Technical DMF to SMF conversion, anyone did it ?

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Technical DMF to SMF conversion, anyone did it ?

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JTD115
There is an aftermarket kit available, but it's kind of pricy.

The idea is to find a solution like in JTD105 (2.0 20v flywheel + 2.0 20v clutch).

The Abarth clutch is 235x20 like JTD115.
Is the flywheel dual or single mass on the abarth ?
 
JTD115
There is an aftermarket kit available, but it's kind of pricy.

The idea is to find a solution like in JTD105 (2.0 20v flywheel + 2.0 20v clutch).

The Abarth clutch is 235x20 like JTD115.
Is the flywheel dual or single mass on the abarth ?

I believe the selespeed versions of the Stilo abarth are dual mass.
 
When I had my 2.5D Range Rover I enquired about converting from a DMF to a SMF. I was told it was not a wise thing to do so as the DMF was specifically designed to reduce vibration and handle the extra torque of modern diesels. The mechanic said it could be dangerous, not sure why, maybe someone could shed a little more light on the pro's and con's of a DMF to SMF conversion?
 
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After a long chat with a mechanic, my understanding is that due to a diesels "lumpy" nature, they started to install DMF's to smooth out the transition stages in-between gears....nothing about handling extra torque?
The only way i can that it could would be something like a buffer because the box cant take the torque straight (but then would it not be better to just use a stronger box? :S)
In the mechanics general point of view, DMF's are a pain in the a** because they are so expensive and their lifespan is comparatively low....

I think there is someone on here that converted their DMF JTD to a SMF....or at least they started a thread that had the thought process in it...think they got bits from a multipla? but cant remember...
 
After posting I searched the internet for more info, found this.

Modern diesel engines generate high torque and as a result they need extra smoothing out or ?damping?. To help with this process a DMF (Dual Mass Flywheel) is fitted. This is effectively two flywheels that transmit the drive through a number of springs which cushion the drive to the transmission.
http://www.honestjohn.co.uk/forum/post/index.htm?t=61626

Basically it's a flywheel in two concentric parts or two facing flywheels stuck together with flexible compound to damp down transmitted vibration from diesel engines, improve gearchange quality and protect transmissions from torque reaction at around 2,000rpm, particularly the change from 1st to 2nd.
http://www.honestjohn.co.uk/faq/dual-mass-flywheels/

This video will help everyone understand HOW it does what it does.



Edit.
This is interesting to.
http://www.telegraph.co.uk/motoring/caradvice/honestjohn/6417776/Dual-mass-flywheel-appeal.html
 
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so basically what ive got from that is that they benefit engines that create 'larger' torque figures and they smooth out 'lumpyness' of a modern diesel engine now im REALLY :confused:

modern diesels are infinately less lumpy than those of years gone by id even possibly enjoy the arguement of them being less lumpy than some modern petrols. anyway all clutches have these little springs in that are supposed to take out a certain amount of 'snatch' (not that kind of snatch!!! :rolleyes: ) so i personally dont see the point in DMF

i have not seen DMF fitted to trucks and they produce upwards of 3000Nm, i have also found that trucks tend to be a proving ground for a lot of 'new' technology a few i know of are SRS, self levelling suspension, ACC, ABS, ESP, collision avoidance stuff, that cruise control that keeps you in whatever lane you were in, as well as Variable Geometry Turbos, EGR, and a whole host of other stuff ive probably forgotten about.

SMF all the way!!
 
anyway all clutches have these little springs in that are supposed to take out a certain amount of 'snatch' (not that kind of snatch!!! :rolleyes: ) so i personally dont see the point in DMF

SMF all the way!!

On all old cars, yes. But not on the Multipla (JTD 115). I assume it's the same on the Stilo? They have simply moved these springs from the clutch into the flywheel. That just means that there's one more thing that can break. :bang: Watch out for this if you plan on converting.
 
Yes all clutches do have springs but a DMF has huge very powerful springs that can cope with the extra torque modern diesels produce. By converting to a SMF you removing these large powerful springs from the drive chain allowing the lumpyness and torque to be transmitted direct to a greabox that isn't designed for it.

By removing this "cushion" your stressing other components.
 
Watch the video from 2:15 onwards to see how the huge springs of a DMF work. A SMF does not have these huge springs so the huge pulses of torque each power stroke produces is transfered directly to the gear box. Thats not good. The transfer needs to be smooth and thats what a DMF helps to do and is the reason modern diesels are so nice to drive.

I'm not saying don't convert from a DMF to a SMF I just think everyone should be aware of what the DMF does and any possible consequences of removing the DMF.
 
