Upgrading from 130 to 200 AMP 3 G alternator Upgrading

[rideapony]

Hi all I've been researching regarding the possibility of upgrading the 130 AMP alternator I have on my 1990 GT which came from from a SN95. According to my investigations this alternator is what they call "Large case" So my project is to change the output of this alt. to deliver 200 AMP. For this I'm going to replace the Staor and Rectifier with HD units for 200 AMP.

The main reason for this upgrade is because my Alt. started acting like one of the bearings was seizing and was friying my belt with loud squeling noise. I took it apart and cleaned the housing so I decided to paint it and it looks nice . So I told myself why not to upgrade it to a higger output just in case. I need more juice later.

By the way I just finished installing a new DCC fan controller. That is a nice piece and works smooth. Special thanks to Brian Baskins (Owner) for his advices.

Anyways this thread is to ask anyone that has done this alternator upgrades for any ideas or tell me if is not possible.

Thank you all, Nick

 

[vristang]

Seriously doubt you will ever *need* 200A...

I have a 165A alt, and it does just fine...


One downside I ran into was that the higher output alt doesn't seem to hold up to high rpm blasts as well...
For a while there, I was rebuilding the alt about every 10-12 months.
I finally put a slightly larger pulley on it (dropping the output, but decreasing the stress), and it has been good for a couple of years.

good luck,
jason

 

[HISSIN50]

FFI has an article on doing a 200 amp retrofit to a 130 amp alt IIRC.

I agree that you probably shouldn't need it. If the issue is low RPM charging, more absolute output probably won't help that anyhow.

 

[rideapony]

Thank you both for your ideas and observations. I agree withe the asumption that most likely there will be no demand for the 200 amp even with the fact that I'm using March U-drive pulleys and a taurus electric fan wired on the high speed. Initially that is the goal and the whole purpose of changing to 130 AMP to have enough current to feed the extra demand specially for he High AMPS demand required to start running the fan, but there are people assuring they where running the same fan with the stock 75 amp alternator

The fact of the matter is that just three weeks ago I was running my fan with a thermal switch and two relays and every time the fan was starting my idle would drop and started hunting for it until finally stabilize. Now it is different, my variable DCC fan controller starts the fan smoothly without sudden current spikes like before.

Well that is one part of my project, to be able to upgrade the alternator to 200 AMP the best way possible without having to rebuild it that often as happened to vristang. On the other hand HISSIN50 says that "If the issue is low RPM charging, more absolute output probably won't help that anyhow" Here is an aticle that might contradict this thinking. http://www.racesystems.com/3gproj/index.htm read the section "Stronger is better"

Please bring more ideas and or suggestions, by the way what is FFI?

Thank you all, Nick

 

[HISSIN50]

I think my point was missed (probably my fault for being vague). As I interpret it, the statement in the article pertained to a lighter duty cycle being favorable in terms of alternator lifespan. I totally agree.

My point was in comparing a 130 amp alt vs a 200 amp alt, when the 130 is probably sufficient as it is. Furthermore, if a 130 amp alternator has a low output at idle, a 200 amp alt won't necessarily have a greater output at idle. Note that it can be tough to find output specs for alts at low RPM's. Specs often start at 1K alternator RPM.

It was not meant to discourage you but rather a word of caution. Some of the SN95 guys go with 200 amp alts and have been a little disappointed that the idle output wasn't as great as hoped (seems to me that how the alt is wound and regulated comes into play there. A custom built unit by a local electrical supply shop [or done yourself] will be tailored for your desires).


A 6G is a nice alternative for your concerns as well, as it is kind of a heavy duty 3G, with better bearings and heat-rejection ability.

The one observation I can personally offer is the difference on my 94 GT with a stock 3G and a 160 amp aftermarket alt (~75 amps at idle, per the spec sheet). I noticed almost no difference between the two at 627 RPM with stock pullies. Both need a little more RPM to keep things where I'd like them. As you noted, going to a Delta controller (I went from OEM switching with relays to an FK-35. I use a 3.8L Taurus fan) really helped. The biggest difference was upping my commanded idle however.

At the bottom of this FFI page you can see the 200 amp rectifier. I thought there was an article about the retrofit but it might not have been on that site that I found it.

This is a good discussion (a nice break from the usual alt threads. And you have Jason posting on it. Few folks are as savvy as him).

 

[vristang]

I recently installed a Taurus fan on my cousins Fox...

We used the low speed with good results, using just a cheapo parts store controller. (the install had to happen that day, as there was no fan when the car was purchased...)

Just a thought...

 

[Mr_Q]

Know that PA Performance makes drop in 2G alts for our cars, for some time now, that are massively upgraded over stock. They only out put a little more in amps, 85a and 95a 2G models but because of this they truly drop in. They fit physically and won't put stress on the existing electrical lines like the 130a+ ones can. (since a lot of folks don't replace the wires).

It's important to know that it's not just 10 or 20 more amps you are getting with these replacements. The real upgrade is the quality of the internals versus stock and the lower RPM charging they offer over stock. They also off more "true" power under less load and will last a lot longer because of it.

Those are the biggest benefits you will see in real life.

 

[rideapony]

Yes in did this thread is very interesting and will help me understanding a bunch of things. I think you both have great points and I understand what you HISSIN50 are saying. But going back when I started posting in these forums I ike to do things by myself and that is what I've done to my ride since the begining.

I built my own 306 engine from scratch, rebuilt my rear with 3:55's, rebuilt my T5, install new clutch, upgrade to 130 AMP alt. rear disc brake conv. electric fan conversion with all the sheetmetal work, upgraded all the suspension with Poly components including five lug conversion, etc. etc. etc.
As you can see I've been able to do all of that which fills me with real satisfaction but also received a lot of help and ideas thru these forums from people like you and I allways be greatful for that.
I receive complements every day for what I've achieved.

Looking at the FFI yes they have the rectifier but I heard that in order to do the upgrade correctly I have to install a heavy duty Stator in other words both the rectifier and stator must be match to run the same current to work correctly. I found the Qwick Start webpage where they have those components. http://www.alternatorparts.com/3G_products.htm I'm also goig to replace the bearings, and brushes. I can do the assembly I just need ideas from people that did this before and to find the best components for a long life alternator.

Thank you all, Nick