GFB Lightweight 3 Pulley KitGo Faster, Add Lightness! Less is more. New Lightweight Pulley Kit for BRZ 86 FR S. Like all GFB lightweight pulley kits, you can feel the improvements: Sharper throttle response Engine feels more willing to rev Stronger urge These, like all GFB pulleys begin life as a single 6061 T6 aluminum alloy billet, and are then precision CNC machined to exacting tolerances under total quality management system ISO 9001. We then anodize them black for a