Pro's Con's dual mass or solid flywheel

[allan 295]

As title states interested in your opinions on the pro's and con's on these two types of flywheel, clutch set ups. The vehicle concerned will be a street car with the odd venture on to the track.

[BM WORLD 1264]

some info here

http://www.valeoclutches.com/Products/Clut...version+Kits/45

http://www.jbracing.com/flywheel-bmw6.php

http://www.trademe.co.nz/motors/car-parts-...n-481770240.htm

go solid , just have to choose how heavy you want it .

i have a 6.5kg solid steel m20type one in my e36 328i and its fine , gearbox rattles a bit at idle , more so when it idles lower when a/c is on etc. but if idle speed was more like 750-800 its ok

i have a 5.9kg jb racing ali one in my e34 544i v8

and a 7.5kg steel one in my e28 with m5 engine

all boxes chatter a little but thats just how it is.

have just done a e36 325i with a new beefier clutch and a 9.25kg solid m43 flywheel and its fine

but you can buy steel after market ones that weigh more like 10kg etc instead of 12.5kg to18kg etc

Edited June 5, 2012 by Brent HARTGE535i

[turbolizard 38]

Almost everyone will tell you to go for a solid flywheel. I did that when I replaced the clutch in my 540is and it works well. I am happy enough with what I have. However, I actually miss my dual mass flywheel.

Let me explain. The 540 is a luxury car with excellent performance. It is a really fun car to drive and it sounds awesome when wound up. On the other hand, I also love the luxury interior and comfortable cruising and the dual mass flywheel was a great part of that.

I used to think carpet in a car was just pointless extra weight, but times have changed. Gearbox rattle detracts from the luxury feel of the car and the clutch take up is sharper (that can sometimes be good).

The dual mass flywheel was so smooth and nice I can totally understand why BMW specified it in the first place. Don't automatically think the dual mass is bad. If you know how to work a clutch properly they are not weak. The characteristics also suit many of the BMW models very well. In an M3 things might be different.

[hybrid 1039]

around 6+ KG gearbox rattle is all in the weight of oil and mix you use.

There is a great balance of two redline oils I have found that eliminates the rattle all together for normal or spirted driving. The only time I have gearbox chatter is after 6-8 laps at the track. Otherwise I dont hear it.

[pureboiracer 0]

Not sure how bmws are effected by it but some vehicles use the d.m flywheel as part of the harmonic balancing for the crank and can induce vibrations etc when removed

[E30 325i Rag-Top 2918]

^^ What he said, certainly on the S50 / S52 motors this was the case and unless ALL the reciprocating mass together is balanced extremely well by the engine builder it could have a tendency to fly apart.

Probably only really applies to race / track cars - on a DD it shouldn't really be a problem, but then the benefits maybe not their for a DD either.

[Greg111 13]

Is the S50 a dual mass? Too many stories going round told by people who aren't in the know.

[Silver Fox 43]

Yes it is, hence Rag Top's comment.

[E30 325i Rag-Top 2918]

Too many stories going round told by people who aren't in the know.

I was speaking from my experience of two E36 M3 engines I worked directly on in the Uk that had this problem and one here in NZ that I know of first hand.

Great thing about cars, engines, gearboxes, DMFs, there are plenty of well qualified and experienced people who will all have wildly differing opinions. It's part of what makes life interesting IMHO.

[nzodea 25]

hopefully not highjacking this thread>>>

there seems to be benefits from the single lightweight solid flywheel with regards to spin up and acceleration. the disavantage is chatter/noise

are there any advantages for a dual plate clutch vs a single plate clutch with the lightened flywheel? does the dual reduce the weight savings significantly? Is it smoother but still gives the spinup benefits.

I am deciding which clutch set p/flywheel set up to go with for next session.

looking at a single mass light flywheel but not sure if a single or dual plate clutch set up is better

Edited June 14, 2012 by nzodea