I replaced my alternator and water pump pulleys with
the Greddy Pulley kit. This modification is a more controversial
one, as it may not apply to weekend warriors. There are
several purposes to the kit:
The positive reasons for this upgrade are: cleaner engine
bay, less load on engine when accelerating (slightly noticeable), possible
reduction of cavitation from water pump (Basically if the water pump is
slapping air bubbles around instead of pumping coolant)
The negative reasons for this upgrade are: Alternator
running at lower RPMs (not a substantial difference but may affect large
sound systems), cost versus actual performance increase is minimal
I chose to spice up my engine bay and install the pulleys.
I really wanted to remove my air pump as I had disconnected it a while back.
I was able to see my first turbo after removing the air pump. I am
keeping all of the old parts in case of emissions. My engine bay looks
sharper after the upgrade. I also did notice a lower fuel consumption
at idle. It was extremely small but the PowerFC caught it. ( I
used to idle at approx 3.8% inj duty, now it is 3.6%)
I felt a smoother shift into first gear but this may be due
to unknown factors.