amperage question
 

I have a Powermaster 130 amp alt with underdrive pulleys. I'm only generating 12.5 volts @ idle.
Has anyone upgraded the gauge of the supply wire from the alt to the battery?
Any other tips would be appreciated.
If I have to, I'm putting the original crank pulley back on. I've got gobs of power anyway.

thanks

Re: amperage question
 

What is it charging when you run it near 1500 rpm? I think that's pretty good at idle considering the underdrive pulleys. If it was a stock fox alternator you'd be in trouble, lol. What gauge is the supply wire going to the battery?

Re: amperage question
 

i have a PaPerformance 130amp alt w/ March 1000 underdrives. i charge at about 13.5 volts at idle, thats according to my autometer gauges which draws its reading from my ignition switch. I assume if i connected a voltmeter to the battery it might read even higher. at idle w/ the lights on and a/c, the gauge will read around 12.5 volts. i did upgrade the wire from alt to starter relay to 4 gauge as it was recommended by PaPerformance. I also upgraded my battery cables and starter power wires to 4 gauge.

i would try to upgrade your alt wire to starter relay, i doubt the factory wire is large enough to make use of all the power the alt is producing. if you want more juice, change the size of the alt pulley and i would leave the underdrive crank pulley alone.

Re: amperage question
 

Thanks for the advice.
It looks like 8 gauge wire is coming from the alternator.
I'm going to upgrade everything to 4 gauge.
Right now, it's only putting out 12.7 at 1500 rpm on the fluke meter.
If that doesn't do it, I'll go to a smaller pulley too.
thanks again, I'll post results later.

Re: amperage question
 

I'd get a 2 gauge positive cable.

Re: amperage question
 

4 gauge is plenty, which is what I've been using for years now.

Re: amperage question
 

Sit back and read. What you all say is TRUE..... to an extent.
Everything you wanted to know about Alternators, but were afraid to ask.

Re: amperage question
 

Jester,

Good read, lots of information.

Thanks,

Re: amperage question
 

that's a great article. seems like there's more electrical work to be done now.
I just read how the powermaster doesn't like to spin more than 20k rpm..I'm not sure mounting a smaller pulley is the only thing to do after upgrading to 6 gauge.
going to look into this relay thing some more...thanks again

Re: amperage question
 

Tried to give you a wire size vs amp rating for under the hood but the image problem is still here - doesn't recognize jpg as a "valid" file - even though it is.......