Time for a new clutch for my e36 m3, a flywheel question...

So the clutch on my e36 track day car is on its way out.

I am looking at several different kits and am leaning towards one manufactured bt Sachs.

The question is should I go with a 10.5 lb aluminum flywheel or the 14.5 steel one.  Both are significantly lighter than the stock 23lb dual mass that is in the car.

I have heard a lighter flywheel will cause transmission noise from gear lash on these cars?  Does anyone have any experience with this?  Tell me about your setup.

Car is used for track days, autocross and is occasionally driven on the weekends.

UUC E34 M5 clutch and lightweight flywheel.  Been on the car for years, I've used this setup in two different cars.  Works well, flywheel does make noise but not obnoxiously so.

The UUC flywheel doesn't have the greatest reputation on the forums, but I've never had an issue with it?

In reply to docwyte :

How much does the uuc flywheel weigh?  Why a e34 m5 clutch vs a e36 m3 one?  Is the flywheel an e36 m3 application or an e34 m5?

DMFs are hamonic dampers at the other end of the crank.   Given that the M3 engines were known for eating themselves if you eliminated the damper at the front, I'd be leery of eliminating the one at the back.

And yes, transmissions seem to get more unhappy when you replace a DMF with a solid flywheel.  More of the engine harmonics get transmitted right through to the gears, which may have only been sufficiently engineered if they were protected by the DMF...

DMFs are fiddly and expensive but they do serve a purpose.

Don't worry about the gear rattle.  It won't make an ounce of difference to the transmission.  As to the choice of flywheel, buy quality.  I put a cheesy aftermarket one in my Neon IT car and it had cracks in the bolt circle within a year.

I've put tens of thousands of miles with lightened, single mass flywheels on my E36 M3 without a single issue.  Don't worry about it....

I switched from a dual mass to an aluminum flywheel on a c4 vette (zf transmission also used in the 8 series) and couldn't have been happier (the rattle at idle sounded bad but was harmless)

Don't forget however the move may bump you in a class at autocross.

What about 14.5 lb vs 10.5 lbs?

If others haven't had issues, go to it then.  I've noticed that CTS-V transmissions get really unhappy when you remove the DMF, and that's with a V8.  I've noticed a similar effect on VWAG 1.8ts.

Personally, when talking SMFs, I don't think one can ever go too light.  But driver technique plays a role, too.  If you expect to be able to engage the clutch without meeting it with throttle, you're going to have a bad time.