Lightening the flywheel-anyone ?

[mikeesik]

Curious if anyone has experimented with the fly-wheel weight.

Any good results from purchasing a lighter one or machining one to reduce weight ?

[Danglerb]

Not on a stock motor.

928MS sells an aluminum one I think.

Greg at Precision Motion has new very very nice racing clutch with very nice street manners and a $4k price tag.

928 transmission shifts slow, so not a great interest in dumping money into lighter flywheel without substantial power mods.

Precision Motorwerks
928 Motorsports® LLC - Porsche® Performance Parts - New Aluminum Flywheels for the Porsche® 928 - Porsche® 928 World record Holder 216.63537 mph

[Pete R]

The flywheels aren't really that heavy especially when you consider the crank it's attached to is around 55 lbs. You could go back to the dual clutch for better holding and less rotational inertia (I know that probably not the scientific term)

[JK McDonald]

Hey mikeesik, Years ago I experimented a bit with lightening the flywheels in a few track cars to decrease the time it took for your engine rpm to recover when coming out of a hair-pin curve. It takes the removal of quite a bit of metal before much of an advantage is finally realized. The down side was the negative affect it had on the smoothness of the engine at low rpm. Depending on how much weight you removed - it can make a previously fine running engine feel like you now have a miss at idle.

Michael

[mikeesik]

I figured that removing some weight would make lower rpm's and idling a bit of a 'racing cam nature'.
-makes sense to me.
Had no idea of the weight of the crank. !!

-I was curious on the engine being to slow from a return of high rpms.
(rotational inertia)

Perhaps this would work overall on an engine with bad compression. (?)

-Thanks guys.

[Danglerb]

I drove a 911 once with a lightened drive train. It had no inertia, release the clutch even slow and unless you give it the right amount of gas it dies, repeatedly. Too much gas as you look like an idiot. Worth it maybe on a track car in a class that allowed it, but otherwise not too practical.

[Illini-heel]

Originally Posted by Danglerb

I drove a 911 once with a lightened drive train. It had no inertia, release the clutch even slow and unless you give it the right amount of gas it dies, repeatedly. Too much gas as you look like an idiot. Worth it maybe on a track car in a class that allowed it, but otherwise not too practical.

Sounds like my 2 stroke moto-crosser. So light, it sounds like it's dead at the apex of a corner; but then: BBBRRRRAAAAAAAPPPPPP and I'm screaming down the next straightaway. Bliss.

[Fabio421]

I have an aluminum flywheel that I purchased for a 928 turbo engine build that I've never completed. It is amazing how light it is compared to the original.

[mikeesik]

hello Fabio.

Nice to read from a fellow 8'er.
You've been busy.......and passionate.