Alternator Recommendation

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GoFish

GoFish

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I need some alternator help.

I'm building my Scamp with lots of modern ammenities: AC, power windows, good stereo, efi, electric fuel and water pumps, etc. I know that I'll need a more powerful alternator than the stock 60 amp job. Here are my questions:

1. How big do I need to go? I think 90 amp will still be too small, so I was thinking of 120 amp. Comments?

2. What's the general consensus on 1-wire alternators?

3. I know its blasphemy, but has anyone tried a GM or GM-style aftermarket alternator? Lots more choices, including smaller and lighter. Of course, custom brackets would be required.

Thoughts and questions are welcome.
 
I have been contemplating the same issue(s).

First, you should be able to calculate how many AMP's your combined equip (include headlights, blower motor, horn, etc...) will pull and add 20% to get a reasonable idea of the size you might want.

Next, the wiring must be up to snuff to handle high loads, including proper fused circuits and fusible links where needed.

The ONE-WIRE concept is somewhat misunderstood from what I can see. One wire usually means that the alternator has an internal voltage regulator. The regulator keeps the alternator providing the 14.x volts as required. The problem with them are that most styles get their voltage reading at the alternator output location. Long primary wire runs and bad wiring/corroded connectors (and weak ammeter gauges) all conspire to drop line voltage and you may well end up with 12.5 volts at the actual powered component which can really affect the performance of the component.

Fortunatley there are ways to wire "some" of these (GM models esp) so that they get their voltage "reading" at the end of the feed wired run and where the remote devices tap from so the regulator can more correctly supply true 14.4v. Check out the tech articles at www.madelectrical.com/ for their reasoning and reccomendations... they have some great tech articles to explain this all in general.

I think I am leaning towards the Powermaster PWM-8-57529 140amp alt, wired with the kit from MAD to allow remote field sensing. The issue for me is I have eddy aluminum heads and an electric WP so may have to fab my own brackets. There are also some threads on here with links to a company that makes brackets for other GM and Nippo alt's.

The bottom line is most of our cars are not designed with 80+ amp alternators in mind and some creative wiring, bracketing, and attention to saftey-devices within the circuits is required to get it right. Good luck.
 
I have been thinking of going to a 1 wire alternator (Powermaster 140) also, as I think my 100amp might not be enough. I have added 20amp cooling fans and a 1200w amp and subwoofer.

A one wire is OK to use, I would just be sure to use a good wire to get back to the battery. 4awg welding cable works nicely. It is also a good idea to elimnate the current gauge and go direct to the battery. I made the mistake of connecting my 100amp alternator to the factory amp gauge and quickly let out the magic smoke.
 
Just got to the junkyard if you ask me.

I've been running a 90amp $15 alternator for 2 years now. No problems, factory brackets as well. They also had 120amp models on later cars as well with more options. However I would recommend finding a smaller pulley for it if possible to help keep the amps up at low idle speeds...

http://www.goodysgotacuda.com/DensoUpgrade.html

Google "mad electrical" for their take on 'one-wire' alternators..
 
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