These CNC-machined pulleys are made of lightweight 6061-T6 billet aluminum. Dyno testing our 5.5" underdrive pulley on a near stock L36 showed 3WHP gained at 6k rpm. In car testing shows only a 2 deg increase in operating temps over stock. Higher gains are possible depending on your engine combination. Pulleys are available in a high gloss black anodized finish.

• dyno proven horsepower
• lightweight design saves a pound of rotating mass
• increases water pump life expectancy
• better fuel economy

*One size larger than stock belt recommended