Stock alternator question

[ejschultz 10+ year member]

I ordered a Powermaster alternator that puts out 80 amps at idle and 140 amps at max load. I figure this alternator should be more than enough for my system under most circumstances, even at idle. I don't plan on upgrading my amps anytime soon and if I do, I'll be upgrading the alternator again and adding a second batter. To get to my question, my alternator now is 105 amps at max load. Does anyone know approximately what that would be doing at idle? It's a 16 year old AC Delco 105 amp small case (CS130) alternator.

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[Saint211 10+ year member]

Its tough to just guess but I had a car with a similar ac delco 105 amp alternator. My guess would be 60-80 amps at idle. Tough to say though because the ratio of power produced at idle and at peak isnt always linear. It depends on how the alternator is wound. For instance, if you have an alternator re-wound, it usually produced more power at peak and less at idle. What you have though should work fine as long as everything is wired correctly. I had a system of similar power in mine. One thing I would advise for your vehicle though is the big 3 upgrade. It helps A LOT on similar vehicles. When I had my corsica the big three upgrade raised my overall voltage by about 1.2 volts.

 

[ejschultz 10+ year member]

I'm hoping for a little bigger gain at idle than that. I'm going to get the stock alt tested before I swap them out just to see what kind of difference it'll make. Also, I've had the big 3 done for a while now with 1/0 and it helped me out by about the same as it helped you. I still get drops, but nothing like I used to. With my new mono amp though, I have dipped into the mid 11s which is why I got the new alternator.

 

[FenixAudio 10+ year member]

Its tough to just guess but I had a car with a similar ac delco 105 amp alternator. My guess would be 60-80 amps at idle. Tough to say though because the ratio of power produced at idle and at peak isnt always linear. It depends on how the alternator is wound. For instance, if you have an alternator re-wound, it usually produced more power at peak and less at idle. What you have though should work fine as long as everything is wired correctly. I had a system of similar power in mine. One thing I would advise for your vehicle though is the big 3 upgrade. It helps A LOT on similar vehicles. When I had my corsica the big three upgrade raised my overall voltage by about 1.2 volts.

****, a 1.2volt increase is alot. you must of had some old a$$ wire on there to start.

as far a idle current, you should be fine with 60 or higher unless you have more then 2 massive amps. your car doesnt use much current once started. the only way a 20ampre increase at idle is going to matter is if you sit ata light for 30 minutes with your highbeams on, wipers, horn blairing, radio all the way up and rolling your windows up and down over and over again while locking and unlocking your doors, and having the ac on at full tilt. then it will matter oh and you will need to be hitting the brakes at the same time. either then that you will be fine.

now if you are planning on havinga comp build or a highout put show peice then it will matter. but for ever day listeneing you will be fine. how longto you really idle anyway?

 

[ejschultz 10+ year member]

Lol, I actually idle for a while. My car is currently not insured so I start if up every once in a while and let it run. Of course, while it's running, I have to listen to music. I don't have any other accessories on though when I do it. It will (hopefully) be insured in the next two weeks. But basically, you're telling me that for my two amps, which aren't necessarily extremely powerful, 80 amps at idle should be more than enough? The amps I'm using are in my sig. Together, they're doing less than 1500 watts RMS.

 

[FenixAudio 10+ year member]

yes, you should be fine. no need for the up grades really. Id do the big 3 mabye if you were having some dimming issues but id go with what you have before you go and pay for all the other stuff. you can always upgrade later. i havea 97 sentra beater i drive to work everyday and i have a 4ch and a sub amp on my stock alt and batt and i did the big 3 and its fine. no idle issues or bogging down or anything.

Im about to up grade though. im switching out the set up. Im going to re do the cari think. you never see any sentras done up, so i might as well. Im going to add a 140 alt, 2 red tops, going to do 3 kicker cvx 10's, kicker 2500.1, kicker 6504, kicker 200.2, re doing the rear deck for 2 6x9" and 5.25" componets. re doing the front door panels for 2 sets of ks650 componets and possible doing the reat doors and adding a pair of ks650 comp there too. all running off the new avic-x920bt. should be pretty sick. Im also doing a body wrap with my company logo and a bunch of custom art from the grafics lady thats designing it. ill post pics of the project as i go.

 

[ejschultz 10+ year member]

You'll be happy with those CVXs. You sure the car has enough space to properly box them? CVXs like big boxes.

 

[FenixAudio 10+ year member]

ill make it work. i was thinking about building a dual band pass box with a ports through the rear seat into the car.