I'm looking to replace my UBER-powerful 35 amp alternator in my '79 civic with an even MORE powerful 1-wire setup. I'd really like to eliminate the external regulator as a point of failure. I'm looking for anywhere from 80-100 amps and, honestly, the more compact, the better.
I remember someone saying something about the GM 12-si alternator in that "go-to parts" thread but I have no idea what they are off of.
Thanks, Parker
Full size GM trucks, IIRC.
You can find smaller versions in the GM FWD's.
I don't know of any self-exciting (one wire) alternators in GM vehicles from the factory. Most parts stores can get a Delco one-wire alternator.
Later 10si and all 12si GM alternators are self-exciting, its just that you have to rev them past about 1500 alternator RPMs for them to self-excite.
The other two wires are pretty easy to rig up; one is ign switched and the other is battery.
Basically, any internally-regulated GM 3-wire alternator can be used as a 1-wire alternator, but just know that they won't charge until you blip the throttle
The saab 9000 alternator I bought to do the 115amp upgrade on the mercedes is two wire, one for charging and the other for the charge light.
The problem with putting a larger capacity alternator is they are physically bigger and heavier than a smaller capacity alternator. It costs you power in the form of parasitic drag from the alternator. In planning my conversion to 115amp I found out that it would cost me 5hp or around there. I didn't think I wanted to give up that much power but the stock 55 amp alternator on my mercedes is underpowered for all the stock BS on my car. I'm going to do my homework before doing the conversion.
that's at full juice.. after recharging the battery from starting.. the drag should be less
All my alternators are 3-wire and excited externally. But thanks for asking. 
I have delco cs130 alternators converted to one wire setups in my Mini and my BMW. They came on about everything GM as far as I know. They can be clocked if the geometry doesn't match up with your mounts. I had to change the pulleys from a ribbed belt to a v-belt setup for both cars.
In both cases I had old tired alternators that only put out less than half of the replacement delco one. I got to ditch the external regulators - one of the best upgrades I did to the Mini. Much better now that I can run my high beam lights while idling and they are not dim. Low beams used to be noticeably dimmer at idle. On the BMW I went that route to support megasquirt and associated electrical loads (fuel pumps, wideband, electric fan, injectors).
one wire alternators are for race set up. No stock unit is one wire. The ZX2 has a nice 95 A. unit. the problem is always the mounting.
Most alternators can be run "1" wire.
but in reality even the "1" wire ones use more than a single wire.
Pick an alternator that fits your cars brackets and is internally regulated, the rest is easy wiring.
internetautomart wrote:Most alternators can be run "1" wire.
but in reality even the "1" wire ones use more than a single wire.
Pick an alternator that fits your cars brackets and is internally regulated, the rest is easy wiring.
Huh? How does a one wire use more than one wire?
On a VW (or pretty much any other older Bosch alternator), there are two wires from the factory, the tiny blue "exciter" wire that goes to the idiot light, and the big fat red one that goes to the battery. If you put a diode between the tiny post and the big post, all you have to run is the battery cable
All I know about electronics is the fact that electrons physically travel the opposite direction that every wiring schematic produced assumes they travel.
But more to the point, this guy does know a lot about them, and he hates one wire alternators. Rather than trying to understand why and convey it to you, read this: http://www.madelectrical.com/electricaltech/onewire-threewire.shtml
Also, I don't think GM ever put a one wire alternator in a car or truck.
I apparently should have worded my question more carefully :P
The OEM alternator is a measly 35 amps, and is about 6" in diameter; bigger than most I've run across. Mounting space shouldn't be an issue.
It looks like the Delco cs130 was used on nearly everything GM from 1996--2001 so that seems like as good a place as any to start. Is there any problem with running these CCW on a Honda motor, as far as cooling goes? I thought they had internal fans which should make it pretty hard to flip them around...
