Flywheel
for your 1987 BMW 325
Located at the rear of the engine and bolted to the crankshaft is the flywheel. Only found in manual transmission components, this piece is what creates the friction needed to engage the clutch pressure plate and the clutch disk. This part gives your BMW 325 starter more leverage against the engine.
In a manual BMW 325, the flywheel is either considered a light or heavy construction. If it is lightweight, the engine can rev faster and get a quicker start off the racing line. Heavy components are not quick but can keep the RPMs of the engine more consistent when engaging the clutch.