loose valves

[BadDSM]

With the exception of brake discs, those holes are for reduced unsprung weight

those holes are to help disapate heat as there is more surface area exposed, not to mention helps scrape water from an otherwise flat surface, this aids in better braking during adverse weather conditions, the unsprung weight is a byproduct.

Not only to scrape water from the discs but to release the gases that build up between the pad and the rotor which can cause the pad to "gasdroplane" across the face of the rotor after the pads have heated up and started to gas. Brake fade will be caused.

[scratch]

Wow, I've never heard of gasdroplaning, where did you read or hear that? What magazine? Can you give the month of the article?

[The Buddha]

Hey I gasdroplane many times a day....
Cool.
Srinath.