7 replies to this topic

[Deanorch1978]

Hi can someone help me? I'm looking for a hire output alternator for my 1293cc. I'm thinking about a mpi one can I do this? Or is there a better one of any other car that I can use?

[HarrysMini]

The MPi alternator uses a poly-v belt which you won't be able to use with your fan pulley. 

 

Use a 70 amp uprated one from Minispares, they are good.

[alex-95]

Yep like above the mpi one has a different belt

heres the 70 amp

http://www.minispare...|Back to search

[Deanorch1978]

Thank you is there any smaller ones to the stander size ones that I can uses? But higher in output 70amp?

[jacobtomos]

MED do a smaller one (http://www.med-engin...ight-alternator) but it's not higher output. Pricey too...

[Guess-Works.com]

Why do you need a higher output alternator ?

 

The alternator will only output what you need, so if you need 20amps, then a 45amp alternator will deliver exactly the same as a 70amp alternator...

 

And...

 

If you do need 70amps worth of charge then I hope you have upgraded all the wires in your loom to accommodate the extra current draw. 

 

70amps equates to almost 1kw if using the 13.8 charging voltage as a multiplier.

[Cooperman]

You should do a 'power loading chart' by adding up all of the electrical services which can be switched on at the same time. This will be in watts.

So, for example, the headlights will be 2 x 55 watts = 110 watts.

Then add the heater blower, the sidelights, the instrument lights, rear lights, heated rear screen, spotlights (if fitted), audio system and rear fog light.

 

Take that wattage maximum and divide it by 12 to get the amps. Add 10% for a reserve factor and that is the alternator you need.

[Deanorch1978]

jacobtomos that alternator will be very much like mpi one with the v belt pulley. So I wouldn't be using that one. Thank you. Ok 70amp alternator will have to do.