amperage question

Hozer 88GTConv · 09-01-2005, 03:20 PM

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

Ieatcamaros · 09-02-2005, 03:26 AM

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?

GhettoPop · 09-02-2005, 08:39 AM

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.

Hozer 88GTConv · 09-02-2005, 01:50 PM

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.

Ieatcamaros · 09-04-2005, 08:03 AM

I'd get a 2 gauge positive cable.

82 GT · 09-04-2005, 12:43 PM

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

~The Jester~ · 09-05-2005, 05:31 PM

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.

Gearhead999 · 09-05-2005, 08:25 PM

Jester,

Good read, lots of information.

Thanks,

Hozer 88GTConv · 09-05-2005, 08:36 PM

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

tmoss · 09-06-2005, 07:59 AM

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.......

09-01-2005, 03:20 PM	#1
Hozer 88GTConv Registered Member Join Date: Feb 2002 Location: Jacksonville, FL Posts: 706	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 __________________ 1988 GT Convertible 331 10:1 TW heads, GT-40 intake, MSD, TRW flattops, B Cam w/ 1.7's, MAC exhaust, 24's, 70 TB, 76 MAF, 3.73's, Pro 5.0, Koni's, Anderson PMS, Wideband 02, yatta, yatta... One week with new motor, two speeding tickets...joy

09-02-2005, 03:26 AM	#2
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	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? __________________ The sig says it all.

09-02-2005, 08:39 AM	#3
GhettoPop Gimme a Drink! Join Date: Dec 2002 Location: NYC Posts: 694	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. __________________ 1990 GT,stock T-5,K&N w/o air silencer,March underdrives,FMS wires,timing@14*,PA Perf 130amp alt,Steeda Tri-Ax Shifter,Steeda adj quadrant/clutch cable/firewall adj,Centerforce II clutch,o/r x-pipe,Magnaflow SS catback,g-load brace, subframes,Bilstein struts/shocks,Autometer gauges, 136k and running strong!

09-02-2005, 01:50 PM	#4
Hozer 88GTConv Registered Member Join Date: Feb 2002 Location: Jacksonville, FL Posts: 706	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. __________________ 1988 GT Convertible 331 10:1 TW heads, GT-40 intake, MSD, TRW flattops, B Cam w/ 1.7's, MAC exhaust, 24's, 70 TB, 76 MAF, 3.73's, Pro 5.0, Koni's, Anderson PMS, Wideband 02, yatta, yatta... One week with new motor, two speeding tickets...joy

09-04-2005, 08:03 AM	#5
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	Re: amperage question I'd get a 2 gauge positive cable. __________________ The sig says it all.

09-04-2005, 12:43 PM	#6
82 GT Import Slayer Join Date: May 1999 Posts: 2,241	Re: amperage question 4 gauge is plenty, which is what I've been using for years now. __________________ '82 GT 351W (.060)Comp Cams 274* Extreme Energy cam, ported & polished heads w/ 1.94/1.60 valves 10.3:1 flat top pistons,stealth intake, Mallory dizzy,Holley 750dp carb, BBK shorties,Flowmaster exhaust,C-4 with 3700 stall converter, B&M pro shifter,8.8 rear, 4:10's, subframes, electric fan, powermaster alternator, 4 core radiator.

09-05-2005, 05:31 PM	#7
~The Jester~ Rat Killer Join Date: Aug 2002 Location: Cold ass Ohio Posts: 1,143	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. __________________ d-Con Racing "Nothing fancy, just 347 inches of RAT POISON!" MICE need not apply.....

09-05-2005, 08:25 PM	#8
Gearhead999 Registered Member Join Date: Sep 1998 Location: Oviedo, FL Posts: 992	Re: amperage question Jester, Good read, lots of information. Thanks, __________________ "Support our Troops" Dave 1968 Cougar 2004 Thunderbird 2007 F150 Harley-Davidson, SuperCrew 1986 LTD 1997 Ranger 1992 Honda Civic

09-05-2005, 08:36 PM	#9
Hozer 88GTConv Registered Member Join Date: Feb 2002 Location: Jacksonville, FL Posts: 706	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 __________________ 1988 GT Convertible 331 10:1 TW heads, GT-40 intake, MSD, TRW flattops, B Cam w/ 1.7's, MAC exhaust, 24's, 70 TB, 76 MAF, 3.73's, Pro 5.0, Koni's, Anderson PMS, Wideband 02, yatta, yatta... One week with new motor, two speeding tickets...joy

09-06-2005, 07:59 AM	#10
tmoss Registered Member Join Date: Mar 2003 Location: Saint Louis, MO Posts: 634	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....... __________________ Tom (Torque) Moss 88Gt 5spd Vert, FLowmaster Catbacks, stock cam advanced 4° @ 108.5° ICL, NMRA prepped GT40P heads 1.85/1.55 valves and 1.7 rockers, MAC P headers Jet-Hot coated, 97 Exlporer intake (ported lower), TB and injectors. 277RWHP/330RWTQ (SAE). http://www.fastlanecars.com/

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Another tire question	96Saleen	Modular Madness	6	02-10-2004 05:27 PM
A stupid question I hate asking about exhaust sound	jwboner	Windsor Power	4	08-05-2003 05:55 PM
simple question	Lonzo	Classic Mustangs	3	09-10-2002 09:37 AM
Newby here, I have a question on Odometers	mustangmama	Blue Oval Lounge	3	03-03-2001 06:43 AM