The stock dual mass flywheel is catered to maximize smoothness and fuel economy, at the expense of engine response and performance. Dual mass flywheels are also prone to failure, particularly on high performance applications, and are expensive to replace. The Turner lightweight flywheel is designed to offer the perfect balance of comfort, smoothness, durability, and performance on any N54 powered vehicle. At 18.6lbs, 10 lbs lighter than stock, it offers significantly reduced inertia for quicker throttle response, improved rev-matching, and faster acceleration. However, unlike ultra-light aluminum flywheels it still offers a smooth idle, quiet operation with minimal increase to NVH, and smooth OE-like engagement for easy daily driver duty. The Turner N54 lightweight flywheel is precision machined from heat treated, stress relieved 4140 chromoly steel and precision balanced to exceed OEM specification for smooth engagement, even wear properties, and maximum toughness. It is then SFI certified which not only requires minimum material quality and strength requirements, but also a 3rd party lab test to spin the flywheel to 1.5x redline for 1 hour to verify it will not burst under the most extreme operating conditions. With the combination of world class in-house design, material quality, precision machining, in-house CMM quality inspection, and rigorous testing, you can have the confidence that you’re getting the best flywheel available. When paired with a Turner recommended ACT clutch, you’ll get a more engaging driving experience with un-matched performance, reliability, and durability. For vehicles with a 8 bolt flywheel and build date of 01/2009 or earlier Features: Precision machined from 4140 HT heat treated, stress relieved chromoly steel Black oxide coated for corrosion resistance on non-friction surfaces. 8620 steel pilot bearing pin, case hardened and precision ground for maximum wear resistance. Precision balanced to exceed OEM specification SFI 1.1 certified to ensure safe operation under extreme operating conditions Specifically designed to work with N54 architecture clutches Step height designed to optimize clamp load and maximize the usable range of clutch wear for a long service life Performance: Turner Flywheel 18.6 lbs 10 lbs lighter than the factory BMW flywheel (Stock Flywheel 28.9 lbs) Faster revs Improved throttle response Improved acceleration Sportier driving experience Turner recommends: Street: ACT Heavy Duty Track: ACT Xtreme for high torque cars or OE 335is LuK (with 440lbs-ft or less) Stock flywheel weight - 28.9lbsTurner single mass flywheel weight = 18.55lbs Single Mass Flywheel Conversion: Audible chatter from the transmission after installation is considered normal. As with most single mass flywheels, there is less dampening in the flywheel to reduce "gear noise." This chatter noise may be more present when the transmission fluid temperatures are hotter and may be intensified by other modifications. Most gearboxes will experience some chatter noise at hotter temperatures. Please be advised that this noise will disappear once the clutch pedal is depressed. This symptom may be lessened by adjusting transmission fluid weight, turning off electrical/driveline consumers (A/C, High Beams, ETC.), and by raising the RPM slightly. Installation: Flywheel Hardware: For added peace of mind, apply Blue or Orange Loctite when installing factory flywheel bolts that do not come with pre-applied threadlocker.