Light single mass flywheel vs OEM DMF

[Rubes]

Just upgraded from OEM DMF (12,68kg) clutch kit to performance light SMF (7,2kg) clutch kit. It was a must after 85.000km under APR stage 1 (316HP & 516Nm).

Tested...and I love it! Numbering advantages wold take time, more of it in detail soon. For the time being, let me mention the only downside, literally: I need to rev engine just a little bit higher, in order to start smoothly. Let's say 1.200rpm - 1.500rpm.

Yes, somewhere outside town in quiet winter landscape discreet shatter can be heard:

1. From the outside in neutral.
2. Barely from the inside only when pressing gas pedal in neutral within 750rpm to 1.000 rpm range, beyond that and while in idle: nothing. In total.

I feel like I am driving another, much better car.

Looking forward hearing about your experience with OEM DMF vs after market Light SMF.

Edited 19 December, 2017 by Rubes
Smaller image

[Jaco2k]

Welcome to Briskoda!  There is a wealth of knowledge on these boards!

[Rubes]

Just now, Jaco2k said:

Welcome to Briskoda!  There is a wealth of knowledge on these boards!

Thank you Jaco2k, I appreciate it!

 

[nidza]

516Nm without a DMF to protect gearbox in between?

 

I am not so sure this will last. This gearbox is terribly expensive to replace.

 

[Rubes]

20 hours ago, nidza said:

516Nm without a DMF to protect gearbox in between?

 

I am not so sure this will last. This gearbox is terribly expensive to replace.

 

Thanks for comment, your opinion is appreciated

[octyal]

22 hours ago, nidza said:

516Nm without a DMF to protect gearbox in between?

 

I am not so sure this will last. This gearbox is terribly expensive to replace.

 

 

As is the crankshaft.........

 

[Rubes]

17 hours ago, octyal said:

 

As is the crankshaft.........

 

Out of your own experience or...

[octyal]

1 hour ago, Rubes said:

Out of your own experience or...

 Through work, this was removed from an Octavia that had been converted.....

[Jaco2k]

TBH, how many tuned cars are there out there and how many stories of failed gearboxes / crankshafts do we know about? Not saying it cannot happen - I had a tuned Saab 9-3 that blew an engine when either the crankshaft or a piston cracked, but I don't think it is a common failure on tuned cars.

 

Most reports about failure seem to go between clutch and turbo.

[Rubes]

Just returned from 150km trip...love my new Performance Clutch & SMF. Music off, ventilator off only engine sound in Normal / Sport mode. Even with OEM DMF my VRS was quick, but now it is more responsive, grabs higher revs faster, up-shifting  is faster, downshifting is easier, throttle respond is wilder, angrier, almost violent. The car has become more alive.

If my crankshaft & pistons & gearbox survived 85.000km on APR 1with OEM DMF clutch, I do not see why should it brake down because of lighter SMF? All kind of comments are welcomed, sure, but what interests me more, as a topic, is rather DMF vs Light SMF experience, then "how & what cracked my converted engine into peaces" which is completely different subject. One can replace OEM DMF with Light SMF on stock car, right? I doubt that stock engine is doomed to be broken because of SMF. Well, lets hear those people as well. 

[MoggyTech]

Dual mass flywheels are used to dampen torque spikes. Single mass flywheels tend to be used as owners feel (or are advised) that a DMF will not handle the extra torque after a remap. Personally I would stick with DMF as I would rather replace a £400 clutch and flywheel than a £6000 gearbox. Of course my feeling about tuning cars are pretty well known, if I want a faster car, I buy a faster car.

 

You will probably be fine, and as you are enjoying the feel of the car after conversion, then that's cool. 

[MoggyTech]

4 hours ago, octyal said:

 Through work, this was removed from an Octavia that had been converted.....

That's impressive. 

[grumpytwig]

Are these SMF kits for the VAG engines supplied with a sprung clutch?

 

Usually a DMF has a solid clutch but SMF kits come with a sprung clutch to maintain some of the give that a DMF provides, also reduces the likely hood of these issues people are talking about.

[Rubes]

25 minutes ago, grumpytwig said:

Are these SMF kits for the VAG engines supplied with a sprung clutch?

 

Usually a DMF has a solid clutch but SMF kits come with a sprung clutch to maintain some of the give that a DMF provides, also reduces the likely hood of these issues people are talking about.

