Page 1 of 2

Upgrading An Alternator

Posted: Thu Jul 21, 2005 10:49 am
by Minorthreat412
The other day I was driving around a Cavalier for 2 to 3 days. I threw my old system in there for an extra thump on the way to Cedar Point. I put the system in and I couldn't get it to sound right. It would have great bass when it wasn't turned up very high then when u wanted it loud (loud enough to hear on the expressway) the bass would fade away and sound like it was running out of power. I played with the output on the amp and screwed with my HU for a while. It seemed like it had too much bass at the beginning and too little bass when turned up.

I came to the conclusion that the tiny alternator in that cavalier wasn't putting out enough power. This is because the lights dim on the HU everytime the bass hits. Weirdly enough I had the same system in an identical cavalier about a year before.

My amp, subs, and head unit have been put in and taken out of several different cars. I change vehicles a lot. I've had a problem with noise coming from the subs for a while that I can't seem to solve. I noticed that changing vehicles made no difference. I'm pretty sure its my HU. Basically.....my stuff sucks I guess.

There are different alternators with different amp selections. Does anyone have an idea of what to look for if I were to upgrade the Alternator?

Thanx for reading and sorry for it being so long. I'll appreciate any help. =)

Posted: Thu Jul 21, 2005 11:29 am
by mikechec9
i was taught to divide the number of watts to the sub(s) by the voltage (12).
could be mistaken, but it has applied thus far.

Posted: Thu Jul 21, 2005 1:42 pm
by Justin from Detroit1
Well, divide it by 13 or 13.5 to give a more realistic rating. Alternator is only used when car is running, and a running car is generally 13v+

Posted: Thu Jul 21, 2005 1:56 pm
by GlassWolf
yes but that's not factoring in amplifier efficiency
then add your stock alternator's rating to that figure as well.

Posted: Fri Jul 22, 2005 4:15 am
by Minorthreat412
all of this gives me kind of information i dont know what to do with. Theres an alternator in jegs that I'm looking at. The cheapest one is 105 amps or something. Is that relatively close to what I'm looking for?

Posted: Fri Jul 22, 2005 5:52 am
by Justin from Detroit1
That is hardly more then stock. A higher one needs to be made. Check out http://www.motorcityreman.com they make HO alternators.

Posted: Fri Jul 22, 2005 6:10 am
by Minorthreat412
thanx a lot that helped tremendously =)

Posted: Fri Jul 22, 2005 10:09 am
by lotas
yeah like Justin said, 105 amps is nothing. That's probably at about 2000rpm, too. My stock Honda one was 90amps. My Excessive Amperage alt is around 100amp at idle, and 180 at 1800rpm. There might be an Excessive Amperage group buy going on right now at caraudio.com or one of those forums. I'd check it out. I got my 180amp alt for $260 shipped, with 6month warranty. I'd stay away from Iraggi, i've been reading a lot of horror stories.

Posted: Fri Jul 22, 2005 10:21 am
by sinister audio
i get my high out alternators from h-oalternators.com i think thats the website but i get them cheaper for being a dealer.

Posted: Fri Jul 22, 2005 11:20 am
by kevinberry1
sinister audio wrote:i get my high out alternators from h-oalternators.com i think thats the website but i get them cheaper for being a dealer.
I checked the website and it appears that you have to be a dealer to purchase directly from them.

The one Justin posted a link to looks like they only make them for domestic vehicles.