MFactory DCT SMFW (6 and 8 bolt)

doublespaces

Administrator
Oct 18, 2016
7,055
AZ
It was a long time coming but the @MFactory DCT SMFW has arrived!

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For those who have been tuned into the Group buy thread, you'd know there are two different versions of the flywheel being produced to accomodate the two different crankshaft bolt patterns, 6 and 8 bolt versions. If your vehicle production date is prior to February 2009(most Model Year 2009 cars and earlier), then you most likely have an 8 bolt crank. If your vehicle is produced after that, then you most likely have a 6 bolt pattern.

There is a known problem with misfires above the 650hp mark when using either of the OEM dual mass flywheels fitted on the N54 and N55, and therefore the solution is the S55 flywheel as it does not suffer from the chatter/harmonics issue that triggers the knock sensors. The main problem with this solution that a few people have encountered: the S55 flywheel only comes in a 6 bolt flavor. So this product from MFactory is really a life saver for the 8 bolt crank folks.

The price is another big plus for the MFactory flywheel. Coming in at $499, this is half the price I've seen the S55 flywheel selling for. Despite people saying it goes in the ~$500 range on ebay, I've not seen any at that price lately and the MFactory unit is new and also lighter.

Previous reports have the S55/M3/M4 DCT flywheel weighing 17.8 lbs, with the N54/N55/335is/135i flywheel weighing 28.5 lbs. Using my scale, the 6 bolt N55 DCT flywheel came in at 27.2 lbs meaning my scale might be about a pound light. The MFactory DCT SMFW weighed in at 15.8 lbs, so using rough math we could say it is about a pound lighter than the S55/M3/M4 flywheel and over 11 pounds lighter than the OEM dual mass.

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Here are some photos I took of them on the scales, and also side by side since very few people will have any reason to own all three of these at the same time. Both dual mass flywheels weigh the same, with the MFactory smfw being comparable to the S55/M3/M4 flywheel. This might even be an option for S55 folks looking to save a pound or so.
 

mnick

Lurker
Jan 11, 2018
23
Tampa
Serendipitous timing, thanks for the information, wasn't sure if Mfactory was going complete this. I've been experiencing a loud sound with 1st to 2nd shifts under load while turning... added poly diff bushings which seemed to have helped temporarily. Mechanic took engine out (after I cracked a piston) and inspected the flywheel, he told me it was broken...
 

boostE92d

Corporal
Jan 9, 2018
147
Houston TX
Serendipitous timing, thanks for the information, wasn't sure if Mfactory was going complete this. I've been experiencing a loud sound with 1st to 2nd shifts under load while turning... added poly diff bushings which seemed to have helped temporarily. Mechanic took engine out (after I cracked a piston) and inspected the flywheel, he told me it was broken...
So you were driving around with a broken flywheel?
 

mnick

Lurker
Jan 11, 2018
23
Tampa
Yeah apparently you can reduce flywheel weight by breaking pieces of it and still drive....

I should have more details from the mechanic, regarding what was broken. I'll let you know as soon as I know more.

Update: “One of the springs was broken”.
 
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Asbjorn

Corporal
Mar 10, 2018
230
While I love the S55 flywheel due to the faster revs, it has made me stop using D mode. Car vibrates/chatters if you load the drivetrain in 5/6/7th gear at low rpm, which is bound to happen in D mode. So Im running S or M mode all the time now. Please consider this in case you want to borrow your car to others or care about mpg.
 
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doublespaces

Administrator
Oct 18, 2016
7,055
AZ
While I love the S55 flywheel due to the faster revs, it has made me stop using D mode. Car vibrates/chatters if you load the drivetrain in 5/6/7th gear at low rpm, which is bound to happen in D mode. So Im running S or M mode all the time now. Please consider this in case you want to borrow your car to others or care about mpg.
Interesting, I haven't heard of this problem yet? It makes sense because the S55 flywheel is essentially a SMFW, but I have not heard any reports like this.
 

dyezak

Major
May 4, 2017
1,765
Plano TX
Excellent site. I need to finish reading the M3 flash and GWS thread though...
Agreed, this board supports the community perfectly in my opinion. Look into the advanced coding and tuning sections too. Some guys there are doing crazy things with custom coding, CIC work, etc. They even got servotronic from the M3 working on our cars. To me that means that the Z4 35is electronic power steering should be compatible...which means getting rid of the power steering pump, reservoir, lines, etc...freeing up some space and a little power and having full electric power steering. After I finish the M Dynamic Mode and MDrive work that is probably my next side project.
 
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