Porsche Enthusiasts Club Forum

Has anyone installed a lightweight flywheel on a 1975-1989 911?

So you are thinking of fitting one? My experience of lightweight flywheels is not on Porsche. But for me they fall into the same category as a race cam. They work on track but are a mixed blessing on the road. Depending how far you go. You will likely destroy the cars idle so it will hunt a bit & tick over too fast like it has a vacuum leak. But will accelerate like hell. It's a trade off. The gain depends on how overwieght the stock one was to start with. Also if your considering an alloy flywheel. There not as durable as the stock steel one & may need to be replaced in the future. Wouldn't go down that road again myself except for a car used mostly on the track.

Pretty much concur with JJ. Had a l/w one on the TR7, made by machining the standard one. But the standard one is a bit of a boat anchor,I think it lost 3kg after it's diet! On something like a 911 where it won't be that heavy to start with I'd leave it alone.
I'd also add that the view on l/w flywheels is generally because people put them on to cars with hot cams etc.

thanks guys.

Standard clutch is about 11lbs and lightweight about 6lbs. Im running some fairly hot cams so maybe....

If this car is used on the road you'll find it a pain TBH. I think the TR7 one was around 18-20kG so hence the diet!

yes road and a few track days. Im hoping my MoTec system will catch any potential stalls. But I know what you mean. I am in two minds about it.

Throttle response is greater, the motor spins up faster, however drops even quicker!

There are advantages if you are using the car for 'sports purposes' but if its an every day driver I'd give it a miss.

Purely for diving and performance = Great do it

A to B = Not really comfortable and becomes a problem.

Like anything its about balancing what the car is for and what it is going to be doing most of the time.

My car has a LWF, i prefer it to the standard type in the 64.
But it has caused it to stall sumtimes, makes more noise (dosnt bother me) and the idle is a little rough.
My car is booked in at chipwizards on the 20th to try and sort the stall issue.
I dont know how a LWF will affect an early 911 thou.

Interested to know how you get on at Chip Wizards on the 20th. Want to get mine sorted out there too but it has to wait as the wifes due to go into labour any day. It's only 20 minutes from here.

J.J, ill let you know on friday if he can work magic or not!