Like Mike said, 10 Volts under 800 RPM with the lights and what ever other accessories you running (like AC or heater) but charging at 14 Volts above 800 actually sounds normal with a 10SI.

I think Mike meant to say go with a smaller alternator pulley to speed up the alternator....the other option would be a larger drive (crankshaft) pulley......or you could just speed the idle up a little if it bothers you.


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