Developed for the track driven Nissan 300ZX Z32 the H.I. Water pump pulley addresses a cooling problem that can surface when you install an Unorthodox Racing, ASP, ATI (street version) or similar sized under drive crank pulley. When you install a smaller then stock sized aluminum CRANK pulley you reduce not only the speed @ which the water pump turns @ a particular RPM but also the speed of the radiator fan. By doing so you doubly reduce your cooling capabilities in the process. This change is not always perceived by the casual driver because the temperature gauge on the Z32 is not linear, it tends to hover around the 8-9 o'clock mark during most street use by design. However the effect of the installing a smaller then stock crank pulley can be seen if you use nProbe/Consult/Hardware or similar data logging software/hardware - temeratures rise across the board but esp. at stop & go idle and at high load / track conditions.
The solution - H.I. has introduced an overdrive pulley for the water pump to be used in conjunction w. a smaller then stock main crank pulley. Their pulley is about 15% smaller then a stock sized Twin Turbo water pump pulley and returns the water pump & fan speed to the same amount of circulation per engine speed as the Nissan engineers intended. On modified or track driven cars that are pushed to their cooling limits this can be answer to maintaining proper cooling system performance and keeping your motor out of the red.
Works on both TwinTurbo & NA models
Light weight & strong T6061 Aluminum
4.4oz. vs. 10.2oz. stock unit
Clear anodized for anti-corrosion.
Includes shorter Nissan drive belt!
Precision made in the USA