I dunno where the thread went that I posted earlier but here it is again...

It rained like a **** on Friday here in the D/FW area...monsoon like, type of stuff you'd see in the jungles of Vietnam! Streets flooded and stuff!

1. So since it was cooling off rapidly with the rain, I flipped my A/C onto defrost so I could see. My fans kicked on at low speed and the blower was at No 2 (of 5) on the speed. Still over 14v on the gauge.

2. Flip the head lights on and the fogs to see...it was dark afterall. Still over 14v, barely.

3. Auto 4wd was on also if that makes a difference or not.

4. Radio comes on next...multi amp, multi component, single woofer setup. Pretty tame level, enough to have a coherent conversation with. Save as above, still over 14v. I do have a 1 farad cap and an Optima Yellow top.

5. The occasional cleansing of the window with the wipers too.

6. Lastly I turned on my rear defroster as it was fogged up too...this also heats my side mirrors... then whamm-o (like the frisbee makers ) south of 14v. That put it over the edge.

So that should give ya an idea what it takes to make the Delco 130A unit not keep up at idle speeds. I also have ***-warmers (don't need them as it's not cold out now) in the seats so those also could hurt the alt's charging at idle.

The OE 130A unit puts out ~55A at idle I read somewhere, so if I can put a pinch on it w/ most everything on and the stereo down low...a 160-200A may be a better option for some of you guys out there with big electrical loads. I may get an ASP OD alt pulley here to see how much that helps...

 

what is a stockers ratings?

 

It will say the stock amp size on the side of the alt. Its either a 105 or a 130A(mostly found on HD's or Denali/Esky). Nice write up Hit. I still think I am going to go with the 200. I will have an od pulley for the altenator for sale after that. Its the only thing I have left to buy to finish my mods. Just tooo many priorities right now.

 

All the 1/2 tons pretty much come with a 105A unit. The OE 130A box outputs ~22% more amperage I guess from my math (hey I passed my Calc classes and can't tell you anything I learned in them! ) so if that's true...

Take 55A of the 130A puts out a idle, that gives you around 42A at idle for the 105A box. 13A idle gain is pretty good considering the $100 price tag. The OE 130A box WILL REQUIRE a longer belt. It's like a 930 length I think it was.

Is the OD pulley you have the ~1.75" one? If so I'd prolly take it off your hands...

Also, when you look for a 200A unit...make sure it doesn't output higher amperage in the RPM range, not at idle. I made that mistake with the 200A unit on my F150 and it puts out LESS at idle than my 3G 130A Ford unit did at idle! It was so low I was forced to remove my ASP pulleys!

Typical output on a good 200A unit should be 90-105A at idle w/ ~3:1 alt ratio. Alt ratio is taking the crank pulley diameter divided by the alt pulley diameter... 6" crank / 2" alt = 3:1 ratio, about perfect for the street. You could drop into the 2.5-2.6:1 area but idle charge will suffer accordingly. If you do a 25% under crank pulley with that OD alt pulley it'd be something like... 4.5" crank / 1.75" alt = 2.6:1 so yo'u'd be down to ~67-77A at idle.

Phew, that's a lot of odd info you'd be hard pressed to find!

 

Its whatever the overdrive pulleys are. A alt is gonna be tight right now. More money needing to go out then coming in, ya know.. I will let you know though.

 

Yeah that's cool, just keep me posted.