How much alternator needed?

i just posted this in another thread. I think it still pertains to you as well.

my battery just started dying within the last 2 weeks. i couldnt figure out why. i replaced the battery and it still started draining. i took it around the corner and they told me the alt worked sometimes and sometimes it didnt. cost me 15.00 to find out for sure the alt either had a short or was going bad.

I called pep boys and oreilys for a 94-95 gt 130a alt. they wanted between 119.00 with a 35.00 core and 139.99 with a 20.00 core. I posted on my local club site and one of my buddies on there told me he just swapped out his for a 130 and the 96 up v6's are all the same 130s that the 94-95 gt used. he gave me the name of the name of the salvage yard he used and sure enough they had 3. I got a 2000 v6 130a alt. for 35.00 with a 10.00 core and a 91 day warranty. not bad at all. I had to get the plug with it and solder that plug on.

I figured why do a stock 75 again when I can get a 130 now. it wasnt a big deal at all. the slight grinding of the bracket was the worst simply because i only bought a grind bit and not a drimel. a drimel would have taken about 10 minutes i would guess and having done just a bit on my drill i would say get the drimel. lol

if you decide to do the 130 email or pm me and ill show you where I got the instructions with step by steps. just make sure you get the plug with it or you will have to make your own.

Keep in mind that even if you go with a 3G alt. it will still only put out X number of amps at idle due to the underdrive pulleys. Higher output alts typically use smaller pulleys. If you use an alt underdrive, you are defeating the purpose of using a higher output alt. An alt. must run at a 3:1 alt/crank pulley ratio. In other words, the alt spins 3 times the speed of the motor. Underdrives change this ratio. A 3G alt will put out a little more amperage than your stock unit, but will not run at peak efficiency until you're at cruising speeds.

definitely 3g alt with smaller pully

Don't forget to upgrade the wiring when you put on the higher amp alternator.

The stock wiring is barely capable of handling the stock alternator's maximum output. If you put on a high-output alternator without upgrading the alternator-to-battery wiring, you're just asking for a fire.

I make a 4-gauge fine-stranded power wire with inline fuse specifically for alt. upgrades. Let me know if you need one.

sweet 95BLB, how much, I am about to upgrade myself

TRWXXA said:

Don't forget to upgrade the wiring when you put on the higher amp alternator.

The stock wiring is barely capable of handling the stock alternator's maximum output. If you put on a high-output alternator without upgrading the alternator-to-battery wiring, you're just asking for a fire.

Click to expand...

Good call! I used 4 guauge wire from the alternator to the starter solenoid (Battery side) to replace the factory wire. Also got my alternator from Autozone for the 94-95 for $109.00 with a lifetime warranty. I also changed the pulley for an overdrive alternator pulley from Summit for $18.50 part number ASP-520004.

You'll need a power wire upgrade like this or similar to it: