[torqhead]

Also, forgot to mention I got rid of the extra connection between the alt and battery. My current wiring supplies and 8 gauge wire from the back of the alternator to my distribution point.

["QUICK-SILVER"]

I'ld give the folks at Powermaster and Tuff Stuff a call and tell them what you're up against. The amp load you need may be too much for continuous duty on their 200 amp alts. Too much heat even for the CS144.
Surely they've tested them and can tell you go or no go.

And, an earlier post about heavy duty alternators got me thinking. Heavy duty charging was an option on some Pontiac models. I know it was in 76 when you could get a 27SI on a firebird. Requires different brackets and I think an idler pulley to run them. Don't know how big the 27SI is compared to a CS144. If it's bigger it might be a better option for a high amp upgrade.

So give them people a call and let us know what they have to say about it.

It would add a few more amps but the addition of an external cooling fan would make any of them last longer. Just a hose/duct from the cowl to the back of the alternator would feed cooler air into it while cruising.

Clay

[PontGuy]

A lot of your numbers look like mine- A/C blower, stop lights etc. But you have a lot more loads to consider. Sitting at a stoplight on a warm night with the A/C running and your high-power stereo going its going to take a bunch of amps. So its not just the total rating, you need an alternator that will put out the juice at idle. I understand the CS alternators do a whole lot better at idle than the older 12SI's so the CS144 is heading in the right direction. But I would still ask for low RPM output specs to make sure that you don't end up with a 200A alternator that won't put out enough at idle.

[HWYSTR455]

I dunno, something is going on here, there's just too much draw for some of the factory stuff, I'm thinking there is other issues. 18a for the fan just seems like a lot to me, I would go over the wiring for it, the switches, the relay, and the resistor. And certainly would go over the grounds, those need to be upgraded just like power cable do, and are often overlooked. And screw that crappy fuse and fuse holder right by the alt, worthless, and creates a resistance even.

You realize running the fans full time is a waste, right? There's no need for it, and it digs into your reserve = battery. If it's a dual fan setup, you run only one fan for certain conditions, and the second for high demand. Alt load takes power to spin, on the highway, you may even pic up some mpg if the fans are off. (just one example). A controller, or at least a temp switch, would help wonders. Could even do dual temp switches. one come on at like 185, the other like 195.

If you can fit a CS144, that's good, and one thing not mentioned is that CS series are 'electronic' friendly. Not that it makes that big of a deal, but it's nice to know. The CS130s are notorious for overheating, the IROC Z guys figured that out, and how a number of shops popped up doing 'custom' alts. I never had any luck with them. The bearings are smaller and are sensitive to belt tension, and the internals cook frequently in high load/demand conditions.

When you apply load to an alt, they generate heat, the more heat, the output starts sloping off. This is one reason your wiring needs to be in good condition, and properly configured. If you use too small of a wire, the alt tries to keep up, gets hot, and output starts sloping off, starting a cycle that degrades pretty quickly.

Output at idle, you can worry about that, but for the most part, it's a percentage of the total output the alt is rated at. Also, ones that are made to output more at idle trade off higher RPM output. So it's possible to cruise at an rpm where the output has already sloped off, and not provide enough.

Only place I've ever found that lists output of an alt, like rated, on a chart, is East Coast Auto Electric. They would provide a graph with every alt which shows the output at X shaft rpm. Not sure of their' quality now, when I tried them, they started having QA issues, and I had failures just like parts store crap.

Like I mentioned, search here, on my user ID and a keyword, like 'alt' or '12si', and you will see this all has been discussed a number of times. It took me years to get things sorted out, have had these issues since the 1990s. It wasn't until I rewired the OE harnesses that all my problems went away.

.

[george kujanski]

point of information: yes, as the alt gets hot, it's max output will reduce. In the pic of the Delco 12SI output I posted above, the curves show the output of the unit hot and stabilized, typically at a room ambient temperature, typically done by OEM manufacturers.

The pic of the OP's alt with the rating sticker probably shows the test current; the would be the instantaneous output, without the machine temperature stabilized. Typically done as a figure of merit for QC purposes.

George

[torqhead]

Originally Posted by HWYSTR455

I dunno, something is going on here, there's just too much draw for some of the factory stuff, I'm thinking there is other issues. 18a for the fan just seems like a lot to me, I would go over the wiring for it, the switches, the relay, and the resistor. And certainly would go over the grounds, those need to be upgraded just like power cable do, and are often overlooked. And screw that crappy fuse and fuse holder right by the alt, worthless, and creates a resistance even.

For the most part my primary engine bay wiring is all new including new fuse holder/fuse assembly, the only part I didn't replace was the wiring from the high speed blower fan relay to the fan. When I get a chance I'll try to do a direct connect wiring test to the fan, although it's hard to get to on a GTO since the fan is in the fender...

[torqhead]

During this week I've spent some time talking with a few folks about my power demands and everyone so far has indicated the different components and their power demands seemed reasonable. So I think my testing and results don't appear to be abnormal, but as I said previously it was a good exercise as I know for sure exactly what's required.

After talking to both PowerMaster and Tuff Stuff I decided to order the Tuff Stuff CS144 200 amp alternator, USA built in Cleveland and idle charging is rated at 100-110 amps. I've been running a factory CS144 140 Amp this week and running A/C full blast, stereo, etc. with no issues.

Thanks again to everyone that provided thoughts, ideas, input and previous experiences. That's what is great about this forum!

["QUICK-SILVER"]

Originally Posted by torqhead

I've been running a factory CS144 140 Amp this week

Hey torqhead,
What's the application for that alternator? And what all did you run into as far as fitment goes?

