Ok, I'm running MS-1 on full standalone, thus no voltage regulator :( I'm currently running a 4g63 alternator (only 60 some amps). Works ok and keeps my volts around12.7-13.5. I m hoping swaping to the Saturn alternator (200 volts, which is closer to the stock 420a) will keep my voltage around 14.0/14.5. My questions is about the field wire. The gst alternator now has the volt field wire tied directly into the positive battery terminal, and I know that's probably not the correct spot. So where should the field wire be placed? With the factory setup using the ecu as the voltage regulator I'm not sure where I should tap the field wire to ensure everything is staying properly charged in regaurds to how the factory setup would. So any information that may help the situation would be amazing! Thanks in advance, hopefully I'll have it swapped over in the next week or two.

Originally posted by jdm1990
Ok, I'm running MS-1 on full standalone, thus no voltage regulator :( I'm currently running a 4g63 alternator (only 60 some amps). Works ok and keeps my volts around12.7-13.5. I m hoping swaping to the Saturn alternator (200 volts, which is closer to the stock 420a) will keep my voltage around 14.0/14.5. My questions is about the field wire. The gst alternator now has the volt field wire tied directly into the positive battery terminal, and I know that's probably not the correct spot. So where should the field wire be placed? With the factory setup using the ecu as the voltage regulator I'm not sure where I should tap the field wire to ensure everything is staying properly charged in regaurds to how the factory setup would. So any information that may help the situation would be amazing! Thanks in advance, hopefully I'll have it swapped over in the next week or two.

You have a lot of misinformation going on... Let me clear a few things up. First of all, the stock Saturn alternator that will fit our cars is not anywhere near 200 amps (not volts). They are usually 90-105 amps stock. The 4g63 stock alternator puts out 75 amps. A stock 420a alternator puts out 85 amps. Any of these can be rewound to create a "high output" alternator.

I had a 200A high output Saturn alternator for a while but it died, so now I'm running dual alternators. Any "1-wire" alternator would work nicely for you as it did for me as a secondary alternator. These alternators have a built-in voltage regulator that is powered by the alternator itself once it gets up to speed. This way, all you have to worry about is connecting the output (charging) wire to the battery.

Read my post here for more info: http://forums.2gnt.com/dcboard.php?az=show_topic&forum=5&topic_id=136932&mode=full

Thank you for catching my mistakes. I thought the 4g63 was around 160, Saturn 200, and ours was around 190. Guess I was off my 100 :P The built in voltage regulator is exactly why I'm currentoy running the 4g63 alternator. I kept having issues.with the external regulator so I did away with it, but the 4g63 alternator just isn't keeping the voltage where I would like it. Once.i start the car the volts are only around 10.5/11.2, once I keep the RPMs around 2,500/3,000 RPMs for about 10 seconds the volts will stay around 12.5/13.3. Sometimes a little higher but not often. But it is ok for the field wire to.be tapped.directly to the positive terminal? I know it sounds weird but I just wasn't 100% sure that was the correct location.

Ive had so many problems with the stock 420a alternators and just got a saturn 160amp 1-wire alternator and never had a problem with it. My volts stay at 14-14.3volts all the time. The stock 4g63 alternators arent that great they tend to be pretty weak is what Ive heard.
Also another 1-wire alternator that will bolt up to our motor is the GM alternator(with slight modifications of course).
The best thing about these is you only connect the battery + wire to it and thats all.

Hey Gruff, That Saturn 160 amp alternator... What car does it come from, so I know exactly what alternater will fit when I ask the guy at Autozone?

Originally posted by fast420a83
Hey Gruff, That Saturn 160 amp alternator... What car does it come from, so I know exactly what alternater will fit when I ask the guy at Autozone?

There aren't any stock 160A Saturn alternators that you can buy at Autozone. The Saturn alternators that fit our cars (with minor modifications) are from the '91-97 SC/SL Series 1.9L cars. They are 105A stock.

If you want a rewound high-output version of this alternator (or a stock one), you can get them here pretty cheap: http://www.motorcityreman.com/91scse1.html. You don't need the voltage regulator that they also sell unless you want to convert to 1-wire operation or if you are installing on a 4g63. Without it, it will use the voltage regulator built into our ECU.

Cool, Thanks, I knew nothing about this mod.

A main objective for the 1-wire mod is to eliminate excess problems with wiring throughout the ecu or external voltage regulator. So if you have problems later in the future with your setup, it will be easier to diagnose the problem.
And I dont think Autozone or those places even sell 1-wire alternators because I asked them once if they had them and they didnt even know what I was talking about.
But motorcityreman.com has pretty good alternators, I have two 1-wire alternators from them and they have lasted for years now and they also come with a lifetime warranty on all their alternators.

That's good to know. My alternator is bad, and I will definately be getting one of these alternators from them... It's a direct bolt on with no modifications, right?

Originally posted by fast420a83
That's good to know. My alternator is bad, and I will definately be getting one of these alternators from them... It's a direct bolt on with no modifications, right?

You'll need a Saturn pigtail and the only other mod required is shown here: http://forums.2gnt.com/dcboard.php?az=show_topic&forum=5&topic_id=136932&mode=full#136942

Couldn't I just bypass the extension, and bolt it directly to the bracket by just getting a longer belt?.. and what pigtail will I need?

Originally posted by fast420a83
Couldn't I just bypass the extension, and bolt it directly to the bracket by just getting a longer belt?.. and what pigtail will I need?

No. It's not the belt that's the problem. The alternator is "hinged" by a bolt on the bottom that mounts to another bracket.

The pigtail is needed because the plug used to plug it in is different that the one used on our cars. You can get it here: http://www.jayracing.com/index.php?main_page=product_info&products_id=208

Of course, if you convert it to a 1-wire setup, you won't need the pigtail because the external voltage regulator takes care of that.

I have an extra pigtail I got with my alternator that i dont need. Id op. for the 1-wire alternator so not have to deal with the extra wiring.

I was actually able to run the gst alternator without making an extension for the top bolt. The only draw back is that I don't have a top tensioner so I have to use a pry bar and a 12mm socket. but no extension plate :P