Will a 130A alternator run all this?

[hari-bhari 10+ year member]

My stock alternator is not doing so well with my system, getting pretty nasty voltage drops with bass hits. Here is my setup:

1) MB Quart DSC4125 amp (600w RMS) for speakers

2) BA GT-24 2-channel (700w RMS) pushing an D4 IDQ running at 2ohms.

3) Optima red top battery

4) 4awg wiring from battery to amps

5) big 3 upgrade with 4awg wire

I get some pretty significant headlight dimming when the bass hits, and my resting voltage on the alternator is only around 13.8, so I think it's time to replace it. Also, my resting battery voltage drops to around 12.0 when the car is off (hopefully they will give me a free replacement for a new one).

Questions:

1) So will a 130A alternator plus upgrading to a Optima Yellow top solve my problems, or is 130A not enough? This will be the easiest solution, since the alternator is a direct bolt-in from a Toyota Highlander.

2) Do I need to rip everything out and run 0awg to the trunk?

3) Will a second smaller battery in the trunk (thinking a DEKA) help? Because I'm concerned that a 130A alternator won't be able to sufficiently charge two batteries.

I guess the alternative is to just get a beefy 200A alternator, but I can't find one for less than $350, whereas the above proposed solutions will only cost me around

Please let me know your thoughts, thanks.

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[Supercharged DD 10+ year member]

You should be fine with a new yellowtop and a 130 amp alt. Many people are able to run up to 1200 with stock everything. If you get a yellowtop, thatll be even better than, say, a duralast batt. So you should be fine mate. What ohm load are your amps wired to? Could be drawing more current if wired too low. Also, how are the gains set? If you have them maxed out, itll pull alot more current.

 

[IonRL205 10+ year member]

130 amp alternator, optima yellowtop and big 3 and you should be fine. I run 1500watts on a 140 amp alternator and a yellowtop with 2 gauage wiring and I don't have any problems.

 

[Buck 5,000+ posts]

You should be fine. What vehicle is it?

 

[hari-bhari 10+ year member]

it's a 2000 toyota solara, i did the big 3, but with 4awg wire. i can swap it for 0awg in the engine bay if that'll help, but everything going to the amps is 4awg.

the 4 channel is wired to a 4ohm load, the sub amp is wired to a 2ohm load.

another question: does it make a difference if i keep the source bass volume at 5, and gain at 10, vs the source bass volume at 10 and gain at 5. (i know there is probably an SQ difference, but what about power draw?)

 

[trumpet 5,000+ posts]

If you're seeing 12.0 volts measured at the battery after running the engine you need to get that battery fully charged. Don't rely on the alternator to charge it as that's not what an alternator is for.

Get that charging system tested. You shouldn't be experiencing drastic light dimming with your setup.

 

[IonRL205 10+ year member]

it's a 2000 toyota solara, i did the big 3, but with 4awg wire. i can swap it for 0awg in the engine bay if that'll help, but everything going to the amps is 4awg.
the 4 channel is wired to a 4ohm load, the sub amp is wired to a 2ohm load.

another question: does it make a difference if i keep the source bass volume at 5, and gain at 10, vs the source bass volume at 10 and gain at 5. (i know there is probably an SQ difference, but what about power draw?)

Yes it can make a difference, the difference between whether you're sending a clipped signal or not. Just set any bass enhancements to flat and use a DMM to set your gain or give yourself a good starting point, then make any minor adjustments.

If you're seeing 12.0 volts measured at the battery after running the engine you need to get that battery fully charged. Don't rely on the alternator to charge it as that's not what an alternator is for.
Get that charging system tested. You shouldn't be experiencing drastic light dimming with your setup.

He said it sits at 12v with the engine off.

 

[Sleeklsc 5,000+ posts]

nm

 

[hari-bhari 10+ year member]

yea, right when i turn the car off, its around 12.3, but when i come back a few hours later its usually 11.7 or so. car starts up no problem though. also my voltage on the alternator when i first turn on the car is around 13.9, but after driving for about 10 minutes levels to around 13.4-13.5. i think this probably all points to an alternator problem, no?

also, will swapping my big-3 wiring to 0 gauge make any difference over the 4 gauge i have now? it's all in parallel to stock wiring so i thought it would be sufficient.

 

[TheUnderFighter 10+ year member]

the 1/0 wiring instead of the 4g will definitely be an improvement. I'm running just over 1200w on OEM battery and crappy stock alt, with only the big 3 done as an upgrade, and I only get dimming with bass tracks at higher volumes, or rap at high volume, and it's still not bad, just noticeable.

So your dimming should certainly not be that bad with that set-up. But you would also be very well off once you upgrade to that highlander alt, and do a proper big 3, you'll be fine.

 

[bgowdy 5,000+ posts]

sounds like it should be fine. I run a sundown saz-2000d. stock alt 14.4 volts and mine never drops below 14v even when i compete.

 

[hari-bhari 10+ year member]

sweet, thanks guys. im really hoping the new alternator will solve this, because im getting nasty dips into the 11s when the bass hits, and its preventing me from fully enjoying my system.

 

[BrownVanMan 10+ year member]

That resting voltage seems low. Do the big 3 in 0g and have the bat load tested/replaced.

On a side note there's better batts for the money too.

 

[ColterDC 10+ year member]

sweet, thanks guys. im really hoping the new alternator will solve this, because im getting nasty dips into the 11s when the bass hits, and its preventing me from fully enjoying my system.

I'd start with the battery, but just have the battery and alt tested before spending $$ on stuff you don't need.

Also are your grounds at the chassis, engine block and amp good?

 

[hari-bhari 10+ year member]

hey guys, so i went to two different places today and they said my alternator was good (i actually had already upgraded to the 130 amp toyota highlander alternator in 2008, but i thought it was going bad so i was planning on getting a new remanufactured one with liftetime warranty). resting voltage with the car on was 13.7, and under load (headlights, ac, etc), was 13.6. Also, my resting battery voltage was a tad low at 12.3, so i can get it recharged. I don't know if this points to an alternator issue, even though the tests showed that it was ok. Isn't it supposed to hover around the low 14s?

With that being said, I don't know why I'm getting nasty drops to the 11s with loud bass. Ive checked all my connections and grounds, and they appear good.

I am also planning on upgrading to a yellow top, and running 0awg for the big 3, and to the trunk for the amps. Beyond that, i will probably need a new alternator and also a second battery in the trunk.

is there any way to measure the maximum current output of the alternator, to see if i am really achieving the 130a like it says?