Top Tips

Top Tips

10 Top Tips for choosing an Alternator

  1. Calculate the maximum output in Amps that you require either by totalling the power requirement of all your electrical ancillaries or by measuring the total Amps drawn by the Battery with an Ammeter.

  2. Calculate the maximum speed that the Alternator will run at full engine RPM, the maximum rotor RPM of Brise Alternators is 18k RPM. To calculate the pulley drive ratio, divide the diameter of the crankshaft pulley by the diameter of the Alternator pulley, then multiply this ratio by the maximum engine RPM.

  3. Remember that the output of any Alternator is dependent on rotor speed, the output quoted for all Brise Alternators is the maximum test value at about 6000 RPM rotor speed, which normally equates to about 3000 RPM engine speed with a 2:1 pulley drive ratio. Our test values are acquired at a charging voltage of 13.5 volts min. and in Hot condition.

  4. Brise uprated Alternators ( anything with suffix S to the part number) are modified to give much higher output at high engine speeds i.e. Track or Rally Conditions, but not at low engine speeds or at tickover. Check the output graphs available from the website to ensure adequate output if you intend to use one of these Alternators on a car that is likely to travel on public roads. It may be necessary to increase rotor RPM (max.18K) using a smaller pulley in order to gain the maximum benefit from uprated Brise Alternators.

  5. Heat and vibration are the biggest enemies of an Alternator, ensure  that the Alternator will receive adequate cooling air, especially ‘S’ type. If mounted close to a heat source such as exhaust or turbo, use heat shields and / or forced air cooling directed at either the rear cover or the pulley, not at the radial slots in the casing (air is designed to exit from these slots).  

  6. Alternator mountings should be designed for the minimum of flexing to reduce vibration, if anti-vibration bushes are used, they should be a hard PU type and not rubber. If possible choose an Alternator with more than one mounting point (not including the tensioning arm). Do not use a painted or anodised mounting unless a separate earth connection is provided.

  7. Brise Alternators are based on Denso, Mitsubishi, or Delco units with modifications and improvements specific to Brise, any of these types are suitable for Motorsport applications, choosing which type suits you is a matter of which has the optimum specification, size and mounting pattern.

  8. Brise alternators are supplied with a standard steel pulley included in the price, if you require a specific diameter or belt type of pulley please enquire if a steel type to suit you can be included. If it is not available in steel, we have many types of Aluminium pulley available at extra cost

  9. Consider if you will need an electrical connector harness or plug to suit your vehicle wiring. Connectors are available from Brise website but not included in Alternator price.

  10. If there is not a suitable Alternator on Brise website, please submit details of your requirement and we will try to offer a solution. Brise are experienced in producing special adaptations of Alternators for many different applications and can also supply a large range of standard road car Alternators.

Contact Brise for more information.

 
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