HO Alternator
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Joined: Oct 2002
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From: Neshanic Station, NJ
HO Alternator I've noticed for a while my stock alternator just doesn't seem up to the job. I don't have anything too crazy (a smaller system, heated seats, line lock, underdrive pulley), but it just can't handle much load. If I put on the A/C, radio, and headlights, at idle (~750-900rpms) it seems to hang barely above the orange area on the gauge and even at 2000 rpms seems to be maxing out just under 13. I wanted to get a slightly beefed up alternator and had found the Powermaster 150amp at WS6 Store. Anyone know if it's any good? Also I read that it's recommended to beef up power cables when going with the heavy duty alternators (200+amp). Would I also need to upgrade the wiring with the 160amp?
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Launching!
Joined: Oct 2002
Posts: 217
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From: Neshanic Station, NJ
I got them a number of years ago, but I believe it was from Fast Toys. I did do the install myself and in the middle of winter (carried my seats in the house just so I didn't freeze doing it). It took a little time but wasn't that hard to do.
I went with a 200 amp alternator that uses the truck casing - I got it from Alterstart (Ebay). It has been great for me, but I don't daily drive the car.
That said, you need to be aware that an underdrive pulley might cause problems with an aftermarket alternator - the 160-amp alt. that I had for a while would not charge at idle (800 RPM) with my underdrive pulley. I had to bump the idle up to 900 RPM to keep from having that issue. The more I looked into it, the more I realized that this is pretty typical of a higher output alternator (at least the aftermarket ones) - they usually have a higher turn-on RPM, so if you are using an underdrive pulley, you might end up not turning it fast enough at idle.
Just something to keep in mind so you don't get blindsided by that issue...
That said, you need to be aware that an underdrive pulley might cause problems with an aftermarket alternator - the 160-amp alt. that I had for a while would not charge at idle (800 RPM) with my underdrive pulley. I had to bump the idle up to 900 RPM to keep from having that issue. The more I looked into it, the more I realized that this is pretty typical of a higher output alternator (at least the aftermarket ones) - they usually have a higher turn-on RPM, so if you are using an underdrive pulley, you might end up not turning it fast enough at idle.
Just something to keep in mind so you don't get blindsided by that issue...
Thread Starter
Launching!
Joined: Oct 2002
Posts: 217
Likes: 0
From: Neshanic Station, NJ
I went with a 200 amp alternator that uses the truck casing - I got it from Alterstart (Ebay). It has been great for me, but I don't daily drive the car.
That said, you need to be aware that an underdrive pulley might cause problems with an aftermarket alternator - the 160-amp alt. that I had for a while would not charge at idle (800 RPM) with my underdrive pulley. I had to bump the idle up to 900 RPM to keep from having that issue. The more I looked into it, the more I realized that this is pretty typical of a higher output alternator (at least the aftermarket ones) - they usually have a higher turn-on RPM, so if you are using an underdrive pulley, you might end up not turning it fast enough at idle.
Just something to keep in mind so you don't get blindsided by that issue...
That said, you need to be aware that an underdrive pulley might cause problems with an aftermarket alternator - the 160-amp alt. that I had for a while would not charge at idle (800 RPM) with my underdrive pulley. I had to bump the idle up to 900 RPM to keep from having that issue. The more I looked into it, the more I realized that this is pretty typical of a higher output alternator (at least the aftermarket ones) - they usually have a higher turn-on RPM, so if you are using an underdrive pulley, you might end up not turning it fast enough at idle.
Just something to keep in mind so you don't get blindsided by that issue...
I wonder if it would be better to get an 'overdrive' alternator pulley?
I'd have to go check my build sheet...that was the nice thing about Alterstart - they provided a print-out with my alternator that showed its measured output vs. rated, and showed how fast the alternator was spinning to achieve that. They also stated what the turn-on RPM was.
My 160-amp alt. didn't come with that kind of information, nor do I believe it was even tested before being tossed in a box and shipped to my door.
If you go with an aftermarket alt, go with one that comes with a test sheet. If you are buying it from a distributor, find out who is making the alternator for them and give them a call. See if they test them/measure their output to verify their work. If they don't, find a different company.
My 160-amp alt. didn't come with that kind of information, nor do I believe it was even tested before being tossed in a box and shipped to my door.
If you go with an aftermarket alt, go with one that comes with a test sheet. If you are buying it from a distributor, find out who is making the alternator for them and give them a call. See if they test them/measure their output to verify their work. If they don't, find a different company.
You could always try the truck alternators. They put out 145amps I beleive, and should have a factory turn on rpm. Do a google search for KG3 alternator, that's the option code for the gm trucks with the 145amp alternators in them.
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Launching!
Joined: Oct 2002
Posts: 217
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From: Neshanic Station, NJ
So I actually emailed the company and asked them about the turn on rpm. They replied that it would turn on just the same as any stock alternator, but any speed below 2000rpm (alternator) would cause a severe drop off. How do I figure out my alternator's speed at say 800rpm (engine)?
Is it just easier to get an overdrive pulley? Or do the overdrive pulleys only fit stock alternators?
Only reason I wasn't looking at the truck one was b/c of the lack of the rear mount. I was concerned that could become an issue (the car does get driven on the road).
With the 200amp alternator, don't I need to upgrade my wiring? Trying to avoid that if possible.
Is it just easier to get an overdrive pulley? Or do the overdrive pulleys only fit stock alternators?
Only reason I wasn't looking at the truck one was b/c of the lack of the rear mount. I was concerned that could become an issue (the car does get driven on the road).
With the 200amp alternator, don't I need to upgrade my wiring? Trying to avoid that if possible.
So I actually emailed the company and asked them about the turn on rpm. They replied that it would turn on just the same as any stock alternator, but any speed below 2000rpm (alternator) would cause a severe drop off. How do I figure out my alternator's speed at say 800rpm (engine)?
Is it just easier to get an overdrive pulley? Or do the overdrive pulleys only fit stock alternators?
Only reason I wasn't looking at the truck one was b/c of the lack of the rear mount. I was concerned that could become an issue (the car does get driven on the road).
With the 200amp alternator, don't I need to upgrade my wiring? Trying to avoid that if possible.
Is it just easier to get an overdrive pulley? Or do the overdrive pulleys only fit stock alternators?
Only reason I wasn't looking at the truck one was b/c of the lack of the rear mount. I was concerned that could become an issue (the car does get driven on the road).
With the 200amp alternator, don't I need to upgrade my wiring? Trying to avoid that if possible.
