shaving a flywheel

[sweetride01]

That is helpful. So maybe I will stay at 15lbs in hopes of finding a good balance between performance and stability. I am running a stock cam...

Yea, I'm sure 14-15 lbs should work just fine for you...

[Wh33lhop]

Why stop at 15? Mine's at about 12-13lbs, I've noticed zero decrease in drivability.

[erik325i]

If you're going to have it machined, take it down to 12-13. It would be silly to stop at 14-15.

[aTron12]

Why stop at 15? Mine's at about 12-13lbs, I've noticed zero decrease in drivability.

So, you are running a stock clutch etc, had your flywheel shaved down to 12-13lbs and no negative effects at all? Your idle is fine?

Just being thorough here because I want to do it right the first time!

[sweetride01]

As I mentioned, I think ~12lbs is fine with a stock cam, it's only when you start doing other things that mess with the idle that you're likely to start running into problems.

[Wh33lhop]

So, you are running a stock clutch etc, had your flywheel shaved down to 12-13lbs and no negative effects at all? Your idle is fine?

Just being thorough here because I want to do it right the first time!

I'm running a stock M50NV with a shaved-down flywheel, bathroom scale said it was 13lbs IIRC. No driveability issues at all, and it idles sort of funny but that's probably because I don't have an O2 sensor hooked up yet. ;)

Honestly, I'd rather have a lightweight flywheel with a lumpy idle and a cam than a regular-weight flywheel. You may be able to adjust your idle speed as well, depending on how you're tuning it.

[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

[sweetride01]

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

[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?

[KenC]

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

[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...

[sweetride01]

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

[lennon]

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

hahaha

[95///M3]

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

[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?