Need to know what to look for
Clay

[torqhead]

Originally Posted by "QUICK-SILVER"

Hey torqhead,
What's the application for that alternator? And what all did you run into as far as fitment goes?

Need to know what to look for
Clay

Hey Clay,
Hopefully I'm understanding your application question... I picked up an alternator #8226-P50A for a 1998 Cadillac Eldorado (based on George's input) and a connector #PT200 plug from Advance Auto Parts.

Only modification I had to make for mounting was the bolt is larger on the top mounting ear and had to drill out my mount bracket to accommodate. Attached two pics of the install, but it was pretty easy change.

[george kujanski]

Nice install.

george

[torqhead]

Originally Posted by george kujanski

Nice install.

george

Thanks George, although I need to get the rubber boot for the main power connection.

[HWYSTR455]

Ah, CVF pulleys/brackets, so that's how you got around the physical size difference.

What gauge charge wire did you end up with?

.

[torqhead]

Originally Posted by HWYSTR455

Ah, CVF pulleys/brackets, so that's how you got around the physical size difference.

What gauge charge wire did you end up with?

.

Even with my factory brackets I would have been able to install the CS144. Only reason I have the CVF is there was a mid-year change in 69 that made it challenging when I went to put on the A/C this past winter. A word of caution on the CVF brackets, what they deliver is incorrect and you have to modify them to make them work and line up correctly to avoid throwing belts.

I've got an 8 gauge wire, now that I know maximum amps I'm considering changing it to a 6 gauge this winter... jury is still out.

[torqhead]

I ordered and installed one of the Tuff Stuff 7290E alternators.

The first unit I received I noticed when I first start the car I've got 14.2 -14.5 volts and as the car and alternator warmed up (10-15 minutes later) the charging was down to 13.89 volts. This is with the car running at 1350 RPM. Next day after the car sat and cooled completely I went through the same process, 14.2 - 14.5 volts to start but after it heated up it was down to 13.89 volts. I could even hold the throttle to over 4000 RPM and it did not change, so I assumed I received a bad unit.

I received a replacement yesterday to find I basically have the same results, although the second unit after the alternator gets completely warmed up charges at 13.82 volts, 1350-4000 RPM and 71 Amps of power being used. Even if I shut A/C and all electrical off except for what's required to run the motor (about 36 Amps of power) the alternator only charges at 13.82 volts.

My understanding is a properly functioning alternator when charging should be a minimum of 14.2 volts and max at 14.5 volts. Contacted Tuff Stuff and they indicate range is 13.8-14.2 volts. Am I confused?

[Willshire]

Sounds like it is working a ok to me. If you can load it up and the voltage doesn't move, that's a good day

["QUICK-SILVER"]

Originally Posted by torqhead

14.2 - 14.5 volts to start but after it heated up it was down to 13.89 volts...............

I received a replacement yesterday to find I basically have the same results, although the second unit after the alternator gets completely warmed up charges at 13.82 volts, 1350-4000 RPM and 71 Amps of power being used. Even if I shut A/C and all electrical off except for what's required to run the motor (about 36 Amps of power) the alternator only charges at 13.82 volts.

My understanding is a properly functioning alternator when charging should be a minimum of 14.2 volts and max at 14.5 volts. Contacted Tuff Stuff and they indicate range is 13.8-14.2 volts. Am I confused?

I suspect their 13.8-14.2 volts Is 'real' output with a 'hot' alternator. Where most go by and test cold output....what you're getting when you first start it up.

You didn't say where you was checking voltage at. Curious about the difference, if there is any, from checking at alternator output (+) stud and what it is at the battery.
Clay

Originally Posted by Willshire

Sounds like it is working a ok to me. If you can load it up and the voltage doesn't move, that's a good day

I have to agree with that. And the fact that voltage doesn't change when going from 71 amps to about 36 amps...tells me that's one strong alternator.

[torqhead]

Originally Posted by "QUICK-SILVER"

You didn't say where you was checking voltage at. Curious about the difference, if there is any, from checking at alternator output (+) stud and what it is at the battery.
Clay

All of my testing has been done at the battery, although I did check at the back of the alternator out of curiosity and noticed a difference of .03 volts higher. This morning I went for a drive and when I got back I immediately checked the voltage at the battery (thinking it may make a difference with the car moving and keeping things a little cooler under the hood). Charging showed 13.99 at the battery, so I'm going to call it good!!!

Definitely a good exercise, learned a lot and now know exactly what's going on as it pertains to my charging system. This Tuff Stuff alternator is really nice, attached final product pic.

Dave

["QUICK-SILVER"]

Originally Posted by torqhead

. Charging showed 13.99 at the battery, so I'm going to call it good!!!

That's better than good. 13.99 at the battery means the alternator is doing more than that. So yes, 13.99 at battery while also supplying your amp load is definitely better than good.

Dang good looking engine by the way
Clay

[Bill Hanlon]

Originally Posted by torqhead

Even if I shut A/C and all electrical off except for what's required to run the motor (about 36 Amps of power) the alternator only charges at 13.82 volts.

I'm amazed it takes 36 amps to "run the motor".

[torqhead]

Originally Posted by "QUICK-SILVER"

That's better than good. 13.99 at the battery means the alternator is doing more than that. So yes, 13.99 at battery while also supplying your amp load is definitely better than good.

Dang good looking engine by the way
Clay

It runs really well too... 13.04 in the mile high city... Need to get it at the track again as I'm sure I can get it in the mid 12's now.