Here's a lightweight water pump pulley to reduce rotating mass from your engine. Precision CNC'd from aircraft grade billet aluminum this is a normal diameter spec unit and not underdrive. Installation does not require different length belt, and will not affect aftermarket supercharger installations.
The OEM steel water pump pulley is stamped which creates internal stresses that eventually cause the pulley to crack at the sharp bend radius. Needless to say, you don’t need this problem on a hot running VR. Ours is machined from a solid chunk of aluminum with generous corner radii and is therefore many times stronger than OEM. Weighing in at a scant 250 grams, its less than half the weight of the stamped OEM pulley. Fits ALL Mk2, Mk3 and Mk4 12 Valve VR6 VW engines as well as 3.2L Audi A3, TT, and Q7 and replaces P/N 021-121-031A (021121031A).
