Single vs Dual Mass Flywheel

[IceyVert]

I just picked up my manual swap. It is a late ETA with the dual mass flywheel. Previous owner said he originally had single mass and swapped back due to chatter and sold the single mass. My question is if it is worth it to buy a single mass and have it lightened to 14/15lbs? He said he saw no difference in performance but that’s hard to imagine being this flywheel is 28.5lbs. My plans for the car are just ported head/cam/headers nothing major. Wondering if I should save the money or go ahead and get the single mass? Sent from my iPhone using Tapatalk

[e30davie]

Hows the condition of the dual mass? i've only seen one and it was stuffed, im no expert but i assume the two parts are supposed to move quite smoothly but also be quite difficult to move, not flopping around.

I personally chose to not use the dual mass (i never did drive on it), and got a single mass. Mainly as i didn't want to take the gearbox out again if the dual mass flywheel gave up (i assume that is possible) and the dual mass seemed incredibly heavy. Depends what you can find, i got a single mass for 50 bucks but that was a few years ago now. Surely lighter has to be better:)

[IceyVert]

It was inspected and in good order. $50!? I can’t find them for less than $275!!! Sent from my iPhone using Tapatalk

[EuroChriz]

It was inspected and in good order. $50!? I can’t find them for less than $275!!! Sent from my iPhone using Tapatalk

Drop a link please, I need to order one too asap for a swap

[e30davie]

50bucks was a second handy oem one that i had to get resurfaced...

You might as well buy a fancy light weight one for that price.

https://racehead.com.au/product/bmw-light-flywheel-m20/

[EuroChriz]

50bucks was a second handy oem one that i had to get resurfaced...

You might as well buy a fancy light weight one for that price.

https://racehead.com.au/product/bmw-light-flywheel-m20/

I have a E30 track car already haha, this is for the stock weekend e30. Plan to drive it up to Vintage in 2 weeks

[e30davie]

oh in that case, chuck the dual mass in and forget about it:D

[m3clutch]

someone more knowledgeable has to chime in, and I won't search myself because lazy, but, can't having too light a flywheel mass throw off the way the m20 runs? Depends on mods, but too light a wheel might not provide enough soak for engine at idle or at speed? Not sure if this is true or not...maybe I will search.

[IceyVert]

someone more knowledgeable has to chime in, and I won't search myself because lazy, but, can't having too light a flywheel mass throw off the way the m20 runs? Depends on mods, but too light a wheel might not provide enough soak for engine at idle or at speed? Not sure if this is true or not...maybe I will search.

True, but I’m not trying to put in something like an 8lb aluminum, just a stock single mass. Sent from my iPhone using Tapatalk

[EuroChriz]

oh in that case, chuck the dual mass in and forget about it:D

I've got a duel mass from a 86 325e laying around but need to put it in a 89 325is

[jbontke]

Was the clutch stock that the previous owner used stock?

The early 325e did not have a twin mass flywheel. Then some where in '86 BMW started using them. In the 325i (starting in '87), BMW used single mass flywheel. I have read of people switching to the single mass flywheels on the 2.7 engine. I would like to know what single mass flywheel the previous owner used, OEM or another unit? I would say the OEM single mass flywheel would be best for OEM like driving characteristics (assuming a sprung hun clutch disc).

[IceyVert]

Was the clutch stock that the previous owner used stock? The early 325e did not have a twin mass flywheel. Then some where in '86 BMW started using them. In the 325i (starting in '87), BMW used single mass flywheel. I have read of people switching to the single mass flywheels on the 2.7 engine. I would like to know what single mass flywheel the previous owner used, OEM or another unit? I would say the OEM single mass flywheel would be best for OEM like driving characteristics (assuming a sprung hun clutch disc).

Yea, stock clutch. His car was a 325i he swapped it into not an E car. Sent from my iPhone using Tapatalk

[TobyB]

Chatter sounds like a friction disc/ surface problem.

The dual mass does give that nice buttery- smooth idle and an easy low- rev launch,
but like Davie, I never found it hard to locate a single- mass flywheel.
so I've always used those.

For street use, the only difference is that it takes a bit harder stab at the throttle
when rev- matching. It's not gonna affect your 0-60 or lap times enough to get
out of the noise floor.

t
analog