From: Marc Thomas [mmthomas@ix.netcom.com]
Sent: Saturday, August 19, 2000 5:41 PM
To: 928
Subject: [928] Big Reds

Folks,
First, there is a difference in "drilled" rotors.....there are drilled hole
rotors, and there are cast hole rotors.  The difference is
significant....most racing orgs will not allow drilled rotors, but will
allow cast hole rotors!  This is for a reason.  In the casting process,
material grain forms around the holes, whereas in the drilled process, the
hold interrupts the grain, thus creating a stress concentrator!

Don't be fooled by salesman jibber.....a cast hole will show surface
cracking, just as a normal rotor under hard use, and a drilled rotor will
show deep cracks...possible through the side of the rotor!

If the cast rotor is correctly cast, then the chamfer goes below the minimum
rotor thickness level.

There are slotted rotors, they are great also, however, the do not have the
heat shedding capacity of a "holed" rotor, but share a similar gas/fluid
(water) shedding capability..again, not a s good as a "holed" rotor.

All rotors should be ground to provide the correct surface finish...I forgot
the location of the correct surface finish, but it is in factory lit
somewhere...

The combo of big brakes and correct rotors/pads is incredible, just ask Don
H or Kim C...both of themt have driven cars equipped with our big brake
kits.....Kim C comments are in our catalog...




Warmest Regards,

-- 
Marc M. Thomas
DEVEK
650-592-5287 phone
650-610-0557 fax
http://www.devek.net