200 Amp high output alternator and cabling

p m

Administrator
Staff member
Apr 19, 2004
15,617
838
58
La Jolla, CA
www.3rj.org
Quick response from seller:
"the stator, rotor and diodes have been upgraded."

That makes sense. There are also pulleys of two different sizes - IIRC, P38A one is smaller in diameter, so you could squeeze more juice out of alternator at lower RPM (but your tachometer will no longer read correctly).

There are several good shops in San Diego - Premier Rover and Sport Utility Motorcar first come to mind.
 

mbrummal

Well-known member
Jan 23, 2009
2,893
22
Willow Spring, NC
That makes sense. There are also pulleys of two different sizes - IIRC, P38A one is smaller in diameter, so you could squeeze more juice out of alternator at lower RPM (but your tachometer will no longer read correctly).
D2s (and Bosch P38s) get the tach signal from the ECU so the pulley size shouldn't affect it.
 

kennith

Well-known member
Apr 22, 2004
10,891
172
North Carolina
Yep it is stock, then rebuilt with higher AMP hardware. When I had an 05 Rubicon I found out a Durango alternator was 160amp vs a 130amp in my Rubicon. Cheap & simple upgrade, and online or rebuilt locally it could go up well past 200AMP and MUCH cheaper vs a Mean Green Alternator.

I'm sure it's a hell of a lot easier to get than a Mean Green. I've actually been to their facility, and it's one of the strangest places I've ever encountered. That said, their stuff tests just like they say it will. If they're doing DII alternators now, they'll be the ones pattered after what they made me when I brought my DII there a number of years ago.

Tested to over 300 amps... And it's tiny.

They have the capability to make pretty much anything if you can keep them in one place long enough to ask. You're not buying rebuilt units from them: They're making them from scratch; including the housings. It's fucking nuts. They've got some extremely expensive machines in a small, cold room.

Alternators for people like us are a side-job for those guys when they're not working on something more important.

Cheers,

Kennith
 

kennith

Well-known member
Apr 22, 2004
10,891
172
North Carolina
They haven't seen your man-love bouncy castle.

I assure you that if I dressed up as Princess Elsa and jumped in a man-love bouncy castle doing my absolute best gay leprechaun impression while singing show tunes with Dan Chapman, it would still be peanuts compared to what they've got going on...

Cheers,

Kennith
 

K-rover

Well-known member
Jan 15, 2010
2,163
62
Raleigh, NC
Ive had my ebay 150 amp alt in the truck for a little while now.. I monitor voltage real time with an app. Even after the new alt, the voltage under normal driving conditions ranged from 13.4-14.1. I had yet to put a load on it until last week, when I got my ARB compressor installed. While airing up my tires I noticed the voltage stayed at 14.1 the entire time the compressor ran. Once off it went back to jumping between 13.4-14-1.

Im considering it good! With my old 130 amp, When I used the winch the truck would want to shut off and voltage would drop to 12.8ish..
 

robertf

Well-known member
Jan 22, 2006
4,780
355
-
ok boys, you got me thinking for a while.

To get the same alternator to produce 40% more current, you need slightly more than a new diode pack.
The stator winding should be able to support higher current; the existing one _may_ live through some short bursts of high output, but if you draw that much on a duty cycle higher than normal, you'll have a meltdown.

I think most modern voltage regulators use a switcher instead of a linear regulator, so that's got to be good for 10-20% efficiency increase and makes RPM a lesser weighted factor. Does anyone really need a 200 amp alternator if the 100 amp is capable of generating full power at near idle?
 

squirt

Well-known member
Nov 13, 2008
824
13
Los Angeles
....With my old 130 amp, When I used the winch the truck would want to shut off and voltage would drop to 12.8ish..

This is interesting. I have a factory original alternator on my D2, and I've never had any running issues or significant voltage drops with the winch running.
 

K-rover

Well-known member
Jan 15, 2010
2,163
62
Raleigh, NC
This is interesting. I have a factory original alternator on my D2, and I've never had any running issues or significant voltage drops with the winch running.

The old one was probably faulty even though AutoZone tested it and claimed it was good...
 

p m

Administrator
Staff member
Apr 19, 2004
15,617
838
58
La Jolla, CA
www.3rj.org
I think most modern voltage regulators use a switcher instead of a linear regulator, so that's got to be good for 10-20% efficiency increase and makes RPM a lesser weighted factor. Does anyone really need a 200 amp alternator if the 100 amp is capable of generating full power at near idle?
Come on, even an old-school external linear voltage regulator barely consumed a few watts (they didn't even have any sizable heat sinks).
I believe the stock alternator is capable of producing close to 100A near idle - but if you rewind the stator with thicker wire, the peak output will shift to higher RPM and low-RPM output will inevitably drop.

Whether it matters or not depends on how the vehicle is driven.
 

Tugela

Well-known member
May 21, 2007
4,754
562
Seattle
I assure you that if I dressed up as Princess Elsa and jumped in a man-love bouncy castle doing my absolute best gay leprechaun impression while singing show tunes with Dan Chapman,

I have $20 ready to pay for the live stream.