by CAVEMAN » Wed Sep 22, 2010 6:51 am
lighter wheels reduce whats known as the un-sprung mass. This means that the suspension works more effeciently as it doesn't have have a great whacking weight on the end of it.
The lighter the whole suspension assembly the better, as it reduces inertia...so the suspension can change direction a lot quicker and be more responsive overall.
However as the whole set up here is on a road car, and you ain't changing the suspension set up then I doubt you will notice much difference, but lighter by 7Kg over the PFF's is quite a lot!
I don't agree with a cast wheel being lighter than a forged wheel buddy. Casting is basciually pouring the molten material into a cast..and as the material isn't under any stress then they usually need more material per given wheel design to acheive the same strength. Whereas forging takes a blank bit of material and deforms it under pressure. This plastic deformation increases the yeild strength so doesn't require as much raw material, so therefore is lighter.
There is also the heat treatment aspect of it too, and the fact that forged items will keep thier shine a lot longer than cast items too, as cast items are still very porous.