Action Clutch Chromoly Lightweight Flywheels are the perfect upgrade for light to high tuned street and race vehicles. Our Chromoly Lightweight Flywheels stand up to extreme use and have increased durability through our heat treatment process. Action Clutch Chromoly Lightweight Flywheels have been tested up to 18,000 RPM, so they can truly last. You'll get low weight, superior engine response, and high thermal capacity—plus, it's resurfacable, giving it an even longer life span. You should note that noise, vibration and harshness (NVH) may be introduced due to the reduction of rotational mass.