Does alternator pulley size matter?

Using a smaller pulley will speed the rotor up, and the alternator will produce more power. This won’t effect the ECM or anything else in the vehicle, since top voltage will still be regulated.

Are all alternator pulleys the same size?

Alternator shaft sizes are not all identical so a pulley from one alternator may not be interchangeable with a pulley from another. These pulleys are also available separately for purchase , typically the cost is $60-100.

What is alternator pulley ratio?

To calculate a vehicle’s pulley ratio, the engine’s crank pulley diameter should be divided by the alternator’s pulley diameter. This ratio should then be multiplied times the highest expected engine rpm. The result will be that vehicle’s maximum alternator rpm. Crank Shaft Pulley Diameter.

Are alternator pulleys interchangeable?

Use the proper alternator pulley type for the specific vehicle: solid pulleys, one-way clutches and overrunning alternator decouplers are not interchangeable. So it is vital that the new alternator pulley is the same type of pulley that was installed by the vehicle manufacturer as original equipment.

How does pulley size affect speed?

If a smaller pulley turns a larger one, the larger one will turn slower, but with more power available at the shaft. If a bigger pulley turns a smaller one, the smaller one will turn much faster than the bigger one but with less power available at the shaft.

How do you measure an alternator pulley?

Place your pulley face down on a flat surface, then put your ruler or caliper on top, measure from outside edge to outside edge across the circle of the pulley. Check carefully to make sure you are measuring across the center.

How do you calculate alternator rpm?

Speed(RPM) = Frequency(Hz) X 120 / Poles = 100 X 120 / 12 = 1000 RPM.

What RPM does a alternator run at?

Typically, alternators have their full output rated at 6000 RPM but can continue to spin up to 12,000 RPM or more without any additional increase in output. The speed of an alternator is different for different type of car.

How do you measure the pulley diameter on a alternator?

Does size of pulley matter?

A larger diameter pulley wheel (aka sheave) is technically more efficient than a smaller diameter pulley. But it’s a trade off: a larger pulley has increased bulk, weight and cost. For example, in a 1:1 haul, you gain about 7% efficiency going from a 1.5” pulley to a 3.75” pulley.

Does a bigger or smaller pulley increase speed?

Pulleys of Different or Same Size If a smaller pulley turns a larger one, the larger one will turn slower, but with more power available at the shaft. If a bigger pulley turns a smaller one, the smaller one will turn much faster than the bigger one but with less power available at the shaft.