ATI Performance is well known for the improved harmonic damper best used for supercharger or any forced induction applications. Here at Beefcake Racing we use them on all our builds to help control excessive engine crankshaft vibrations causing a loss of power. These dampers are available in steel or lightweight hard-coated aluminum and come with Laser engraved timing marks. Exceeds SFI 18.1 specs. Beefcake Racing is an Authorized Dealer for ATI Performance, call 1-855-827-7223 for guaranteed lowest prices.