Re: Brake Fade

[AWE16VR6@xxxxxxx]

<< 	>>  I'm guessing its not your brake fluid - but your pads that are
 at fault.
 	>>  I'm running Super Blue as are several hundred others on this
 list and I've
 	>>  never boiled the fluid and "I don't brake until I see God"
 (dat's a
 	>>  'Stommelism').  More likely you are exceeding the capability of
 the street
 	>>  pads.
 
 I'd have no trouble agreeing with you completely except for 2 things:
 
 	1.  My pedal feel will comeback (for a couple of laps) if I bleed
 the system between runs.
 
 	2.  Unless I bleed between runs, it takes a couple of days, then the
 pedal feel will come back on its own.
 
 I can't reconcile this behaviour with anything other than boiled fluid.  If
 its something else, I'd LOVE to know what it is (this is all driving me
 nuts).
 - -Al
  >>

It does sound like you're boiling the fluid.  The ATE Superblue is decent, but
you may want to try a more race specific kind like Motul or AP.  The Castol
SRF fluid is the best at handling heat, yet costs ~$70 per liter!
Someone mentioned a four piston upgrade for the BMWs (I'm not as well versed
with these vehicles, which is why I am here: to learn), which will go far in
enhancing brake stopping force and *also* heat control.  The pistons on all
the 4 pot calipers I know of are stainless steel and do a tremendous job at
reducing heat transfer to the fluid, one of the properties of stainless.
However, since the heat now stays in the pads and rotors, a good ducting
system, race pads, and properly tempered rotors are necessary.  Also avoid
cross drilled rotors with this setup.  
I drive a VW Corrado VR6 on the track, and the extreme front weight bias
(engine centerline is in *front* of the front axles!) was too much for the
stock single piston caliper design regardless of pad or fluid choice.  The
only solution I found was the Wilwood Dynalite II front caliper conversion,
along with Hawk Blue compound pads.  Heat transfer was minimized so much that
I could get away with using Castrol LMA fluid and still not fade, even at a
heavy braking course like Watkins Glen.  However, I did fracture a set of
Brembo cross drilled rotors after my first 3 day event with this
configuration.

Of course, trying a higher temp fluid first may be the more prudent and frugal
move.

BTW, congrats on a quality and mature discussion forum.  I hope to pick up
some valuable tips here.

Todd Sager
Air & Water Enterprises
Foreign Auto Service
Philadelphia

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