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Alternator Swap out
https://slantsix.org/forum/viewtopic.php?t=49272		 Page 2 of 4
Author:  heavydoody808 [ Thu Jul 12, 2012 2:33 am ]
Post subject: 
The Subwoofer and amp came with an install kit. Purchased from Sonic Electronix:

http://www.sonicelectronix.com/item_379 ... ckage.html

I'll try and post pics.

From the battery:
Power cable to the big fuse: 40AMP AGU fuse mounted near the battery. then ran it back to the trunk to the amp.

I have noticed that the ammeter at idle is low when playing music. it charges as I drive and doesn't seem to be a big deal as it fully charges after some driving.

is there a link to info on the nippondenso upgrade?
Author:  heavydoody808 [ Thu Jul 12, 2012 2:50 am ]
Post subject: 
Quote:
The charging circuit must be upgraded before you upgrade the alternator -- it's marginally adequate for even the standard alternator. PowerMaster's alternator is probably not the best upgrade, either.
Dan, does this mean I need to upgrade to a higher gauge wire and a higher output voltage regulator?
Author:  heavydoody808 [ Thu Jul 12, 2012 3:00 am ]
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and BTW whta is the Stock ampage for the alternator?

50 - 60?

THANKS!!
Author:  Pierre [ Thu Jul 12, 2012 10:43 am ]
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Stock is probably less then that, 35ish?. The regulator will be fine, its the output wire thats of concern. The easy out is to run a heavy wire directly from alternator to battery (depends on which alternator you end up with, 2-4-6awg...) There is many a thread about upgrading alternators and bypassing amp gauges and various options. Use the search function for things like "alternator upgrade" or just "alternator".

That's not a 600w amp, look closer - 600w peak, 300w RMS. 40a fuse... its a modest unit at best. With HEI and even that modest amp it will make your lights dance at idle though.
Author:  SlantSixDan [ Thu Jul 12, 2012 11:48 am ]
Post subject: 
Quote:
Dan, does this mean I need to upgrade to a higher gauge wire and a higher output voltage regulator?
There's nothing such as a "higher output voltage regulator". You need heavy-gauge wiring and to upgrade or bypass the ammeter or convert it to a voltmeter.

For now, an easy immediate change to make the electrical system basically safe under the high load you're putting it under is to run two 10ga wires directly from the alternator's output terminal to the battery + terminal. Each of these two 10ga wires must have two 50A fuses, one located within inches of the alternator output terminal and the other located within inches of the battery + terminal. Put the wires in sleeve/loom and route them where they're not likely to be snagged or cut. Across the top of the radiator support panel with anchored zip ties works well, or tucked under the lip at the top of the rad support. Once you've installed these wires, your ammeter will no longer read correctly but you won't be running high current back and forth via thin wires through the firewall and low-rated ammeter, which is where the melt/burn/fire danger comes from -- and you can install a higher-output alternator.

I used to recommend an ammeter beef-up or stealth voltmeter conversion of the stock ammeter by R/T Engineering, but they split off that activity to Dashworx, and both companies now behave as though they'd probably lose toilet paper on its way from the roll to the intended application. I can't find the ammeter stuff on either company's page any more. There are other companies that do the stealth voltmeter conversion, such as this outfit. I've also seen people successfully buy an inexpensive generic aftermarket (e.g. Sunpro) voltmeter, take it apart, mount the old ammeter face over it and install the "looks like an ammeter but it's really a voltmeter" in the stock location -- connected appropriately for a voltmeter, which is different than the hookup for an ammeter. See here, and there's also a thread about it over here on another site (that site tends to have a lot more "noise" than this one so it's more important to filter the good info from the bad...the linked thread is fine, but if you're browsing along over there and you see something that interests you, post here and ask about it to double-check).

Another option: keep the stock ammeter but install an external shunt. See here for example.

What voltage regulator to get depends on what alternator you wind up with.
Author:  SlantSixDan [ Thu Jul 12, 2012 11:56 am ]
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Quote:
Dan, do you have said output curves of the various factory offerings?
No...I doubt if those curves ever escaped the confines of Chrysler Corporation's engineering department.
Quote:
My comments were strictly for idle output
Wide range there, too, from "almost nothing" to "adequate for reasonable current loads". This is dependent not only on stator and rotor configuration but also on pulley size (how fast the alternator is being spun at idle). There's no doubt the Nippondenso units all do better at idle than the '60-'88 finned-case Chrysler units, but some of the finned-case Chrysler units keep up with reasonably normal current loads at idle just fine. Of course, this what we're talking about sounds like a giant stereo system that draws more than "reasonably normal" current, so we're having an academic discussion here.
Quote:
The housing determines what parts can go in
Yes, and there have been many, many different rotors and stators and pulleys for the '60-'88 Chrysler finned-case alternators. Factory ratings went all the way from 27A to 78A, and there were even multiple different internal configurations to achieve the same rating depending on the intended application. Vehicles with tall rear axle ratios, four headlamps, and air conditioning needed (and got) alternators tailored for good low-RPM output, with small pulleys. Vehicles with deep rear axle ratios got alternators tailored for high-RPM output, with large pulleys.
Quote:
how much heat it can absorb
Heat rejection is a theoretical limiting factor, not a practical one with the finned-case Chrysler alternators.
Author:  SlantSixDan [ Thu Jul 12, 2012 11:57 am ]
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It might be good to have some more specifics on the car in question. Year and model?
Author:  heavydoody808 [ Thu Jul 12, 2012 12:18 pm ]
Post subject: 
Thanks guys! I appreciate it. Let me do some more digging and figure out my plan. Appreciate the help!
Author:  vynn3 [ Thu Jul 12, 2012 12:48 pm ]
Post subject: 
Quote:
For now, an easy immediate change to make the electrical system basically safe under the high load you're putting it under is to run two 10ga wires directly from the alternator's output terminal to the battery + terminal. Each of these two 10ga wires must have two 50A fuses, one located within inches of the alternator output terminal and the other located within inches of the battery + terminal. Put the wires in sleeve/loom and route them where they're not likely to be snagged or cut. Across the top of the radiator support panel with anchored zip ties works well, or tucked under the lip at the top of the rad support. Once you've installed these wires, your ammeter will no longer read correctly but you won't be running high current back and forth via thin wires through the firewall and low-rated ammeter, which is where the melt/burn/fire danger comes from -- and you can install a higher-output alternator.
Hey Dan, I know you're on record with your disapproval of madelectrical.com, but I've never actually read why. The upgrade you describe above is WAY easier than his. But why do you feel that his (much more involved) method inferior or unnecessary, aside from the fact that he's a Chebbie guy? Just curious... Thanks!
Author:  heavydoody808 [ Thu Jul 12, 2012 12:50 pm ]
Post subject: 
1971 Dodge Dart Swinger

