ACT 2007 BMW 335i XACT Flywheel StreetliteBrand ACT Part Number 601180 Category Drivetrain Flywheels Condition Brand New Original Manufacturer Packaging Noticeably improved engine response and acceleration, OE to mild gear rattle; Heat treated forging for strength and toughness, induction hardened ring gears for maximum life; One piece construction allows less opportunity for failure and provides uniform efficient heat transfer from the clutch disc. No more warped inserts or loose ring gears;