3G alternator ?

Well, the obvious would be more wires....other than that it would be the amps supplied by the alternator. I've been usuing a reman 3g for 4 years or so with no problems, just upgrade your wire for the extra amps.

The 1 wire alternators don't start producing a significant charge until the RPMs get above 1200-1500 RPM. That means that you can still have a low charging rate at idle speed.

Think nightime driving on a stop and go freeway with the defroster on. The single wire alternator doesn't charge as well in this situation as a regular 3G alternator

I'd hate to see a stock alt run u/d pulleys, stereo, e-fan, windsheld wipers, ect all at the same time.

I just bougt two 3g alts for for both my foxs. Both are 150amp, but one is the wire conv. and the other is the 1 wire 3g alt. I've heard all you got to do with the 1 wire is just give it a little rev at start-up and your fine to get it charging.
Ive had two friends that have to do the same thing with there 1 wire.

Matt

I'd add that some one-wires have a provision to hook up the I terminal (to excite the alternator). That is a REAL nice option (as Jrichker said, self-exciting alts leave me a little cold).

Were it me, I'd also just do a conventional 3G style alternator. You can wire it so it is basically a two wire alternator (the power cable and the excitement wire are all that run to the chassis).

Good luck.

haoleboy72 said:

what does self excite mean? I seen 1 of the 1-wire that says it is self exciting, is this a option that is good for a street car? My other concern is that alot of the standard 3G say there is bracket modification needed and the 1-wire guys that I emailed all said it is a direct bolt-in.

Click to expand...

Exciting current is the small current needed to get the alternator to put out a current.

When the alternator is spun, it will not start to put out electricity until the field is excited -- the alternator needs a little jump start to work. A self-exciting alternator ("one-wire") uses the little bit of residual magnetism in the armature windings to generate the current to "turn on" the alternator. The residual magnetism is very small, so the alternator must be revved up beyond a certain RPM before enough current is generated to make the alternator self sustaining.

An externally excited alternator gets enough exciting current from the battery to make it self-sustaining at a much lower RPM.

A one-wire alternator is OK if you remember that you may need to rev the motor to get the alternator to start charging the system. It's possible that with an overdrive alternator pully that the initial start-up RPM of the motor may be enough to spin the alternator fast enough to get it working.

haoleboy72 said:

Also, does anybody have any advise on 3G vs 6G? what is the difference? benefits of one over the other?

Click to expand...

The only differences in the two Ford alternators, is that the 6G got more heavy duty bearings, larger fan and a better vented frame.
The 6G diode pack has the same amp output per diode as the 3G. The 6G rotor and stator have the same contact area, as a 3G.

Where the 3G vs 6G confusion comes in, is that with the release of the
6th generation alternator, Ford updated the amp rating (see below).
Sellers know this, and take advantage of the higher rating and
stretch it even further, by selling standard small case 6G models as 130amp, making the buyer think they're getting the same output as a large case 3G, but in a smaller package. < Very misleading!
Also, as for it being lighter and having less rotating weight < It's only lighter w/ less rotating mass if you compare the small case 6G to the large case 3G. There's also small case 3Gs and
large case 6Gs.

Here's the approx amp output of said alts.
Small case 3G = Factory rated @ 95 amps, Actual = 120a peak.
Small case 6G = Factory rated @ 110 amps, Actual = 120a peak (usually
misleadingly sold as 130a)

Large case 3G = Factory rated @ 130 amps, Actual = 160-170a peak.
Large case 6G = Factory rated @ 145 amps, Actual = 160-170a peak.

The above numbers are for genuine motorcraft standard output models.


The large case 3G and 6G both use a DE frame (front housing) size OD:
148mm/5.82"

The small case 3G and 6G both use a DE frame size OD: 135mm/5.31"

The advantages of the 6G over the 3G are almost null for fox apps. The better cooling doesn't do much, because the heat failures of 3G alts were only in extreme applications, where the current draw demands were putting near max loads on the alternator and doing it continuously. The larger bearings aren't much of a benefit either, because the brushes will wear out and the slip ring groove way before even the standard bearings will usually fail.

Next time you get tempted by the small case 6G claims, remember you're getting the same alternator as the 95a small case 3G, with only better bearings and cooling.
You decide....