[george kujanski]

Here are the specs for the Delco 12SI 94A. As you can see, full rated output is 94 A, slightly over 5000 shaft RPM. This is typical for alternators.....the output maxes out in that range. At 2000 shaft RPM you get about 50A, which will correspond to about 1000 engine RPM if your pulley ratio is 1:2. (alt =1/2 the size of the crank pulley)

With a larger pulley ratio, you will get more output at the same engine RPM; the output curve is fairly steep in that range, so a small change in engine RPM or pulley ratio will make a big difference.

The curve is usually done at 14.0 volts out, alternator temperature stabilized. I don't recall what ambient temperature is used, but the important thing is the output will increase if the air temp is cooler and therefore the alt temp is also less.

The test conditions probably are similar to underhood operation with A/C on, running for an extended length of time so the alt temp has stabilized.

When comparing output ratings, the temperature conditions should be known, since an alt can output substantially more current when the machine is not stabilized at normal operating temp.

George