Many people don't know what influence a flywheel has when modifing your vehicle, and that is why We decided to do a little write up about them and why the different weights. A flywheel has a really important job that cannot be overlooked. If you dont have a clue what is the difference between them and why the different weights, it may be difficult to choose the best flywheel for your engine, that is why first of all you need to define the purpose of your vehicle. A flywheel must carry the momentum of the crankshaft with enough energy left over to compress the intake charge with a minimal drop in RPMs, which would negatively effect the engine as ignition would happen to soon, causing an overload on the crank bearing.
Lightweight Flywheels offer better acceleration after the clutch has been fully engaged, engagement takes longer, as engine torque used is decreased due to reasons mentioned above. Idle negatively effected, as well as cold weather starting. Shifting is tougher, causes more wear on transmission, difficulty pulling taller gears at lower rpms. Recommended for drag racing and circle track racing applications.
Heavy Flywheels accelerate slower and engagement is faster. Shifting is easier, causes less wear on the transmission. Idle is smoother, cold weather starting is easier. Higher top speed achievable. Really recommended for bigger and heavier tires. Great for 4WD since it makes better use of the torque by keeping the inertia of the engine!