alternator question

norachelhere · 11-03-2007, 01:14 PM

where do you go to get a "better" alternator?
I've got several cars that all have systems, some better than others and if you watch closely, at idle, the headlights dim when the subs hit, and/or the idle will drop ever so slightly. Hooked up a voltage meter and you can watch it drop every time the subs hit. The GST I've got has a stock alternator and it only puts out 75 amps. I don't think the 240 or rx7 are much better. I would have to assume that an alternator with a higher amperage would have the nuts to sustain the added load.
Or am I attacking this from the wrong angle?

thanks for the help.

**P057** · 11-03-2007, 01:35 PM

Quote:

Originally Posted by norachelhere

where do you go to get a "better" alternator?
I've got several cars that all have systems, some better than others and if you watch closely, at idle, the headlights dim when the subs hit, and/or the idle will drop ever so slightly. Hooked up a voltage meter and you can watch it drop every time the subs hit. The GST I've got has a stock alternator and it only puts out 75 amps. I don't think the 240 or rx7 are much better. I would have to assume that an alternator with a higher amperage would have the nuts to sustain the added load.
Or am I attacking this from the wrong angle?

thanks for the help.

I would hope that a massive amount of power drain would make your voltage drop...

This is completely normal, and to be expected when you put in high power amplifiers to support subwoofers and non-stock speakers. The first thing to do that is the most important, cheapest, and easiest to do is to upgrade your "Big Three". Once that's done, check how the car reacts. Not enough? Upgrade your alternator. You'll have to find out from other members where to get them since I don't have a clue, nor am I interested. After that, upgrade batt/add a second batt. Don't bother with caps.

Notladstyle · 11-03-2007, 01:43 PM

Your idle RPM drops because the alternator has to make that extra current from somewhere - its not a magic device, it converts kinetic energy to electrical.

Need more electrical energy? It will tale more kinetic.

For the light dimming, that could be either that the alternator isnt fast enough to respond to the power demands, or the power demands are so great the alternator cannot produce enough power at idle. Neither one is a big deal unless your car lights dim while at 2k rpm.

bnorth1990 · 11-03-2007, 01:53 PM

Quote:

Originally Posted by P057

The first thing to do that is the most important, cheapest, and easiest to do is to upgrade your "Big Three". Once that's done, check how the car reacts. Not enough? Upgrade your alternator.

id have to agree with that

norachelhere · 11-03-2007, 03:05 PM

i understand why it does what it does. Not fast enough, not magic, and added load. makes sense. But I wasn't sure if increasing the amps would be the "right" way to go. I know when you go to shows, you see these guys with a million alternators. I don't want a million alternators. I don't want two alternators. I would assume that I would get one alternator to kinda meet in the middle of the stock one and two... Makes sense, right?

as for the "big 3", what is it?
The only big 3 I know of is a junk yard on 118th ave...

**P057** · 11-03-2007, 04:54 PM

Quote:

Originally Posted by norachelhere

i understand why it does what it does. Not fast enough, not magic, and added load. makes sense. But I wasn't sure if increasing the amps would be the "right" way to go. I know when you go to shows, you see these guys with a million alternators. I don't want a million alternators. I don't want two alternators. I would assume that I would get one alternator to kinda meet in the middle of the stock one and two... Makes sense, right?

as for the "big 3", what is it?
The only big 3 I know of is a junk yard on 118th ave...

Upgrading your grounds.

Just by doing this, you might fix your problem entirely.

bnorth1990 · 11-03-2007, 05:05 PM

1- battery negative to chassis
2- alternator to battery positive
3- chassis to engine

this might help http://www.sounddomain.com/ubbthread.../312025/page/1

norachelhere · 11-03-2007, 06:06 PM

thanks. i overlooked the alternator to battery connection when we upgraded connections and what not.
I've already got a better battery ground. and a better engine ground on all three cars... I'll do the alternator to battery next and see what kind of difference it makes...

**P057** · 11-03-2007, 06:27 PM

Quote:

Originally Posted by norachelhere

thanks. i overlooked the alternator to battery connection when we upgraded connections and what not.
I've already got a better battery ground. and a better engine ground on all three cars... I'll do the alternator to battery next and see what kind of difference it makes...

make sure it's a thick wire (to alt, from alt to batt). Will make a big diff.

Notladstyle · 11-03-2007, 09:18 PM

that will definitely help your dimming, not so much the idle drop though.

norachelhere · 11-04-2007, 01:24 AM

i know the idle is caused by weak spark and injectors not getting enough power to cycle properly.
I'm thinking a high out put alternator would also help with the car's overall performance too.
Now all I have to do is find them....

**P057** · 11-04-2007, 02:02 AM

Quote:

Originally Posted by norachelhere

I'm thinking a high out put alternator would also help with the car's overall performance too.

Heh, no it won't.

