Cupcar

Here are some weights I though might be of interest regarding the Dual Mass Flywheel (DMF) versus the Single Mass Flywheel (SMF) components for a GT3 weighed by me on my balance beam scale:

DMF= 30 pounds (includes integral starter gear)

SMF= 11.8 pounds
SMF Separate Starter Gear= 1.3 pounds
Total SMF equivalent to DMF assembly= 13.1 pounds

DMF Driven Disc (Un-sprung) =2.8 pounds
SMF Driven Disc (Sprung) = 4.3 pounds

Net saving= 15.4 pounds or exactly 7 Kg, what Porsche says it saves for the 964 RS, the first car that used the SMF parts.

I hope this is not a repeat of what others have posted.

FixedWing

Great info! Thanx.

So is it possible to put any meaning to this figure? How much difference should 7 kg on the flywheel make?

Stephen

Z06

The engine will use less HP to turn the drive train.. quicker acceleration.

arenared

Pardon my ignorance as it is not obvious to me, but what SMF and clutch did you use? Is it a specifically lightweight aluminum one?

FixedWing

Sure, I know the general effect of having less rotating mass. But how much difference does it really make? How much quicker will the engine rev in the lower gears? Is 7 kg meaningful in comparison to the total rotating mass of the drivetrain? Can it be quantified in some way?

Stephen

Nordschleife

lightened flywheels do indeed make a difference. They are one of the cheats used by race teams when they need to win in front of the sponsors. They get caught but the sponsor goes home happy.
I have seen beautifully made steel and aluminium flywheels. These are prone to problems as the torque causes the steeel screws to create wear in the aluminium main body, be warned. The better German manufacturers are able to produce all steel lightweight flywheels.
The McLaren F1 has no flywheel, how's that for a weight saving?
R+C

DanH

Does make the car sound like a diesel at idle though! At least my GT3 RS clatters away like one sometimes!

Sloth

Good information CupCar, thanks for posting.

Sloth

The parts being talked about are the same as whats used in your GT3RS. Its a slight rattle from the flywheel when the clutch is out or accelerating from low RPM's. The noise is in character for the car and not much of a bother to me.

DanH

It doesn't bother me, part of the character, but it can be a bit worrying until you get used to it. On startup it sounded awful once!

Cupcar

Answer: The flywheel components are factory light flywheel components used on the GT3 Clubsport, GT3 RS and GT3 Cup.

Cupcar

Answer: Car owner says:" It came out just fine….the throttle response is noticeably better and the car does seem to be even happier to rev than it was before! The idle is unchanged i.e. it is still a little rough. There is a some gear rattle at idle but you really have to be listening for it and there is also somewhat noticeable rattle on deceleration at low revs reminiscent of my 911SC years ago. All of this is completely consistent with the character of the GT3 and all of the cars should come with the SM flywheel IMHO not just the RS and Euro Clubsports."

DanH

Yep I agree they should all have had them. It has no negative effect on drivability that I can detect. Idle isn't at all rough, just clattery.