Can a dual mass eta flywheel be machine lightened?

[Jand3rson]

I was orginally going to put a lightened 325i flywheel in my eta when I get it, but it apparently won't work (lacks the trigger needed to start the car).

So can I take I dual-mass eta flywheel to a machine shop and have it lightened? I realize it still probably won't be as light as a 325i flywheel, but it wil be better than the stock weight.

I will most likely be able to get it done for free, so save the "why are you wasting money on an eta" remarks. :D

[Beej '86 325es]

I have a lightened single mass flywheel on my eta and I don't think it was a waste of money at all. Check Metric Mechanic out, they lighten all sorts of flywheels. If you're not ordering from them, I'm sure they would be able to tell you.

[Jand3rson]

How do you have a single mass flywheel on an eta? Doesn't the eta one have the little trigger that is needed to start the car?

[Beej '86 325es]

Yeah, mine's got the reference pin on it, I believe they switched to a dual mass flywheel in 6/86. Mine's a 2/86 production. I believe 6/86 was the transition time when they switched a lot of things in that area of the car.

[rs4pro3]

Ya there are two different eta flywheels, single and dual mass. Both have have the little pin. The single mass eta flywheel still isn't as light as the 325i flywheel.

[Jand3rson]

Ya there are two different eta flywheels, single and dual mass. Both have have the little pin. The single mass eta flywheel still isn't as light as the 325i flywheel.

But it's still lighter than the dual mass, and probably easier to lighten. I may have to try to find one of these.

[Beej '86 325es]

what's the difference between a single mass and dual mass anyway?

[skat 325is]

Just to make sure.....

I have an eta tranny in my 325 with a dual mass wheel, wiil i have any problems if i install a 325i wheel ?

[Jand3rson]

Just to make sure.....

I have an eta tranny in my 325 with a dual mass wheel, wiil i have any problems if i install a 325i wheel ?

If your 325 is an eta, you will not be able to install a 325i flywheel, the car will not start.

[LowR3V'in]

It's not really a duel mass because it's one solid piece, but....
Here it is..


Probably a good 30lbs. :o

[LowR3V'in]

I have a lightened single mass flywheel on my eta and I don't think it was a waste of money at all. Check Metric Mechanic out, they lighten all sorts of flywheels. If you're not ordering from them, I'm sure they would be able to tell you.

How much does it weigh now and what was the stock weight?

[OreoGaborio]

ok.... i'm sorry, but it has to be said, LowR3V'in.... i hate your sig pic.... that saying makes me want to punch every computer geek in the teeth & stomp on their junk... it reminds me of the kid i whaled in the face w/ my Jr. High Science book cuz he kept on saying to me "I'M STEALING YOUR BRAIN" :? and i'm not a violent person... for a reason. i'm a skinny bastard ;)

[rs4pro3]

Lowr3v'n That pictures lookes the the single mass eta flywheel.
The difference is on the single mass flywheel the clutch disk has the spring mechanism built into it which absorbs the jolt from mating the tranny speed to the engine speed.
Where as the Dual mass uses a solid disk but with the spring mechanism built into the flywheel.
the 325i flywheel lacks the pick up point for the speed and reference sensor that the eta requires to run. One could maybe machine a tab and weld it on the exact same spot but I'd just machine and eta flywheel, or do an e to i cam swap and switch the motronic and wiring to that off a 325i.

[Beej '86 325es]

I have a lightened single mass flywheel on my eta and I don't think it was a waste of money at all. Check Metric Mechanic out, they lighten all sorts of flywheels. If you're not ordering from them, I'm sure they would be able to tell you.

How much does it weigh now and what was the stock weight?

The stock single mass eta flywheel weighs 24 lbs. The lightened one I got from Metric Mechanic weighs 12.

[e30Matt]

Dual mass is two separate pieces that can rotate a few degrees independently of each other. This smooths out the power on/off transitions, as well as shifts and other aspects of daily driving.

At least I think that's right. :?