Go Fast Bits GFB 13+ Subaru BRZ / 13+ Scion FR-S Lightweight Aluminum Water Pump Pulley - 2223 $125.00 $112.50 It might be hard to imagine how reducing the mass of a pulley makes a car go faster, but accelerating a heavy factory pulley from say 3000-7000 RPM in a second or two saps a measurable amount of torque. GFB Lightweight Pulleys reduce inertia by up to 85...