Yes. To compensate the dual mass flywheel and it´s vibration damping, the SACHS Performance clutch kit (530+Nm) contains a clutch disc with torsion springs that function as vibration damper between engine and gearbox.

Edited 21 December, 2017 by Rubes

[Rubes]

10.000km on performance light SMF clutch kit and counting.

On 12/20/2017 at 14:09, octyal said:

 

As is the crankshaft.........

 

10.000km on performance light SMF clutch kit and counting. Gearbox & crankshaft? Never better but one must not loose hope

[Rubes]

30.000km on lightened SMF. Works like a charm 😉 Couldn't tell if it had any influence, but just scored my lowest fuel consumption on 230km trip: 4,8 lit/100km.

Edited 22 October, 2019 by Rubes

[JSM43]

On 21/12/2017 at 09:01, octyal said:

 Through work, this was removed from an Octavia that had been converted.....

 

[JSM43]

That is not a torsion break on your crankshaft, as you would expect if the cause was the flywheel. I would say it is pure and simple metal fatigue.

People on here are quick to ascribe cause from a sample of one! 

 

JSM

Chartered Engineer

[J.R.]

And the stress reversals of torsional vibration are what causes the metal fatigue, all it takes is a stress raiser to start from.

 

Exactly the type of failure I would expect provoked by removal of or a failed DMF or harmonic damper pulley.

 

Editted, as it has broken at the crankshaft nose end it points more to a harmonic damper failure but that and the DMF are all elements in an integrated system, remove one and it has consequences on the other.

Edited 27 May, 2020 by J.R.

[Rubes]

On 20/12/2017 at 14:09, octyal said:

 

As is the crankshaft.........

 

50.000km and counting. No issue what so ever. Would I do it again, from this prospective? Absolutely. DMF driving experience looks like bad dream. Couldn't tell if SMF affects fuel consumption by the book, but in reality it seems it does.

[Rubes]

On 27/05/2020 at 23:39, JSM43 said:

That is not a torsion break on your crankshaft, as you would expect if the cause was the flywheel. I would say it is pure and simple metal fatigue.

People on here are quick to ascribe cause from a sample of one! 

 

JSM

Chartered Engineer

I agree. I know a driver who has been behind the steering wheel for 6 years. His clutch dies regularly twice a year, crankshaft only 1 time. No, engine has not been "converted", no tuning at all. What went wrong? Driving style. It can be described as all or nothing. Start in the 1st gear ends with, either engine shut because of low revs, or screaming tires with too high revs. Other gear shifting is...modestly defined unpleasant. Uphill driving is in higher gear then one should expect, engine shatters and suffers. His guarantee right has been regularly denied by the service: driving style caused the failure.

[Alex-W]

I'm kinda of wishing I'd gone this route when I had to change my clutch earlier in the year.

A DMF is expensive and wears so much that you have to change it with the clutch.  

 

I've read it causes issues going to SMF, but as one guy (who runs a tuning place that mainly does jap stuff)  - it didn't seem to be a problem before somebody invented a DMF!

 

Back in the 90s or early 00s most stuff was SMF and there's plenty of reliable highly powered cars from that era, so I don't fully buy into the idea it's just going to kill gearboxes unless they now make them from chocolate.

[Rubes]

https://www.youtube.com/watch?v=QcZNGQDlhVQ

[nidza]

Do you always drive so gently? I wonder how often you use 500+Nm? I do TD occasionally and honestly, I am afraid of converted clutch.

 

BTW, very nice of you to come back after so long time with proper feedback. Usually topic starters disappear forever. Thank you very much!

 

[Rubes]

Your welcome Not always, kids were asleep after long exhausted day, so I gave them over  1 hour: 80km/h on highway for about 100km. Yes, fear is good stuff, keeps you from doing wrong things. In my opinion DMF is rather about undeniable driving comfort then constructional & engineering clutch/crankshaft/gearbox upset.

 

As for driving experience, DMF can not match SMF. Honda Civic Type R (2019), for an example, has OEM SMF. Does it broken crankshaft, here and there, brake the hood  at the the 1st cosmic speed? Of course not. Some Porsche models have OEM SMF as well, other cars too. Thanks for visiting this topic, I appreciate it