I'm trying to determine what aftermarket clutches could be installed in the 1M.
Mine is fine, but given its track use, I'm planning ahead.
I haven't yet checked parts numbers, but my understanding is that our clutch is same as the 335is (and, perhaps, the Z4 version) except that we have a lighter flywheel.
And, I believe that our tranny is the same as the one installed in the 135i.
Would appreciate any information about the differences between our 1M and other N54-motored models that might affect which clutches could be installed.