Flywheel Lightening [Archive] - SaabCentral Forums

: Flywheel Lightening


Nuts
01-03-02, 11:46 AM
I am considering lightening my flywheel.

I have seen "Saabine's" flywheel on the Turbo Team Europe site (http://web.inter.nl.net/users/turbo-team-europe/flywheel.htm), The site states that approx 2kgs was shaved off.

I would like to know of any more specific weights anyone has had taken off their flywheel as I am seriously considering having this done very soon.

Janne Selinummi
01-03-02, 01:27 PM
The Swedish Dynamics aluminium flywheel weighs in at approximately half what the OE flywheel does.

Other say it works fine, while some people claim it causes driveability problems to some extent. I think it's down to what other mods you have.

I think the reasonable way is to use the original flywheel and grind off 2-3 kgs - any more will be a risk, and you will notice the improvement with such a smallish reducement in weight.

Nuts
01-03-02, 01:44 PM
I am kinda shyong off getting an aluminium flywheels due to some of the horro stories I have heard of them shattering. Something I don't really want to experiance. :eek:

Any ideas on a more specific weight that can be taken off without any runinng problems? How much have you had taken off your flywheel?

Lui
01-03-02, 04:08 PM
What drivability problems might occur with a Swedish Dynamics flywheel?

Keith
01-03-02, 05:44 PM
You'll need more revs to pull away.
Which will put more heat into the flywheel initially, however being ally it should also dissipate quite quickly...
You will also need to apply throttle earlier climbing hills off boost.
Basically, while you are off boost it will feel like you will have less torque.

Janne Selinummi
01-03-02, 05:52 PM
Personally I think a 2 kilograms lightening should be enough and still cause no problems.

ianlax55
04-03-02, 09:31 PM
i had mine replaced with a lighter one and noticed substancial acceleration improvement.

Nuts
05-03-02, 06:40 PM
Any ideas on the specific weight that was taken off?

I am thinking somwhere around the 2kg mark, but would much prefer to know an exact figure that someone has experiances of.

Matthew
24-09-04, 07:02 AM
I am kinda shyong off getting an aluminium flywheels due to some of the horro stories I have heard of them shattering.
This (http://www.mymazdarotary.com/various_videos/mates_rotary_videos/rotary_wagon_flywheel_explosion.avi) (9Mb file) is what it might look like :o

Eric van Spelde
24-09-04, 07:55 AM
Saabine's flywheel (-M89 type): stock 9.0 kg, now 7.0 kg.

I weighed a later flywheel at 10.25 kgs on Sweedspeed's scale (so should be quite accurate).

john-w
24-09-04, 11:56 AM
Sam,

Don't be tight get the real deal...

saab90089
24-09-04, 02:27 PM
i have a lightened flywheel, done be NLspiked02's motor man........its calling my name i just don't have the time to swap it out.

I know NL said it made a nice difference in his car.

ian

johniemi
27-09-04, 08:50 AM
Is lightening the flywheel just as easy as putting it in a lathe, milling off ca. 2kg's of material and then checking that the wheel is still balanced?

Where exactly can you take the material off from so that the wheel is still durable?

-John

Eric van Spelde
27-09-04, 09:03 AM
You have to be very aware about where to remove material. When it breaks away from the bolts at 6,000 rpm, you can about guess what happens (fortunately the clutch side on a c900 is to the front of the car so at least you probably get to keep your legs...). Also it always need to be rebalanced.

Please 'do not try this at home'! Only give your flywheel to an automotive machine shop where they know what they're doing. If you have to explain them what you want to do, run...

johniemi
27-09-04, 01:03 PM
Thanks for the tip! Will talk to the local rally car tuners (and there are LOTS of them around here). Problem is, they mind their own business and rarely do any machine work for street cars. Guess they have plenty to do with their rally cars, their friend's rally cars, their grandma's rally cars etc etc.

-John

Vince T
27-09-04, 02:59 PM
I ran a Swedish Dynamics FW coupled to a 4-puck copper disc. It was waaay aggressive, and I basically machined out the flywheel just by driving. Starting uphills was a complete *******.

Then I switched to a lightened stock flywheel coupled to a 6-puck Swedish Dyanamics kevlar composite disc. This was pretty decent, but I didn't get much mileage out of the disc. Or rather, not as much as I would have liked. And it slipped.

This past year I've used the lightened stock flywheel, but now with 6 copper pucks on the same disc (had it rebuilt). Works pretty decently, but a) too much start stop builds up heat very quickly and makes the clutch difficult and b) it also slipped, but only at very high rpm on the dragstrip.

I've since put the aluminum FW into my 99 rally car coupled with a stock organic disc and that's cool. The response is nice.

What I'd like is one of the twin disc setups that Scanwest sells, but that's near on C$2k, quite expensive! I have a spare 9000 pressure plate, brand new, sitting around so I may try something with that soon.

I'm thinking the aluminum flywheel is a mild organic-metallic composite disc would be almost right, if it can hold the power.

Chris S
27-09-04, 07:42 PM
I had about 4-5 lbp takes off mine and liked the result. money well spent.