My SIL just bought a porsche with a dual mass flywheel.. the car needs a clutch. We were discussing the possibility of putting in an earlier stock porsche single mass flywheel or even a lightweight flywheel.

Is the only purpose of the dual mass flywheel quietness of operation?

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Mostly correct - smoother operation rather than quieter. I can understand the replacement of a dual-mass with a lighter weight flywheel (racing), but if someone can afford a Porsche, then that someone should be able to afford the dual mass flywheel.

BTW, what's "SIL"? Sister in law?

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- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600

HI Tom, Just thinking about it off the top of my head, I think it has at 2 reasons, an increase in surface and contact area, like a multi-plate clutch, motorcycles use these types today and many of them have a "wet" clutch for wear and cooling purposes. Also allows a smaller flywheel and less mass to accelerate and decelerate.

Two, the mass and weight can be kept down, for accelerating purposes, and flywheel effect, when putting large amounts of power to the transmission, to the differential and finally to wheels and the rubber to the road. And then I guess just because they can.

YIA... Paul

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SONNY was right...Nobody Cares.
Calogero, from the movie, "A BRONX TALE."

Dual mass Flywheels house dual clutches, more surface area can handle and transfer more engine torque, Dual mass systems are used in high torque engine application, turbo and superchargers. Dual mass flywheels Dampen engine harmonics which can cause gear rattle and drive train vibration. With today’s new clutch technology you could use a high performance single clutch system.

Which Porsche model do you have

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Steve Cattaneo www.mastertechtrans.com


03 SL500
02 MB AMG
87 560 SEC
87 300D
928S 83
85 928 S2 EURO

my son in law has a 95 911 which he bought to fix and sell in the spring. It is a rather nice looking pearl white cab with a stick.

It is our impression that the dual mass flywheels are problematic. Is that not correct? I was not aware that it includes a dual plate clutch.

tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

My Golf TDI has a dual-flywheel, which they replaced once on warranty.

__________________
1991 300 SEL
218,000 Km

"Xsbank's rules of mechanical intervention: Always go for the easiest solution first; 90% of what ails a gasoline engine is ignition; After that its all a WAG."

What is a dual mass flywheel. It sound like what I call a multi plate clutch. Is that it.

John Roncallo

My mistake, Dual mass flywheel use one clutch disc, Dual clutch systems use two discs. Some how I intermix both systems in my mind. Dual mass flywheel can handle more torque that a conventional clutch system, problematic when the engine may produce more torque (performance modification )than the stock dual mass flywheel can handle
911 is my favorite Porsche

__________________
Steve Cattaneo www.mastertechtrans.com


03 SL500
02 MB AMG
87 560 SEC
87 300D
928S 83
85 928 S2 EURO

Two flywheels between a disc.


http://www.luk.com/content.luk.de/en/products/dampers/zms_sv/zms_sv.jsp

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Steve Cattaneo www.mastertechtrans.com


03 SL500
02 MB AMG
87 560 SEC
87 300D
928S 83
85 928 S2 EURO

I googled it and found that it is a system that is intended to make the car shift like a lightweight flywheel but have dampening characteristics of a heavy flywheel. Apparently there is a spring or springs which allow the two masses to rotate in relationship to each other somewhat like the disc on a clutch plate but more complicated. I think that running the car hard may wear it out prematurely, among other things.

I think I will recommend to my SIL to find a good used flywheel that is not the lightweight design or the dual mass design and simply install that along with a new clutch assembly.

tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Can't the clutch be changed without changing the flywheel? From the link to the LUK site, it appears normal clutch disc and pressure plate are used.

I say if the car has so many issues and it needs a clutch and may have a flywheel problem you should tell him to insure it and leave it out on the street with the keys and the title in the glove box...by the way, what is his address and where will my Porsche be parked, what color is it again????
Other than my dumb joke I have nothing to contribute, good luck with the car, it sounds like it is a nice one. i like the Cabriolets alot.

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Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red

I believe the clutch can be changed without changing the flywheel, but the dual mass flywheels have a bit of a reputation for being problematic and after a bit more conversation with him I find that the car might see some track time along the way and so getting rid of the dual mass flywheel would be a good idea. I think having a normal or one piece lightweight flywheel will be considered a plus on resale. Also the dual mass flywheels are not supposed to be resurfacable.

I am told though, that my favorite machinist has developed a way to resurface them. (not surprising).

Thanks to everybody for their comments.

I will pass along my comments to my SIL and daughter and they will do whatever pleases them!

Tom W

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

It actually looks to me like a harmonic balancer on the opposite side of the engine.

I believe from the picture the clutch disk and pressure plate is placed just past the second flywheel in the conventional manor. The real difference is that 1/2 the mass of the flywheel, the part that the clutch and pressure plate bolt to is mounted to the primary flywheel via an spring and damper system.

I see this as a useful means of low RPM smoothness while driving especially for people who don't know how to drive. As far as I'm concerned for performance it's a boat anchor.

John Roncallo

The other issue is that the dual mass flywheels can't be turned - when they're worn, you must buy a new clutch kit. I wouldn't recommend "turning" a Porsche flywheel anyways.

__________________
- Brian


1989 500SEL Euro
1966 250SE Cabriolet
1958 BMW Isetta 600