The speed of the damper vs pump is not belt width, the diameters are different.
The late water pump has far more capacity than the early pump. Its rated output is 14.5 GPM (gallons per minute) per 1,000 pump RPM, 72% higher than the early pump at 8.4 GPM. In use, the water delivery rates are more similar because the early pump turns faster due to its pulley sizes.
