3G just installed....
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So it seems that the remanufactured 3g alts arent up to par and are marginally better at best than the 2G alts. Thats info I wish I had before doing this swap as it would have saved me a lot of time/money and headache. Don't buy a refurbrished 3g is the moral of the story
I don't think it's been done because swapping pulleys is a band-aid, as many folks (myself included) dont have to do it. Each combo is different. Some of the write-ups (M. Smith's comes to mind) do note pulley swapping, with part numbers and diameters. That link comes up in any alt search.
Heres's the link HISSIN50 was talking about...
See http://www.geocities.com/smithmonte/Auto/3G_130A_Alternator_Upgrade.htm - all the tech data you could ever want to know about 3G alternators.
91green5.0
New Member
Ive been thinking about switching to a 3G in the spring because me stereo is way to big for the stock alternator. I think its about 1200 watts. Would a stock 3G be big enough because i dont know alot about alternators? I want to make sure i have plenty of power so if i run the A/C with the lights on and stereo going my lights dont dim and get brighter going down the road! 
Ive been thinking about switching to a 3G in the spring because me stereo is way to big for the stock alternator. I think its about 1200 watts. Would a stock 3G be big enough because i dont know alot about alternators? I want to make sure i have plenty of power so if i run the A/C with the lights on and stereo going my lights dont dim and get brighter going down the road!
Do the math: volts multiplied by amps = Watts
14 volts x 130 amps = 1820 watts.
1830-1200 = 630 watts
630 watts divided by 14 volts = 45 amps.
You have 45 amps to run the rest of the car's elecrical system.
Figure this:
Ignition system & computer = 12 amps
Fuel pump = 12 amps
Exterior lights = 15 amps
Fan (heater or A/C) = 15 amps (can run between 5-25 amps depending on setting)
Radio & instruments = 10 amps
Wipers = 10 amps
That's grand total of 74 amps.
I'll let you subtract the 45 from the 74 and see how short you come up...
Keep in mind that alternators produce max power at speeds in the cruse RPM range of 1700 RPM and higher. Cars with underdrive pulleys will need to turn more RPM's to produce the same output as a similar car without underdrive pulleys.
Not necessarily.
I usually recommend the O/D alt pulley to people running U/D crank pulleys.
I ran the numbers a long time ago and determined that that combo usually equals an alt speed at idle roughly equal to what it would be if every pulley was stock.
I think i based the math off my own March pulleys.
bloopbloob
Member
Ive been thinking about switching to a 3G in the spring because me stereo is way to big for the stock alternator. I think its about 1200 watts. Would a stock 3G be big enough because i dont know alot about alternators? I want to make sure i have plenty of power so if i run the A/C with the lights on and stereo going my lights dont dim and get brighter going down the road!
i used to run 4x12" JL subs (with a capacitor), and high end infinity speakers all around off of 2x1000W digital Alpine amps in my car a couple years ago on the stock alt. It wasn't ideal, got a few dead batteries and lights always dimmed to the bass hits, but it handled it fairly well i guess. from my experience with the 3g i have now, i think it could handle it, even though i ditched that stereo once i grew up! It's FAR superior to the stock alt.
91green5.0
New Member
Yeah im running a capacitor also and Im thinking about maybe getting a bigger one. I figured it would have to be better than stock! 4 12s must have been a tight fit. Mines got 2 jl10w6s. I wouldnt have spent that much but I bought it that way.
bloopbloob
Member
it wasn't that bad actually. i had 2 facing straight forward, and then the 2 you can see in the pic here.
91green5.0
New Member
Yeah thats pretty big. I had 2 of those in my 89 and it wasnt too bad but 4 must have sounded good. Looks like your cars white with red interior, thats my favorite color combo. Looks like your running alot of the mods i want to run too!
I'm running a parts store reman 3G (Autolite brand from Shucks) listed for a '95 GT. Swapped the huge pulley it came with for my 2G pulley and added an additional 4G ground wire. I'm not running underdrives and I have yet to install my Taurus fan, but at idle with all acessories on the volt gauge doesn't budge, I have no dimming of any lights, and my windows roll up and down faster than they ever did with my old 2G alt. I've been driving the car all winter and even with the heater, rear defrost, headlights, and wipers running all at once every day it's been working fine. I also have an aftermarket stereo that puts out about 500 watts, and even with the music turned up it doesn't seem to tax the alt.
I'd say either you got a bad alt, or maybe you have a weak ground someplace. I bought 10ft of 4 gauge cable and replaced all of my stock grounds as one of the cables was coming loose in it's ring terminal and they were all looking pretty ratty anyway. I bought solid copper ring terminals from Lowes and soldered them to the cable ends. They look good and should last for years.
I'd say either you got a bad alt, or maybe you have a weak ground someplace. I bought 10ft of 4 gauge cable and replaced all of my stock grounds as one of the cables was coming loose in it's ring terminal and they were all looking pretty ratty anyway. I bought solid copper ring terminals from Lowes and soldered them to the cable ends. They look good and should last for years.
