Gents, I'm planning a big service on the car that includes forge-ing the engine. The question is: since I am changing the clutch should I go for a SMF? I've heard so many horror stories with SMF ... and I want to hear more oppinions! Is it worth the change performance wise? If it's just vibrations as cons, I could live with, if it's damaging gearbox in time... not!
Sounds like your car is broken with a SMF. If a shop is recommending one, they are absolutely clueless!
The SMF is nothing to do with damage to gearbox but more smoothness of engine as a DMF will absorb vibration and smooth interaction with clutch when you release the pedal, saying if a flywheel is well balance and of appropriate mass for the engine coupled with a dampened clutch disc then it should be ok