H.O. Alts usually sacrifice a little power in the low end and boost it up in the high end. Along with the added strain of having to turn a part with even more resistance, the H.O. Alts don't usually last as long either.

Notladstyle · 11-04-2007, 02:44 AM

Quote:

Originally Posted by norachelhere

i know the idle is caused by weak spark and injectors not getting enough power to cycle properly.
I'm thinking a high out put alternator would also help with the car's overall performance too.
Now all I have to do is find them....

you might get a stronger spark and SLIGHTLY better response from the injectors getting a voltage boost but I doubt you would notice it. Probably better mpg rather than HP.

**P057** · 11-04-2007, 11:34 AM

Quote:

Originally Posted by NoTLaDStyle

you might get a stronger spark and SLIGHTLY better response from the injectors getting a voltage boost but I doubt you would notice it. Probably better mpg rather than HP.

I would assume a slightly larger load on the belt and therefore the engine?

norachelhere · 11-04-2007, 12:40 PM

i agree, it would make for a higher load in the lower RPM range, but once you got it moving, i'm wondering if it would provide more than it is is taking. Ya know. I know road race cars have crazy alternators, especially when you consider the lack of accessories. I'll have to talk to some of those guys and see if I can get a decent reason as to why.
What do you guys think about making the alternator pulley smaller?
It would make the alternator spin faster at idle, therefore making a little more power, but would it cause a problem in the higher rpms?

11-03-2007, 01:14 PM	#1 (permalink)
norachelhere fails..... Car: My TRGarage : 2147483647	alternator question where do you go to get a "better" alternator? I've got several cars that all have systems, some better than others and if you watch closely, at idle, the headlights dim when the subs hit, and/or the idle will drop ever so slightly. Hooked up a voltage meter and you can watch it drop every time the subs hit. The GST I've got has a stock alternator and it only puts out 75 amps. I don't think the 240 or rx7 are much better. I would have to assume that an alternator with a higher amperage would have the nuts to sustain the added load. Or am I attacking this from the wrong angle? thanks for the help.

11-03-2007, 05:05 PM	#7 (permalink)
bnorth1990 Registered User Car: My TRGarage : 10	1- battery negative to chassis 2- alternator to battery positive 3- chassis to engine this might help http://www.sounddomain.com/ubbthread.../312025/page/1 Last edited by bnorth1990 : 11-03-2007 at 05:08 PM.

11-03-2007, 01:43 PM	#3 (permalink)
Notladstyle King of Ricers Car: = My TRGarage Tampa : 199523425	Your idle RPM drops because the alternator has to make that extra current from somewhere - its not a magic device, it converts kinetic energy to electrical. Need more electrical energy? It will tale more kinetic. For the light dimming, that could be either that the alternator isnt fast enough to respond to the power demands, or the power demands are so great the alternator cannot produce enough power at idle. Neither one is a big deal unless your car lights dim while at 2k rpm.

11-03-2007, 03:05 PM	#5 (permalink)
norachelhere fails..... Car: My TRGarage : 2147483647	i understand why it does what it does. Not fast enough, not magic, and added load. makes sense. But I wasn't sure if increasing the amps would be the "right" way to go. I know when you go to shows, you see these guys with a million alternators. I don't want a million alternators. I don't want two alternators. I would assume that I would get one alternator to kinda meet in the middle of the stock one and two... Makes sense, right? as for the "big 3", what is it? The only big 3 I know of is a junk yard on 118th ave...

11-03-2007, 06:06 PM	#8 (permalink)
norachelhere fails..... Car: My TRGarage : 2147483647	thanks. i overlooked the alternator to battery connection when we upgraded connections and what not. I've already got a better battery ground. and a better engine ground on all three cars... I'll do the alternator to battery next and see what kind of difference it makes...

11-03-2007, 09:18 PM	#10 (permalink)
Notladstyle King of Ricers Car: = My TRGarage Tampa : 199523425	that will definitely help your dimming, not so much the idle drop though.

11-04-2007, 01:24 AM	#11 (permalink)
norachelhere fails..... Car: My TRGarage : 2147483647	i know the idle is caused by weak spark and injectors not getting enough power to cycle properly. I'm thinking a high out put alternator would also help with the car's overall performance too. Now all I have to do is find them....

11-04-2007, 12:40 PM	#15 (permalink)
norachelhere fails..... Car: My TRGarage : 2147483647	i agree, it would make for a higher load in the lower RPM range, but once you got it moving, i'm wondering if it would provide more than it is is taking. Ya know. I know road race cars have crazy alternators, especially when you consider the lack of accessories. I'll have to talk to some of those guys and see if I can get a decent reason as to why. What do you guys think about making the alternator pulley smaller? It would make the alternator spin faster at idle, therefore making a little more power, but would it cause a problem in the higher rpms?