is it possible to lighten a stock flywheel?

[1991 318is]

i have a 91 318is when it comes time for a new clutch i was planing on a lighten flywheel. can i get the stock one lightened and a machine shop? i have a bud that owns the shop so i can get it done for next to nothing if its possible, i did not as him yet. i just was wondering if its a possible thing to do or am i just thinking of dumb stuff that cant be done?

[ak96ss]

Anything is possible...  however, being that this is a dual-mass flywheel, most shops can't/won't do it. At least, that's been my experience.

[DaveM-sport]

It be so much easier putting in an M20 fly and clutch

You could get your friend to take lighten that one then by taking off the lip

[agreen]

so how much is a lightened flywheel for my 318is i really want one of these anyone got one or know he chepest place to get one

[1991 318is]

ok well what is the exact parts i need to do the clutch and flywheel swap from the m20? i here the clutch is a little bigger and better also. i wanted a little more clutch so this might be a good way to go. but how much lighter is that fly wheel? and what car is it in maybe i can get a used one and get it lightined?

[gearheadE30]

The clutch and flywheel out of a 6-cyl m20, the m20 starter gear, and a trowout bearing from the e21 323i euro car are all needed. iirc our flywheels weigh close to 30 lbs. The m20 is 12-14.

[1991 318is]

The clutch and flywheel out of a 6-cyl m20, the m20 starter gear, and a trowout bearing from the e21 323i euro car are all needed. iirc our flywheels weigh close to 30 lbs. The m20 is 12-14.

is that there weight stock? can i lighting one of them at the machine shop? and whats the best place to get this stuff in Canada?
and how much of a difference will this make? so far i have a header and full 2.25 exhaust. i just want a little more of the line.

[gearheadE30]

Yup, stock weights. Now that I think about it, the M20 may be closer to 15 lbs, but it can be machined down to about 9. It will give you significantly better acceleration in 1st and 2nd, with a little bit better in 3rd. All in all, a 9-lb wheel will probably take close to a second off the 0-60. This is just what I have heard from others though; I plan to do this mod soon.

[D. Clay]

One of the M42 threads:
http://www.m42club.com/forums/showthread.php?t=2135

[1991 318is]

well when it comes time for a new clutch i know what I'm doing.

[DaveM-sport]

You have to machine the lip off the M20 Flywheel to make it fit I think alright but machining it down to 9 pounds? Think that might be a little excessive. A JE racing Flywheel is around that weight and they are Aluminium. I'd be kinda worried an M20 flywheel lightened too much could break hence taking off your ankles.

If your M42 Clutch goes the only way forward is to get an M20 replacement:cool:

[Kedge]

Do all US cars definately come with dual mass flywheels as all the M42s i've come across in the UK have had single mass flywheels which you can take some weight off.

[D. Clay]

If not all US M42's come with dual mass flywheels the overwhelming majority seem to. Have never seen or heard of OEM US model w/o dual mass. Australian models seem to be single mass also.

[haledj]

apparently in the US if you don't have A/C you have a single mass flywheel, but I have never heard of any cars without A/C from the factory.

[91318isguy]

Hey guys... Dumb question but... You mean that most places won't re-surface our flywheel? Or they won't lighten it?