This pulley is precision machined to exacting tolerances.
The stock pulley is 3.0" in diameter, and our upgraded pulley is 2.825." Depending on ambient conditions and other modifications, this pulley will produce approximately 1.5-2 PSI of additional boost.
TRD's new supercharger did prove a little tough to design a properly fitting smaller pulley. It appeared that the way the belt drive and snout of the supercharger was designed, some effort was made to make it difficult to fit an aftermarket pulley to it. After several test fittings we were able to produce a pulley that did not require any modification to the supercharger nose or belt drive.
This supercharger uses a press fit design and will require a special tool to install the pulley onto the supercharger input shaft. There are many different tools on the market for installing press fit pulleys that are expensive. URD has a press fit tool available at a great value if you don't have a press fit tool.
Many of Underdog Racing Development's pulleys are not stock replacement pulleys. They are smaller pulleys. URD recommends using all pulleys with proper engine management modifications. Tuning is recommended, and water/methanol injection will lower intake charge temperatures.