wickedwarlock

iTrader: (4)

Hey, I'm not saying anything about your knowlege. Nothing personal, the high output alternators work slightly different than a standard one. That's what I'm trying to point out. I tested my 275 amp alt from alterstart. I tested the current from the alternator to the battery and it's higher than normal. Maybe the voltage regulator functions slightly differnt than the ones from the past. But after I did that, I see why they said to change it before installing it. And yes, It's been awhile since I had electronics class, damn 2 years of high school and 2 at college. But that has been 15+ years ago. The basics haven't changed either way but the devices from 15 years ago are different now.

WhiteBird00

iTrader: (4)

Yes, that's true. The higher output alternators are often used with voltage regulators that have higher limits. It isn't unusual to see a high-output alternator consistently put out 14.5 volts where a stock alternator is usually around 13.8 volts. That will add to the current flow somewhat as it tries to charge the battery to the higher voltage. But the difference shouldn't be that significant because it will be somewhat offset by the fact that other devices will draw less current at higher voltage.

I wouldn't want to leave the stock cable there forever but a few days won't hurt as long as the car's electrical system is stock and in good condition. It's always better to be safe with electricity so putting on the upgraded cable is something that should be done as soon as reasonably possible.

I'm not saying that I was working with vacuum tubes (although we did use punch cards to load the computer)

wickedwarlock

iTrader: (4)

Yes, it's solid state voltage regulator, I did read that about higher voltage and lower current. It just didn't make sense on the meter, lol.

That alt is set at 14.9V, and I get around 14.7 at the battery.

doh, punch cards, yes, I do remember those too. Just slightly before my time, hehe.

DuronClocker

iTrader: (25)

Just installed the battery and cable. Ran the cable from the alternator to the junction box and kept the stock alternator-battery cable as well as the battery-junction box cable, so it should provide the most available current to everything.

Couldn't use my old belt either I was using a 76" belt with my SLP underdrive pulley, now I need to use a 77". Wish I wouldv'e known about that beforehand, but all is running. Even warmed up and idling at just under 1000RPMs, I'm still right between the middle line and red dashed lines. My car used to drop to the middle mark at warm idle.

wickedwarlock

iTrader: (4)

so your running a pulley too? That's another can of worms with an aftermarket alternator, hehe.

Dal1as

You're running in to the same issue I had. My new alternator starts charging at 650 rpms now though so does fine.

You either need to bump the idle up a bit (Remember your tach isn't exactly accurate.) get a different alternator, or go to a stock pulley.

The alternator I got seems to work fine now but due to some other issues I'm not going to reccomend the guy yet.

DuronClocker

iTrader: (25)

If anything I want my idle a little bit lower. I should be okay with this alternator I think and the underdrive pulley. My commanded idle is supposed to be 950rpms. I'd like to drop it to 850-900 if I can. Car needs a bit more tuning down low. That won't happen for a little while still and I'll definitely make sure its all working right before I leave it that way.

Richiec77

iTrader: (3)

It's current Potential. It really doesn't mean you are going to have the full 200 A flowing thru the system constantly. It does mean that your voltage won't drop in order to supply the current needed up to around 200A. That increases potnetial output because Voltage x Current = Watts. Watts is a measument of work. Hence more work potential.

I would upgrade the alternator AND the main GND cables. Since a Vehicle is really suppose to be a closed Loop system contained to itself, it needs the ability to flow the current back to the battery. That is why you MUST upgrade the GND along with the power side. It's a closed system that doesn't work well with a bottle neck in there. It's also another way to introduce a Ground loop since current flows from negative to positive and has to make it's way back somewhere.

The vehicle has a current potential to handle 135A(Sort of). You just need to upgrade the main (BIG 3) cables to handle this new Current flow.

To recap the BIG 3 upgrade: Alt to Battery (+ wire). Engine to Battery(- wire) Battery to Chassis (- wire).

The smaller the wire, the more resistance it can create and become both a bottle neck and a fire hazard. 2/0 Welders cable is inexpensive, flexible and well designed to resist the elements and heat. Perfect for a car enviroment and the potential you now have.

You are going to experience a small drop in power because the stator is going to need more energy to turn it since the magnetic field is stronger. It maybe a max of 3-5 HP or ft lbs of torque. Not a whole lot really. And you are probably going to loose more speed in fact due to the extra weight of the stereo equipment then the power needed to drive the alternator. I would stick with the recomended pulley for your idle speed. The alternator manufacture SHOULD know this information.

gi8e7oi825

iTrader: (32)

I hate to bring this back from the dead, but I'm about to buy this alternator from GM Parts Direct... #15200109. Supposedly it's a 135 amp alternator. I've been having issues with low voltage at idle in park and drive since my recent pulley swap (Powerbond). I've seen other threads where the alternator pulley isn't the hottest idea, but a higher output alternator is. I'll never have an upgraded sound system, and all I have is nitrous with a controller, wideband, bottle heater, two fuel pumps, and gauges. The solenoids won't even be drawing current until WOT anyway. I want HIDs sometime in the future, too. If I get this alternator, will I too have to swap out cables? And, would this alternator be enough at idle? Think: staging lanes.

Thanks!

SmokingWS6

iTrader: (1)

I'm not sure what all the fuss is about. If your upgrading alternators you must have a reason for it, so you'll also need to upgrade the alt wire to the battery. its as simple as that. think of it this way, you don't build a 408 turbo motor and keep the stock fuel pump, so why keep the stock alt wire.

gi8e7oi825

iTrader: (32)

First, your analogy is extreme and doesn't apply in my case. If my stock electrical system is a stock 346, I want a mild H/C package. Not something extreme, especially not a turbo 408. I didn't replace my fuel pump for my H/C package... I did replace it, but for all that dry nitrous. Say I didn't get the nitrous... then I would never have needed the fuel pump. Sure other people's H/C setup needed a new fuel pump, but not mine. My question about the power cable is the same. Do I NEED to upgrade? If your answer is something like, "well just do it anyway" then could you also tell me what the actual gauge of the power cable from the alternator is so I can determine, for myself, whether or not I need to replace them? I'm not Nike, I don't just do it.

Second, will the 135 amp alternator even solve my problem?

SmokingWS6

iTrader: (1)

PlatnumStatuz

iTrader: (6)

JasonWW

iTrader: (2)

Some hi-output alternators have reduced output at idle in exchange for more output at higher RPMs. Always make sure you know what the current output is at idle.

Also, I would never run a larger pulley on the alternator. It may free up some HP, but it's never really worth it. The larger pulley slows down the alternator making it think it's at a much lower idle speed, say 500 RPM. It's just not going to put out much current at all.

It's also a good idea to upgrade the BIG 3 even with the stock alternator. The bigger the wire the better. I plan to run all 1/0 guage just to make sure I don't get any unneeded voltage drops. It can't hurt anything, only help.

gi8e7oi825, I would recommend using your old pulley. Even a high output alternator making 100A at idle will not actually do that as you have the underdrive pulley installed. Just do the pulley swap and see it that fixes your problem. Also, find out what that GM alternator puts out at idle, that's just as important (or more so) than it's max output.