<brakes> Re: Helium cooled rotors, weird pad wear

[Jim Walsh <jimw@xxxxxxxxxxxxx>]

I have a set of rotors I've had cryo-treated waiting for me to pick up from
the shop.  So no experience yet.  I'll find out soon, I think cost is about
$15 a rotor, fair number of the local Porsche track drivers have it done,
supposedly doubles rotor life, so worth it just from that perspective (let
alone the pain of swapping rotors yourself vs. just doing pads).  BMW rotors
are even softer than Porsche, so I think it'll work well.

BTW, car is a '91 E34 M5, not exactly 100% stock.  On my third set of rotors
in the year I've owned the car, maybe this'll drop me to one set a season
:-)

On an only mildly related note, I had some very weird pad wear at my last
track event - the left rear pads wore down to the backing plate, but all
other pads (I'd replaced them all 2 weeks earlier) were totally fine - like
1/4 worn.  They were stock pads (as the shop 'accidentally' sold my Pagids
to someone else).  Anyways, I swapped out the pads, and the piston wasn't
stuck and no other strangeness in the caliper, and it can't be the parking
brake since that operates the right rear.  Since the local track (SIR) is
counter-clockwise, it would be easily explained if the car has traction
control, which is so is certainly an interesting 'hidden' feature, but I
can't think of any other explanation.  Both pads as well, so it's not like
one of the pads had the pad compound break up and fall off.  Have driven the
same track many many times before and never saw this behavior before, so I'm
befuddled.

Jim

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