[Shotimes] Porterfield R4S Observation/Question

[Ron Porter]

Ran a set of Porterfield R4S in the 598 pad size for the '96 brakes on my
'94 MTX at Blackhawk. Pads and rotors were new a couple of days before the
Convention. Pads worked great! I had solid brakes all the way through each
session, and the rotor temps after the 2nd session were 630 front, 550 rear
(car has the bias plugs) which was fine.

After the track session the rotors have the usual coating of pad deposits,
which always wear off in due time. By the time I got home, I noticed that
the LF rotor was getting chewed, and the brakes were noisy. I assumed the
pads were shot, but this was the first time the upper outer surface was
getting chewed.....it has always been the inner side in the past.

Anyway, pulled the parts to install some new pads & fresh rotors. To my
great surprise, all four of the front pads were only half-worn, and were in
very good shape!! Their mating surfaces are even smooth, and not grooved. It
appears that, under very-hard-use conditions, the R4S pads chew up the
rotors. The upper part of the outer LF rotor had it, as well as the lower
part of the inner RF rotor. It almost seems like the pads use the material
deposited on the rotor as a grinding compound!

Those rotors are turnable, the pads can be reused, and overall I'm happy
with the R4S, but the situation seemed a bit strange. Anyone else see this
with these pads?

Ron Porter