Increase Alternator Output and Cooling with Pulley Size

Pulleys shown, L-R: 2-3/8" diameter,   2-1/4",   2", and 1-7/8"
Yes, you can increase your alternators overall output as well as increase power output at engine idle speeds. 
Check the size of the pulley on your alternator. If you are having problems with overall alternator output or charging at engine idle,  maybe a smaller pulley is all you need. The most common pulleys on GM, Ford and Daimlier/Chrysler vehicles are the 6-groove 2-7/16, 2-3/8 and 2-1/4 inch pulleys, by reducing the pulley size to 2" or 1-7/8" your alternator will start producing power sooner and produce more power cruising down the boulevard or on the highway. Also, because your alternator is spinning faster the fan will move more cooling air through the alternator adding to component life. 
Caution must be noted: Changing the pulley size on your alternator may void the manufacturers warranty. Faster spinning alternator will increase brush wear and using a smaller pulley on a high revving engines can cause component failure from extreme speeds. 

 

Buy Button - Price         Our No.               OEM No.                   Description            

Pulleys

..........241250..........1989104...............Pulley 6-Groove 2-7/16"
..........241252..........1989030...............Pulley 4-Groove 2-1/4"
..........241253..........1987648...............Pulley 4-Groove 2"
..........2412553..........1985964..............Pulley 6-Groove 2-1/4"
..........241257..........10495231..............Pulley 5-Groove
..........241263................................Pulley 6-Groove 2"
..........2422521...............................Pulley 6-Groove 1-7/8"

Upgrade to the larger CS-144 series alternator. The CS-144 produces more power at idle and is much more reliable.
cs130 to cs144 comparison

Here we show the CS-130 alternator (left) next to a version of the CS-144 (right) that will fit directly in place of your existing alternator on many 1990-1995 GM vehicles. We have different versions and mounting configurations for other year, model and engine GM vehicles.