Ok Glen, My $.03 Race car: yes Alum. Flywheel, as Jim said we're at high rpm's, quick shifts, etc. Not having to worry about coming off the line (Stop light) Std. flywheel: you're not gaining anything. Lightened: quicker revs, less internal mass, no slipping of the clutch coming off the line. I went from stock (28lbs) to a lightened (22bs) in the V-8 RX-7, made a HUGH difference without any drivable issues. You know I hate to disagree with patrickt, but sometimes you take your chances
Cheers TommyRot.