Alternator questions

TrickStang37

New Member

Oct 17, 2004

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Apr 12, 2006

#1

• Apr 12, 2006

• #1

I have a 100 amp Powermaster alternator and want to know if you guys think that will be enough to power an electric fan, electric water pump, and a smaller electric fan for my oil/tranny cooler and POSSIBLY electric fuel pump in the future. Im not gonna be running a high power stereo or anything like that. I use to run a 3G alt in my 5.0 (160amp) and that thing wouldn't blink no matter what I threw at it but Im not sure about this alt. It looks really nice, all chrome, and goes for $170 on summit so i'd prefer if i could keep it. The car will not be running for a few months so just looking for opinions.

 

iskwezm

10 Year Member

May 24, 2005

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Rowland Heights,California

Apr 12, 2006

#2

• Apr 12, 2006

• #2

I have a 100 amp and run 2 fans,fuel pump and 1400 watt stereo, its rewound so its not as "strong" as a powermaster,but it does good

 

Tim65GT

Active Member

Feb 24, 2004

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West Texas

Apr 12, 2006

#3

• Apr 12, 2006

• #3

I'd go with it since it's something you already have.

Even though it's rated at 100 Amps, the output at idle is also important for a street car. Once you get it running, check the battery voltage with all accessories on and see what ya get. If it's less than 13 volts, try to up the idle to see if you can live with it. If not, go back to a 3G

 

TrickStang37

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Oct 17, 2004

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Apr 12, 2006

#4

• Apr 12, 2006

• #4

how bad, if at all, would it be to overdrive the powermaster alternator? On my 5.0 with the 3G I over drove the alternator since I was running underdrives on the crank and water pump (no powersteering or smog pump). either way, i will definately not be running underdrives with this alt/crank since the alternator will be the only accessory i will be running.

 

Tim65GT

Active Member

Feb 24, 2004

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West Texas

Apr 12, 2006

#5

• Apr 12, 2006

• #5

I don't know about the powermaster, but the 3G I have already came with a pretty small diameter pulley. (It's from a '94 GT) I swapped to a double V-groove because it slipped on startup with just one belt. Seems if you go smaller to overdrive it, you'd have a hard time trying to keep it from slipping.

 

TrickStang37

New Member

Oct 17, 2004

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Apr 12, 2006

#6

• Apr 12, 2006

• #6

on my 3G i had problems at first with it slipping, but that was when there was a load on the electrical system (electric fan) and the tensioiner wasn't able to hold the belt tight enough. with a better tensioner i had no problems.

when i ran the 3G i used a smaller than stock size pulley by buying a pulley usually used on limo's. i didn't have any problems, but anyone know if overdriving (smallest possible pulley) an alternator is a bad idea?

 

TrickStang37

New Member

Oct 17, 2004

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Apr 13, 2006

#7

• Apr 13, 2006

• #7

ttt

 

F

ForceFed70

That's why they call it "dope"

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Dec 6, 1999

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BC Canada

Apr 13, 2006

#8

• Apr 13, 2006

• #8

Only problem with overdriving the alternator is that the bearings will wear out sooner. Especially if there is alot of heat.

Personally, I think you'll be fine. I wouldn't bother swapping pullies until you've actually seen a problem.

 

65ShelbyClone

Founding Member

Sep 9, 2000

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Antelope Valley, SoCal

Apr 14, 2006

#9

• Apr 14, 2006

• #9

Is this going to be mostly a drag car? If not, then I would forget both electric pumps. If you do that, the 100A should be fine running just the two fans and chassis electrical. Many mechanical fuel pumps can supply 500hp or more. Electrics are usually quite loud as well. My Holley Red is loud inside and out. When it burns up I'm going back to mechanical.