Wiring second alternator

[fr33b1rth]

assuming that i got it all mounted, and it's the right alternator that will work on our motors, how would i wire a second alternator to completly seperate it from the stock charging system. i know i'll need a second battery, and i run the B+ to that, but what about the ground? the alternator grounds to the block right? should i isolate the alternator so it won't ground to the motor, and ground it to the second battery myself, or can i just ground it to the motor just like the stock alternator and ground the second battery to the body also? someone please help me out a little.

 

[Defiant]

Uh.... you'd probably have a lot less work just switching to a larger alternator, but if you're going to continue with this, check the RV sites for Battery Isolator setups.

Bizarre.

 

[defrag010]

setting up a big audio system?
dual alternators aren't really needed unless you're pulling like 200 amps constant.
I'd go with what defiant said and get a mean green high amp, and use an isolator with a few optima yellow tops in the back of the car.

But to answer your question, you ground it just like your original alternator, except you're going to need to upgrade wire gauge. Put 4 gauge from the Engine to the frame, the Battery - to the frame, and the alternator + to the battery.

 

[fr33b1rth]

Well i'm more looking for good, clean power. Gonna be pulling about 80a-100a mabie more, so the stocker just isn't gonna cut it. I would like to do this simply because something as simple as turning on your heater, or window defoger drops your voltage like crazy, which i use both a lot here in mighigan, haha. can anyone reccomend a good alternator for the load that i am pulling?

Going to be running:

2x JBL BP300.1
2x JBL P80.4

All going to be running:
4x JL Audio 10w0-4 playing 20hz-119hz
4x JL Audio 6w0-4 playing 120hz-230hz
2x Pair Swiss Audio SAC650 playing 231hz+

Neither of these amps are very easy on eating the power, and they like 11.5V+, so dual alternators are the best setup IMO. Just insures that they get the power they need all the time.

Should be fun

 

[Bostedquest]

Put it this way...
On my old car I had well over 800 watts or sterio going through it.
Then add in, fogs, def.... get the point?
It was not a DSM but a 140 amp alt did it great. Voltage never dropped below 14.5.
And with EVERYTHING on, it still had 65 left.

think it was from mr alternator or something cheesy like that.

 

[Bostedquest]

http://www.4alterstart.com/highoutputalternators/

 

[fr33b1rth]

Too bad i need one for the 1.8... unless the crank pullys are the same size? don't care about the bolts cause i'm custom making the bracket to eliminate the AC since it doesn't work anyways.

 

[Bostedquest]

Too bad i need one for the 1.8... unless the crank pullys are the same size? don't care about the bolts cause i'm custom making the bracket to eliminate the AC since it doesn't work anyways.

Did you read the description at all on the page?
it is for all 89-94 maybe 89-99.

 

[HighPsi92GST]

Did you read the description at all on the page?
it is for all 89-94 maybe 89-99.

did you? 1.8 eclipse and talon isn't listed there, i beleive that is what he is reffering to

 

[fr33b1rth]

http://www.4alterstart.com/pages/st...p://www.4alterstart.com/highoutputalternators

None of these cars listed use the same alternator as my 4g37. None of them even have a motor in the same family as a 4g37.

If the crank pully on the 4g63 and the 4g37 are the same size, then i can use the alternator no questions asked because i will be fabing the mounting hardware, but if it doesn't, then i'm screwed.

 

[defrag010]

bah, with two 300.1's and two 80.4's you're barely going to be pulling enough amps to max our your stocker. I had a 1200.1 running 1 ohm, and it only pulled around 85 amps peak burst. Two 300.1's are puny compared to a 1200.1.

I would just get your stocker rewound in the case that an aftermarket one won't fit. You can Easily rewind them to put out 80-100 amps at idle, and around 200 or so max. You will be just fine with your amps on a stock rewound alternator.

Off topic, but why are you running 4 midbasses and where are you going to stuff them? I Highly suggest ditching a pair of 6w0's and speakers and running One pair of Swiss drivers and One pair of 6w0 midbasses off of one 80.4. I assure you will have Much better imaging and overall tonal response. 4 midbasses would create a Nasty peak and would be pointless except to be loud. Oh, and it would also create a horrible soundstage. That way you can cut out one of the amps which you don't need.

 

[fr33b1rth]

well none of the speakers will be playing the same frequiences, and i'm looking for accurate midbass from 120hz-230hz which no "normal" speaker is capable of doing. The 6w0 is a real subwoofer. I have personally compaired these two speakers in a car, and the 6w0 is good upto about 250hz, and the 6.5" swiss audio midbass driver is good to about 225hz. I've got kickpanels in the works for the tweeter and the 4", 6.5 in the door, and 6w0 in the rest of the door. The 6w0 needs a very small sealed box to work well.

 

[defrag010]

Yeah, The only problem with midbass is that it's directional and will shift your sound way out of focus. You'll be fine without the 6w0's for midbass because about 98% of 6.5" drivers can respond down to 80 hz. I have Aura MR6 mids and 1" tweeters in modified Q-forms, and I get midbass all the way down to arond 60 hz or so. I used to have an OZ matrix 6.5" set in kicks in my truck and they would play stone flat to about 75 hs. After I sold the OZ's, I put a set of dynaudio mk3 3 ways in my doors and the 6.5" mid/woofer hit so low that I didn't even put a sub in there.

I say follow the KISS principle, because you're overcomplicating your system. A nice 6.5"/4"/1" 3 way system should give you frequency response all the way down to your sub crossover point. Make sure to deaden the doors that the 6.5's go in and you will be more than happy. Heck, the 5" mids I have in my beater car right now can play accurate down to around 100 hz, and they are in un deadened doors.

 

[purplerose]

Too bad i need one for the 1.8... unless the crank pullys are the same size? don't care about the bolts cause i'm custom making the bracket to eliminate the AC since it doesn't work anyways.

is this for a 420a 2.0l? the bracket? If so id like to know how your own bracket came out and if I could see because I need to make one as well thanks.

 

[lasershark]

is this for a 420a 2.0l? the bracket? If so id like to know how your own bracket came out and if I could see because I need to make one as well thanks.

Welcome to the forum, I see you are new...
Fyi this thread is over a decade old, and none of the members are still active. You can click on their avitar and see when the last time they logged on was. Good luck on your search.

 

[purplerose]

oh, did not know that but thanks