The ATI CTS-V and Camaro ZL1 supercharger overdrive harmonic balancer upgrade kit is designed to enhance the 2009-2014 LSA supercharged engine. The ATI overdrive harmonic balancer kit produces excellent horsepower and torque improvements over the factory 556 horsepower and 551 lbs ft of torque while maintaining a safe level of boost and supercharger RPM. This harmonic balancer kit will increase boost by raising the RPM of your supercharger by overdriving it from the harmonic balancer. This kit does not replace the driven supercharger pulley on the supercharger snout.