FLYWHEEL LIGHTENING

[simo96]

Hoe much can you remove from the flywheel without it going bang on a 99/900?

[SwedeSport]

I have been running one in my 86 900 that has about 5 lbs taken out of it. I think you could probably go a little more than that. If I were to do another one, I would have the weight reduced on the outer edges as much as possible. My last one had most of the weight removed from the back in the recess towards the center.

It's been in the car for almost 10 years without a problem.

[Luke]

I had this one made for my 16V engine. It is based on drawings of what the works team did.
I forget the exact weight, but its light :)

[DrewP]

The same guy who did Luke's did the flywheel in my '85 without all the pocket work. It's got the back face turned down some around the mounting flange, the surface is cut a little shorter, and some taken out around the outer diameter next to the ring gear. It's down to sit flush with the edge of the pressure plate.

Stock is 22 or 23 lbs, I think mine weighs 15 or 15.5 lbs, so 5-6 lbs without too much work, more if you go berzerk.

The Fidanza aluminum flywheels weigh about 10-11 lbs if you can find one, I picked up a used one with a clutch for about $200 a couple months ago.

[aero84]

HI Guys

We have talked about this before..
In Sweden you can buy a flywheel at just 4,9 kilo.
But its not sutable for turbo cars...

www.folkraceshop.se

[Geoff]

4.9 kilo = 10.8lb
800 SEK = 118 USD = 75 GBP

Sounds like the best "bang for the buck" out there.
It looks like you could put timing marks on from about 0° to 15° or 20°.

Just find a local, inexpensive, machinist; shipping from Sweden would not be very cost effective. I'd have the machinist put some radii on some of those sharp corners though.

Jakob, is it not suitable for turbo cars because of the diameter of the clutch pressure plate and disk? I would think you might be able to use it on a turbo car with a stronger clutch that has the same diameter as the non-turbo cars.

[KoogiA17]

I happened to have a flywheel drawn up in CAD so I had a little play around with what could be removed.

Got it down to 6.1 kg/13.5lbs without the need for machining holes / deep recesses. Was still conservative so more scope for removing mass.

People on UKSaabs took theirs to Puma Racing to have machined. (Are you rallyv4?)

[Crazyswede]

just shipped 2 boxes to australia...one weighed over 10 lbs and had $800 insurance on it...cost $100 to ship that box via usps.

[Geoff]

Do you mind sharing your CAD file?

[aero84]

Hi Geoff

I will check with folkraceshop.se why they say its not suitable for turbo engines.
And then I will be back.

[simo96]

Yes I am rallyv4, so I know Dave Barrow quite well. My flywheel has had quite alot removed from the rear, I will measure the thickness that is left, but it must be around 8mm.
Dave after talking to Dave Barker (Puma racing) recon you probably dont want to remove too much out of the rear due to strength reasons (ideally we know we want to remove mass from the outer dia).
Whoever did mine drilled some nasty holes to mount to a lathe face plate, then managed to inprint the face plate into the clutch surface.

The Turbo has alot more torque than the N/A engine, so I guess that Swedish item is a bit near the bone!

[Jon1]

Here is a flywheel that has been modified to be used with T5.
Jon
jon1..

[simo96]

Lukes flywheel looks the Business! Most of the weight removed from the outside. I think I would need to start with a std flywheel. Once you have taken a load out of the rear you wont have enough material left to mill the front (obviously the guy who have the car before me went for the cheaper option).
I have a 2.3 item, but I carnt see the point in wanging all that weight around when the std flywheel with an uprated cover and lining will do the job (plus the 2.3 is not legal for historics).

[aero84]

Hi!

I have now recived ansver from Sweden, and they say that the flywheel they have does not fit the turbo clutches!!
That is what they say, but I dont seem to remember that there are any diference in the clutches one a NA verses Turbo car....

[DrewP]

Maybe the outer diameter of the larger disc hangs off over the area of the cutouts a little bit?