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jmt0645
Tue, June 14th, 2011, 01:11 PM
i got to thinking today (:evillol:) since our alternators are pcm controlled, can the voltage be adjusted within a tune?:shrug:

Jackpine
Tue, June 14th, 2011, 01:49 PM
i got to thinking today (:evillol:) since our alternators are pcm controlled, can the voltage be adjusted within a tune?:shrug:

Are you sure the voltage is PCM controlled? I thought it was just PCM monitored. If it is controlled that way, Bill would have to answer your question. It might be something he could set, but I don't really see an advantage in doing so.

- Jack

cleatus12r
Tue, June 14th, 2011, 01:51 PM
I THINK the later 6.0L trucks can but I have seen nothing in the way of gasoline trucks that supports that idea.

jmt0645
Tue, June 14th, 2011, 02:33 PM
Are you sure the voltage is PCM controlled?.

- Jack
everything i've read suggests the PCM actually supplies the field current for the rotor through the regulator, that the regulator itself is merely a "potentiometer" that is turned by the PCM, thats what got me wondering:shrug:. the reason i ask is i'd like more charging current for my battery bank for the stereo.

Longshot270
Tue, June 14th, 2011, 02:40 PM
The alternator can only work so hard without burning up. You could either run the risk of overcharge or having parts burn up. If your current alternator isn't cutting it then you'll need to go bigger mechanically. If you are having trouble at idle you could try to raise the idle speed. Kinda like I can program my truck to rev all the way to 10K, but the mechanics might not survive.

Jackpine
Tue, June 14th, 2011, 02:44 PM
everything i've read suggests the PCM actually supplies the field current for the rotor through the regulator, that the regulator itself is merely a "potentiometer" that is turned by the PCM, thats what got me wondering:shrug:. the reason i ask is i'd like more charging current for my battery bank for the stereo.

Thanks, that makes sense (how it's controlled), but I agree with Longshot here. If your current alternator isn't up to the task, I'd see about a 200 Amp one.

- Jack

jmt0645
Tue, June 14th, 2011, 02:55 PM
I already have a 250 amp mechman alt but the PCM limits it to 14 volts. I was only looking to go to about 14.5 volts

Longshot270
Tue, June 14th, 2011, 02:59 PM
Is the pulley the same size? My truck will let it go up to mid 14s while driving. Upper 13s while idling.

Jackpine
Tue, June 14th, 2011, 03:26 PM
I already have a 250 amp mechman alt but the PCM limits it to 14 volts. I was only looking to go to about 14.5 volts

OK, I don't really think 14.5V is a good idea. 14.0V means your battery is fully charged, or you would be reading something lower. I think 14.5 would try to overcharge the battery, and that, of course would hurt it. A 14.0 Volt output also tells me your alternator is fully up to the task.

Finally, your electronics might start to suffer at 14.5 Volts.

To see if your battery is charged, you need to have an Ammeter in series on one of the battery cables. If the Ammeter reads near zero, it means it is not accepting a further charge because it's fully charged. At a resting state, disconnected, and with the surface charge from charging worn off, the battery should show about 12.7 no-load Volts if it's fully charged.

- Jack

Longshot270
Tue, June 14th, 2011, 03:33 PM
What are the amps on your battery then? That might be your weak point. If you feel that the stereo isn't hitting hard enough what gauge wire are you using? Also do you have any capacitors wired in?

jmt0645
Tue, June 14th, 2011, 11:13 PM
Sorry guys I've been at work. Wiring is 2 runs of 0awg to the rear batteries with big 4 done in 0awg. Don't have an amp meter but batteries read 12.6 volts. I have duralast starting battery and 2 autocraft deep cycle secondary. I was mainly just curious if it could be done.

jmt0645
Tue, June 14th, 2011, 11:16 PM
Also have 2 10 farad caps wired in, 1 for each amp

jmt0645
Wed, June 15th, 2011, 10:55 AM
Is the pulley the same size? My truck will let it go up to mid 14s while driving. Upper 13s while idling.

don't you have 4.6L? i think its just the 5.4L thats PCM controlled.

Longshot270
Wed, June 15th, 2011, 11:11 AM
don't you have 4.6L? i think its just the 5.4L thats PCM controlled.

Oh, yeah, that could be the possible difference.

I'm planning on a much smaller scale version myself. I've got a 400 amp Harley Davidson battery, I just haven't figured out where to mount it yet. I'm also holding out because I may need a new starting battery. If mine goes out then I'll just get a chevy battery because of the dual batter connections to make wiring a ton easier.

Jackpine
Wed, June 15th, 2011, 12:06 PM
jmt0645 - Didn't you forget to mention the electric chair you have bolted in back there in the bed? I know with the setup you have you must drive around to the prisons "to give them a hand" with some of their "disposal" chores. :hehe:

With the wiring and alternator you have, there are NO power losses. Things are fine just the way they are. 12.6V no load is fine too, especially if you didn't disconnect the cables from the batteries. With three batteries wired in parallel, the voltage you see will be that of the weakest one.

- Jack

jmt0645
Wed, June 15th, 2011, 06:33 PM
jmt0645 - Didn't you forget to mention the electric chair you have bolted in back there in the bed? I know with the setup you have you must drive around to the prisons "to give them a hand" with some of their "disposal" chores. :hehe:


- Jack

:rofl: i can probably help help them alittle bit