View Single Post
Walt Fricke Walt Fricke is offline
Registered User
Walt Fricke's Avatar
Join Date: May 2004
Location: Boulder, Colorado
Posts: 5,697
Porsche Crest

A stock 6 bolt flat flywheel (1970-1977) weighs about 8 pounds. "About" because all I have for weighing at this weight is a bathroom scale.

For reference, on the same scale an RSR style flywheel weighed 7 pounds. An aluminum 5.5" Tilton style flywheel (with pilot bearing) weighed about 5 pounds, but you would not want to use this kind of clutch on the street.

You can do good things by being careful about which pressure plate you use:

The "aluminum" Sachs (cast iron center plate, aluminum outer housing) weighs about 8 pounds. This is what your '74 came with. The iron PP (iron outer housing) weighs about 12 pounds. You don't want one of those. And for really light weight, there is the RSR 4 pound PP, which uses an aluminum center plate with a ferrous spray coating on the wear surface.

I don't think you will have a problem running a lightened steel flywheel on the street. I ran one for years.

Now whether switching is worth the cost and effort, that is another matter entirely.

The one pound or so differencein the RSR steel flywheel all came off the all important outer inch, though, so its effect on the MOI exceeds its mere mass. Here is what a 9 bolt one looks like, but the 6 bolters are the same (some also have lightening holes between the pilot bearing and the wear surface).

Walt Fricke
Old 01-02-2007, 12:49 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)