material that matters, not the area...
a larger pad may wear less, but not stop better or heat less...
what is more important is the size (mass and surface area) of the disc
most of the heat goes into the disc, NOT the pads...it's ENGINEERED that way...you could stop a train with a large enough disc and a properly designed 1 sq in pad and touch the pad when done, it would only be warm...
Q = -kA(dT/dx)
take a look at the relative difference of the pads areas...
as you can see heat conduction is linear with the area, NOT squared...
so a small difference in area means nothing if the material is suitable...
this is all about bling...otherwise they would not epoxy coat the calipers...