Answer
Nov 11, 2024 - 07:18 AM
You may have to adjust the tachometer reading. The way they get increased power from these alternators is by putting more poles in them which increases the frequency of the output which makes the tachometer read higher.
To calculate likely output at a particular engine speed you have to check your pulley ratio to figure out how fast the alternator is turning. A typical pulley ratio is 2:1 so if the engine was turning at 1000 RPM the alternator would be turning at 2000 RPM. Then you can consult the manufacturer's output curves. In the graph below you can see that the alternator is only getting started at 2000 RPM. When the alternator is hot it can produce 70 amps at 2000 alternator RPM. For better low RPM performance you would be better off with an XT alternator.
To calculate likely output at a particular engine speed you have to check your pulley ratio to figure out how fast the alternator is turning. A typical pulley ratio is 2:1 so if the engine was turning at 1000 RPM the alternator would be turning at 2000 RPM. Then you can consult the manufacturer's output curves. In the graph below you can see that the alternator is only getting started at 2000 RPM. When the alternator is hot it can produce 70 amps at 2000 alternator RPM. For better low RPM performance you would be better off with an XT alternator.
