Dual mass flywheel balancing

[rob76turbo]

Originally Posted by bmwm750

Eh, plenty of us are running light flywheels, I love mine. Some would argue that you should only run a LWF if it is balanced to the engine, and on a track car I would agree. What is critical, is that you change the rigid clutch disc for a sprung unit.

You should also be able to retrofit the 3.8 engine's harmonic balancer to the pulley side of the motor to further smooth things out.

How do you balance the LWFW to the engine? I am thinking of going this route, but will be doing the R&R myself (along with IMS, RMS, trany mounts, ETC).

[jaykay]

Just curious as to whether anybody knows whether a light fly wheel could mitigate crankshaft and RMS damage by reducing the overhung weight at the back of the crankshaft. I would think the DMFW at 40 lbs, slightly unbalanced, on a slightly untrue crank could cause undue crank shaft deflection resulting in RMS damage and leaks. I would think by the time you have an RMS leak you already have engine damage.

I was thinking of a LWFW just to prevent this scenario but I am just learning about all the negatives associated with it. I have a very low mileage engine (m96) that I would like to make reliable.

What flywheel would I use to be safe? Do I need a clutch to go along with it? It is not a race car so I would like to keep it as streetable as possible. What are the risks? Will a dynamic balance problem be caused?

Thanks,

jaykay

[Cloudsurfer]

Unfortunately, to balance the flywheel to the rotating assembly the motor needs to be torn down, so that's only an option during an engine build.

Hypothetically, some argue that the use of a LWF will make the RMS seal more reliable. Others contend that the LWF has it's own set of downsides.

If it's a stock, street car, you can get a stock equivalent sprung centered clutch. Always use a new new pressure plate.

[BYprodriver]

Originally Posted by bmwm750

Unfortunately, to balance the flywheel to the rotating assembly the motor needs to be torn down, so that's only an option during an engine build.

Hypothetically, some argue that the use of a LWF will make the RMS seal more reliable. Others contend that the LWF has it's own set of downsides.

If it's a stock, street car, you can get a stock equivalent sprung centered clutch. Always use a new new pressure plate.

I would think the besy solution would be a lightweight aluminum pressure plate. I have never seen one advertised or even discussed. Anyone else heard anything??

[Jake Raby]

A LW pressure plate is being tested now with 3 different stages of aggressiveness.

[BYprodriver]

Nice to hear, I look forward to that!

[Cloudsurfer]

Now that sounds interesting...