I think ZF Sachs makes an upgraded clutch.
http://www.sachsperformance.com/Sach...4376_4587.html
Here is ZF Sachs contact info...
S-Performance GmbH
Elbring 45
21217 Seevetal
Phone: +49-(0)40-3999 211-8
Fax: +49-(0)40-3999 211-9
Email:
info@sachsperformance.com
I do not think Sachs has a US importer - yet.
Acording to
RealOEM.com the 1M and the N55 135i's use the same clutch disc...
# 21217598492
http://realoem.com/bmw/partxref.do?p...ur=&series=E82