Brake Questions

["N" <twobees@xxxxxxxxxxx>]

Paul PDumond21@domain.elided asks about turning or replacing rotors on his M3.

Paul, it depends on how worn your rotors are now.  Buy a micrometer &
measure them.  Compare to factory recommended specs.  Did you wear your pads
down to metal so they scored the rotors?  If so, replace.

I seldom replace my rotors, but usually go through 2 sets of pads before
turning.  I don't think I've ever turned a rotor twice.  Once & then
replace.  This applies to all of my cars including the MGB vintage racer.

If you use your M3 at the BMW CCA schools or in BMW Club Racing, you may
want to consider cryogenically treated rotors.  Check this site (I have no
interest, financial or otherwise, etc.) http://www.frozenrotors.com/.  I
know some guys who race Porsches who have had their rotors treated like this
& swear that they do indeed work better & last longer.  I can't personally
attest to that though.

Re. s/s hose.  They are a must for any kind of serious driving.  They don't
expand as rubber hoses do so your pedal response is much more direct.  There
are a number of good suppliers out there.  Check some of the BMW parts
suppliers or ads in Roundel if you're a BMW CCA member.

As for painting your calipers.  Any high-temp paint will do.  I did the
rotors on my MGB 3 years ago.  That's about 30,000 miles and 3 race weekends
ago.  Paint is still intact, just dirty.  Paint came from local hardware
store.

Norm Sippel
'73 3.0 CS
'66 MGB daily driver, occasional racer
'61 Alfa Sprint Veloce
'93 Saab 9000CS - soon for sale

------------------------------