The ring gear flywheel size determines your clutch size. The flywheel has to fit within the bolt circle of the crank and match up to the pressure plate. It’s only one part of a system.

If you’re running a heavy car, you’ll need more torque to move its weight. A steel flywheel can help. The same holds true for classes with engines that don’t turn the higher rpm. If your class has a cam rule limiting your engine to a 440-460 lift cam, you can use the steel ring gears flywheel.

If you’re looking for a standard configuration aluminum flywheel that can hold up to the rigors of racing, there are some available that use friction materials consisting of bronze and iron. The different material allows for better contact between the clutch disc and flywheel while the aluminum saves weight. Those contact areas can be replaced when needed.

When changing a flywheel and clutch or pressure plate, always change the throwout bearing. It’s cheap insurance. Throwout bearings are responsible for 85 percent of clutch wear.

Throwout bearings require an air gap between the bearings and the pressure plate. The recommended size is usually 31/416-11/44 inch, but the gap will depend on the style of clutch. If it’s not spaced properly, it will hang up. We all know what can happen to an engine when a shift is missed. This clearance is even more critical on the longer styles. The wrong gap will wear out the bearing faster and take other parts with it.

Use only approved fasteners when mounting the flywheel the movie to the crank and the pressure plate to the flywheel. The same holds true for automatics and mounting flexplates. Always check the length of the bolts so they don’t bottom out. Use the crisscross method of tightening, and they’ll need to be torqued. Also, do a rotation check so they don’t impact the block after they pass through the crank. If you have a damaged ring gear, it can usually be replaced. Manufacturers sell replacement ring gears that fit both steel and aluminum units.