We see this routinely on DSM applications - heavy discs cause perfect trannies to grind. You want the disc to be as light as possible while retainging strength. Thats the main reson for carbon / carbon discs that Tilton and now RPS use on the multiplate clutches. Not to mention the heat advantages.
Harry
Formerly yellowzxtt
" If it doesn't make it faster, i don't care " Please visit www.ztuner.com to GO FASTER