Higher amperage alternator?
A higher amp alternator will run more accessories, plus give you a stronger current to run the whole electrical system. I bought one from afterthoughts and the only problem I have is that when my car idles, the electrical system runs on mostly the battery, so i have to sometimes give it a little gas to jump the volts back up. Other than that it runs fine when i'm cruising down the road. If anyone has a better explanation of why I am losing volts at idle please let me know. THANKS
Yup he nailed it, I wouldn't even look at a higher amp alternator unless you had a lot of stereo equipment or something that needed the extra power. In fact, the stock alt is more than enough, people are swapping the pulleys and are relatively fine afterwards.
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Originally Posted by 99blue-Z
A higher amp alternator will run more accessories, plus give you a stronger current to run the whole electrical system. I bought one from afterthoughts and the only problem I have is that when my car idles, the electrical system runs on mostly the battery, so i have to sometimes give it a little gas to jump the volts back up. Other than that it runs fine when i'm cruising down the road. If anyone has a better explanation of why I am losing volts at idle please let me know. THANKS
a problem at idle, I'd swap it back to whoever I bought it
from for a different one. I'm not an electrical guru, but I
don't see why it would do that just b/c it's a higher output
alt. I'm with you, if someone can 'splain, please do.
When you buy a high amp alternator an important spec would be the 'turn on voltage' this essentially is rpm related and tells the alternator field to turn on and begin charging.
Just because the alt. is hi amp doesn't mean that you get the hi amps at idle - all depends on what rpm the turn on voltage kicks in.
So yes, at idle when the rpm's are low, if the alt excitation level is higher than this rpm - the alt will NOT be charging until proper rpm level is reached. This would be the reason you see increased charging after revving engine.
Unfortunately, once the rpm's drop below the excitation voltage, the entire ugly cycle begins over
Moral: When buying hi amp alt - be concerned with excitation (turn-on) and choose one with a lower rpm value in addition to total amperage available. The excitation level is actually more important as idle speeds are where you need the increased charging - not highway speeds...
-Jay-
Just because the alt. is hi amp doesn't mean that you get the hi amps at idle - all depends on what rpm the turn on voltage kicks in.
So yes, at idle when the rpm's are low, if the alt excitation level is higher than this rpm - the alt will NOT be charging until proper rpm level is reached. This would be the reason you see increased charging after revving engine.
Unfortunately, once the rpm's drop below the excitation voltage, the entire ugly cycle begins over
Moral: When buying hi amp alt - be concerned with excitation (turn-on) and choose one with a lower rpm value in addition to total amperage available. The excitation level is actually more important as idle speeds are where you need the increased charging - not highway speeds...
-Jay-
