shaving a flywheel

[rcfanatic]

What should I specify to have the flywheel reduced to 12-13lb? The flywheel thickness is already at 32mm (and it weighs 20lb now), so I don't see a way of removing any material from the clutch side, and the machinist I'm working with estimated that you could only remove about 3-4 lb from the crank side.

Any advice is greatly appreciated, as this car is my DD and my only vehicle, so I would like to get it on the road again asap. Thanks!

[rcfanatic]

Anybody know what the significance of the flange is? Maybe a wear indicator?

[rcfanatic]

I'm about to have this done too.

I'm wondering if anyone has an idea of what the step is for on the clutch side of the fw. I measured it this morning and it's only .010" which seems basically negligible compared to the overall thickness of the flywheel. Does this .010" really make a difference and why?

Also, should I remove the 3 dowel pins from the fw before taking it to the machinist, or will they do this?


thanks,

[Wh33lhop]

The crank does not need balancing. However, if you've got the pressure plate that you're going to use you could have him balance it with that (I did).

Here's the back of my shaved flywheel:



You could have taken some more off.

[ACHTUNG]

As a reference... I just did this when I swapped in a 5spd. Photos:

Looks like you could have taken more off that.

[erik325i]

I asked my machinist about doing this and he was more than willing but required the crank so that he could balance them together. From what I've been reading this is not necessary............... Any ideas?

The crank should already be balanced, so as long as he balances the flywheel, it should work.

Erik

[E30Gus]

I asked my machinist about doing this and he was more than willing but required the crank so that he could balance them together. From what I've been reading this is not necessary............... Any ideas?

[95///M3]

As a reference... I just did this when I swapped in a 5spd. Photos:

[lennon]

Glad you're happy... I know I was when I had it shaved!

hahaha

[sweetride01]

Glad you're happy... I know I was when I had it shaved!
I still gotta do the Z3 shifter though.....

[aTron12]

Drove my car around today after having the new clutch/shaved flywheel installed. The machinist shaved it down to 14LBS. He didn't feel comfortable taking it any further. I gotta say it made a really noticeable difference. The throttle response is much smoother and takes less effort to get those R3V's up. No issues with idle at all.. like not even a slight change. Drives the way a BMW should! We also installed a Z3 1.9 shifter which is a really nice addition to the experience. Slides right into gear perfectly and has a really nice tightness & quicker throw. Thanks for the advice...

[KenC]

Fine for the M42. I have a 13lb 323 flywheel in mine.

[ecalder]

Anyone know if you can still shave the flywheel the same for an m42 with the m20 clutch/flywheel swap? I'm replacing my tranny on the m42 and thought I might as well go through with the swap... and if I'm doing the swap why not go ahead and shave it down too? Anyone have an extra one laying around btw?

[sweetride01]

Nice... I still haven't got around to putting in a short shift kit...

[aTron12]

Great guys. Thanks a lot! I'll get back when the job is done next week. I'm replacing the clutch, shaving the flywheel and putting in a z3 1.9 shifter.

Adam