Rebuilt Stock 225 Slant 6
Rebuilt A-904 Transmission
Stock (untouched) 7.25 Rear (have a 7.25 Sure Grip unit going in soon)
Rebuilt 9" Drums all around with Stainless steel lines
Aluminum Radiator with Jegs Chrome cylinder catch can
Rebuilt Stock Single Barrel carb
Electronic Ignition
BFG Radial TA tires
New Intake and Exhaust with 2" pipes, 1 Flowmaster 40 split out the back with stock Chrome tips
MSD Blaster 2 Coil
8.5mm Spark plug Wires
Stainless Steel Transmission cooler and fuel lines
Performance Suspension polyurethane bushings all around
New Mopar stock Leafsprings
Addco Front and Rear sway bars
New Antenna!! hehe!

Image

Image

Images are from 2011 prior to new Red Top Optima battery, Alipine/Kicker system and body work I am doing.

I'll post more pics next week when I'm a little further along.
Author:  Pierre [ Thu Jul 12, 2012 12:57 pm ]
Post subject: 
I think the moral of the story we can both agree on Dan is it is probably not worth the trouble finding the very specific rotor/stator combo to lead to higher idle output with the stock style alternator since the later model nippondenso is a relatively easy retrofit.

50a fuse on each 10g wire? Dan loves his overkill :) Then again I can't really talk here since I've been spoiled by my gm cs144 units - higher output at idle then the originals do at high speed. Check these graphs out. The aftermarket support for these is great, 200+a units available.
Author:  Blackdog [ Fri Jul 13, 2012 9:23 am ]
Post subject:  Related Alt-VR question
I seem to be in the market for both an alternator and VR. The VR I am replacing is the VR128. I am planning to go to the denso 50/120.

It looks like I can use a new VR128 with the Denso by grounding one of the field terminals. Is there any reason that I have to go to the VR125 two field wire VR.

I have done the recommended VR grounding and run the VR via a relay.
Author:  heavydoody808 [ Mon Jul 16, 2012 5:10 pm ]
Post subject: 
So this is the Alt I was thinking about:

http://www.jegs.com/i/Powermaster/713/17519/10002/-1

with Dan's link/advice would this work?

The only reason I am considering upgrading is because the in dash Ammeter is reading below center - for a while. It takes a drive to get it to remain dead center.

car starts and runs fine, np. should i even upgrade?
Author:  SlantSixDan [ Mon Jul 16, 2012 6:38 pm ]
Post subject: 
Quote:
Hey Dan, I know you're on record with your disapproval of madelectrical.com, but I've never actually read why
His methods are half-baked and in some cases technically/factually wrong.
Quote:
The upgrade you describe above is WAY easier than his.
Yes -- and it actually addresses the whole safety/adequacy deficit in the stock charging circuit, rather than just addressing one part of it. Fact is, the charging circuit on an old Mopar is marginally adequate except on cars factory-equipped with the 60-amp or bigger alternator starting in '73; those got a much heavier-duty charging circuit. But most of our cars didn't get that. Bypassing the ammeter addresses only the ammeter. My method above does that, too, and also addresses the bulkhead disconnect and the too-thin wiring. My method also includes correct and adequate circuit protection for the new cables. That's a long run of (very) high-current cable we're running from the alternator to the battery, no matter what route we take with it. If we put a fuse only at the battery end, that's fine if a short circuit occurs somewhere downstream of the battery. If we put a fuse only at the alternator end, that's fine if a short circuit occurs somewhere downstream of the alternator. But if we want to protect against the prospect of big, destructive, costly fireworks no matter where a short circuit might occur in that line (say...like...in the middle of the line, halfway between the alternator and the battery) we put fuses at both ends. For some strange reason this doesn't occur to the "expert" at MAD electrical.

His method for installing headlamp relays is similarly halfassed; it takes the workload off the headlight and beam selector switches, but that is only one part of the problem. It leaves the inadequate (too thin) factory headlight wiring in place. Fail! My way fixes the whole problem.
Author:  SlantSixDan [ Mon Jul 16, 2012 6:41 pm ]
Post subject:  Re: Related Alt-VR question
Quote:
I seem to be in the market for both an alternator and VR. The VR I am replacing is the VR128. I am planning to go to the denso 50/120.
Make sure you get hold of a real one, not a Chinese "100% new!" knockoff.
Quote:
It looks like I can use a new VR128 with the Denso by grounding one of the field terminals.
Correct.
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