Delco Remy 40SI™ High Output Brushless Alternator

40SI Brushless Alternator
The 40SI™ is a durable brushless model available in output ranging from 240 to 320 Amps. Its efficiency rating is best-in-class.  High efficiency translates to less engine horsepower requirements, resulting in substantial fuel savings. The 40SI is available with three mounting styles allowing flexibility when switching form a competitive model.  The premium brushless design of the Delco Remy 40SI provides added durability and life of the alternator.  Remote sense is standard on all 40SI models.

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Performance Output 12 Volts 240 Amps (160 Amps at idle)
12 Volts 275 Amps (180 Amps at idle)
12 Volts 300 Amps (190 Amps at idle)
12 Volts 320 Amps (190 Amps at idle)
Maximum Speed 8,000 RPM Continuous
10,000 RPM Intermittent
Rotation Clockwise
Temperature Rating 240 & 275 Amp: 125°C / 257°F
300 & 320 Amp: 115°C / 239°F
Mounting J180 Short Hinge
J180 Long Hinge
Polarity Negative Ground
Efficiency 72%
Weight 31.0 lbs / 14.1 kg
Stator Diameter 5.98 in / 152 mm
Length 9.92 in / 252 mm
Remote Sense Standard
*(US /Canada Only)
3 year / unlimited miles


40SI Lineart Short Hinge Dimensions
40SI Pad Dimensions
40SI Lineart Long Hinge Dimensions

Remote Sense

Remote Sense can reduce battery charge time by 50%. Some 35SI models are equipped with Remote Sense which utilizes a second wire that reads the actual to boost its output to compensate for the voltage drop, ensuring 14 Volts at the battery. The proper voltage forces more current into the battery bringing it to a full state of charge between vehicle stops.