ATI Super Damper Crank Pulley for 4B11 Evo X

The ATI Super Damper for Evo X is available in two versions. The "Street" version offers a 3% under-drive for improved dampening and increased power and is a direct OEM replacement. The "Race" version offers a larger diameter and no belt drives.Unlike unbalanced underdrive pulleys, which offer no protection to high performance engines, the ATI Super Damper provides balanced dampening of torsional crankshaft vibrations. The 3 external bolts allow for the mounting of A.R.E.'s dry sump mandrel to the damper (A.R.E. p/n 2750B).The ATI damper comes with 360° laser-etched timing marks and exceeds SFI 18.1 Safety Certification.Vehicle Fitment:2008-2015 Evolution X 4B11 Damper: Part Number: Diameter: Weight: Street Version 918253 5.67" (OEM Size) 6.00 pounds Race Version 918254 7.07" 6.15 pounds Features:• High horsepower street & race versions• Dampens torsional crankshaft vibrations at all RPM levels• Protects against engine harmonics• Street Version: Direct replacement for t