Clutch replacement coming up, and I'm thinking of swapping the stock flywheel on my 952 with a lightweight Fidanza flywheel.

But I've read a couple of recommendations to have them balanced before fitting, which bothers me for two reasons. Firstly, shouldn't a new flywheel be perfectly balanced when you buy it? (The only flywheels I've bought previously have come with entire cars wrapped around them, so I'm aware that I may just be ignorant here).

And secondly a quick round of phone calls tells me that it's very hard to find anyone in West London who can do the job, so there might be the added expense and delay of shipping it off to someone who *can*.

Can anyone with experience of these give me their thoughts?

 

Also... it crossed my mind that I could simple have some weight removed from the existing flywheel. If I ask a machine shop to do that when they resurface it, would the flywheel need rebalancing? There's place 20 minutes away that can resurface, but they can't do balancing

 

A machine shop with an engine balancer should be able to do this for you. The shop will probably have to come up with some sort of adapter to mount the flywheel to their machine. I would contact the Fidanza people about this ..The flywheels shouldn't have to be rebalanced once they leave their shop. IMHO.

 

I would agree on the balancing issue. They should be essentially perfect as manufactured. It's not like they heat the metal up and take after it with hammer and tongs!

The whole subject of balancing can get pretty technical in a hurry. But in general, you want to be balancing the entire "rotating assembly", not just one part.

I was using Search the other day for something entirely different and ran into a post by Michaelmount123 that showed a stock metal flywheel with some metal removed to reduce it's weight. There's nothing particularly Porsche or 944 specific about this. You should be able to find a machine shop that has been there/done that.

From a general physics standpoint, you get the most value by removing material that is near the outer circumference. This weight has the most rotational inertia and thus resists the revving of the engine most. Having a lighter flywheel will give you a engine that revs more freely, at least with the clutch disengaged . I think from a "bang for the buck" standpoint, this one is would be pretty far down on my list of things to spend much money on.

 

Thanks fellas, useful info.

I think, after some more reading around and phone calls, that I'll probably get a used original steel flywheel, and have a machine shop balance and remove weight from that as well as resurfacing. (Won't get quite as light, but I'm OK with that.) Still can't find anywhere local - the local-ish place said that an adapter was the problem... couldn't mount it on the machine for balancing. So I'll have to send it off, but it's a solution, and I can do the quick swap when I do the clutch.