Re: Ate Powerdiscs & brake shuddering

[Fluhr <ejfluhr@austin.ibm.com>]

Gary Kaklikian writes:
>I now have G60's, Pagid orange racing pads, cryogenically-treated ATE power
>disks (5000 style), and a Girling dual master cylinder unit. This set up was
>working great at the track until the Road America event. At Road America,
>the brakes were working well. I was able to brake hard  into the turns,but
>once the brakes got hot (second lap), there was a bad shudder coming through
>the brake pedal (not the steering wheel), which consequently made me brake
>earlier than I wanted to, particularly at the end of the long straights.  On
>the street, this is hard to reproduce unless you do repeated hard braking
>from speed.

Gary,

This may be due to the pad you are using with the Powerdiscs.  I had
the same behavior with the Raybestos pads and Ate Powerdiscs at the
track on my Coupe GT.  My Hawk HPS pads do not exhibit the shuddering
feeling (same track, same day, back-to-back sessions).  I have also
encountered the problem on my urquattro with my KVR carbon fiber pads
on the street but not on the track.  I was doing several hard stops
without much driving time in between, and noticed it at the end.  The
same brake system did not shudder at the track, but it also gets
lots of cooling airflow at the time (unlike my street test).

I suspect it may be due to (1) gassing of the pads, or (2) the pads
biting so hard that they literally chew into the rotor as they pass
over the groove.  My suggestion is to try another pad or set of
rotors.

Later,
Eric
'85 CGT, '82 urq
---
Eric J. Fluhr                                Email:  ejfluhr@austin.ibm.com
High End Processor Design                    Phone:  (512) 838-7589
IBM Server Group                             Austin, TX