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Yes all clutches do have springs

Like I said in my last post, it doesn't on the Multipla 115 JTD. Check this picture I borrow from eBay. There is no springs on the clutch disc, it's all in the flywheel.
101617-dbb03-f2b1b8_m.jpg


I can imagine it will cause quite a lot more stress on the rest of the drivetrain if the DMF is changed for a SMF, without changing to an "old style" clutch.

I have never seen a Stilo clutch, so I can't guarantee that they are identical, but it's worth remembering when considering a flywheel conversion.
 
Like I said in my last post, it doesn't on the Multipla 115 JTD. Check this picture I borrow from eBay. There is no springs on the clutch disc, it's all in the flywheel.

I should have been more specific. The springs I was refering to are positioned differently in different types of "clutch setup".

A SMF setup has springs incorporated into the clutch plate for damping, ok for petrol and older diesels, not adequate for modern diesels.
Clutchdisc.jpg


A DMF has springs incorporated into the flywheel for damping, thats why there's no springs visible in the picture you used from ebay.

Most road going vehicles have some sort of damping in there drivechain. Motorcycles usually have it incorporated into the rear wheel.
 
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The springs basically do the same thing, just there is more space in the flywheel so they're placed out wide. The rubber provides some dampning also.

They have moved from a single mass flywheel, dual mass clutch to a dual mass flywheel, single mass clutch.
 
I should have been more specific. The springs I was refering to are positioned differently in different types of "clutch setup".

I see, then I just misunderstood. :) The point is that if you do a conversion from DMF to SMF, the clutch have to match the SMF. If not it could be a bumpy ride. :)
 
the arguement seems to be that DMF offer more 'cushioning' for the diesels drivetrain so swapping to a SMF would somehow transfer more vibrations into the drivetrain, which it wasnt designed for, therefore instead of damaging the DMF you would end up damaging the next weakest link in the drivetrain... it seems to be the biggest killer of DMF is overheating and overstress of the rubber component due to improper cluch usage i.e. riding it on inclines and 'locking in' torque forces i.e. leaving it in gear when parked on inclines... but even emloying these practices on a SMF will cause damage the only difference is that the damage is done to the drive/friction plate in the clutch rather than the flywheel its self.

IMO this arguement of torque doesnt really stand because the torque is created when the clutch should be fully engaged anyway...

all i can see is its a different way of having a cushioned transfer of drive
take for example the different ways of turning on lights you could have
feed>fuse>switch>bulb>ground
-OR-
feed from ECU>control module>ECU>bulb>ground back to ecu

my point being that both work just as well but end up with the same resolution to a problem.

the only advantage to the ecu controlled bulb would be that it can sense if the bulb is blown and report on a the dash that said bulb is blown but if the ECU or control unit take a funny then it will be more expensive than a fuse/bulb to replace... the only advantage i can see to the DMF is that apparently it offers smoother transmission of power between engine and drivetrain, but as some of you may know its more expensive to fix if/when it does go wrong
 
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im running this gsr kit from italy
s1030464.jpg

if you have time read through this thread
http://www.alfaowner.com/Forum/alfa-147-156-and-gt/155491-slipping-clutch-on-1-9-jtd-question-3.html
it was expensive all in all(went for uprated alfa Q2 diff at same time)
basically unless your aiming for masses of power and torque and want the revyness(this smf is 3 kgs lighter than std dmf) i wouldnt bother or look at getting uprated springs into the dmf for best of both worlds.
gearbox will suffer more no doubt, and sitting at lights etc theres a bit rattle
heres a vid in neutral clutch in and out
 
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That SMF produces a lot of "Chatter", not sure I'd want that.

all fitted now, big thanks to allitalia wrexham:thumbs: , went to fiat for the bearing in the end,gotta bed in new clutch for a few hundred miles first before i can really test out,but first impressions are good as it doesnt rattle in idle like id read is normal for smf on vag tdi cars,peddle pressure i would say is a fair bit more than oe but nothing too hard(way too soft as standard i thought anyway)easy enough to find bite after a few junctions.

You said there was no rattle/chatter when you originally fitted it. There obviously is now so something has worn quite quickly.

"Clutch "chatter" is often caused by an overheated clutch (normally from "slipping" the clutch when starting on an incline) or from oil on the clutch disk. In either case, the clutch must be replaced"
http://www.edmunds.com/car-technology/when-fact-meets-friction-the-basics-of-clutch-operation.html

As the prices of a DMF and a SMF you got were similar what made you choose the SMF?
 
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