M40 Flywheel swap - vibration?

[Jay-Vee]

...just realized I should have started a new thread instead of hijacking the other one... oops!


So I'm considering the M40 flywheel option and possibly getting it lightened, but I'm a bit concerned about the vibration it causes versus the small performance gains.

Would lightening the flywheel increase these vibrations? My project is leaning more toward restoration rather than for track purposes, but I did want to change the flywheel as one of the few modification to make it a bit zingier.

If it makes the engine feel/sound particularly harsh then I think i might stick with the stock Dual-Mass flywheel and retain the smoothness this gives.


Appreciate any opinions guys.

[1998ccc]

I have 2 M42 cars, one with the stock dual mass and one with the M40 flywheel.  The M40 fly is still heavy but ~5 lbs lighter than the dual mass.  You can definitely tell a difference driving them back to back.  THe M40 flywheel is dead quite...no gearbox rattle.

I would go to the trouble to lighten the M40 or go M20 if I had to do it again.

[johna]

As I said in the other thread I didn't notice much difference going from DMF to the M40 flywheel but other people have said that they have. The harshness I noticed was only at low engine speeds under load, like when you are taking of up a hill so not a big deal.

If you want maximum smoothness and comfort the factory knows best so stick with the DMF, but if you want to chase a bit of extra zippiness then worth trying a lightened M40 flywheel or maybe the one from RHD engineering.