mushaus

I recently installed a two 400 watt amplifiers in my trunk. My current alternator has 55 amps so I'm thinking it should be replaced.

Is there a way to determine how many amps are needed? Are there any concerns with running more amps through the original wiring?

I'm leaning towards a 100 AMP alternator something like this:
http://store.summitracing.com/partde...5&autoview=sku

I've seen the single wire Alternators that offer more amps but I really did not want to change the wiring.

fakesnakes

The simple formula is amps = watts/volts. 400/12 = 33 x 2 = 66 amps. However, I imagine the 400w rating is peak, not rms, so the true draw is significantly less. Personally, I would upgrade to a 100a alternator. The wiring is quite simple and a one-wire is the simplest, with no real wiring change needed.

You should not be running more amps through the original wiring as you should not be using any of the original wiring. Tap directly off the battery (solenoid connection) for the power leads to the amps with a minimum of 8 gauge new wire, fused with a 40 amp fuse to each amp. Use new speaker wire running from the amps to the speakers. Run an 18 gauge new wire daisy chained from the head unit to the amps as the power turn on. See, no old wire used!

mitzutuner

yes it is very wise to install a new alt. on your car. factory alts. are built to handle what the car is made for ex. headlights, tailights, gauge, factory radio, when you start adding aftermarket accesories to your car they draw more current, in turn cause the headlight dim you may have seen on some cars when they are playing their system.

yes the factory wiring, if it is too small of a wire, will need to be replaced, but only if it is too small, think of that as water in a hose, you wouldnt put a fire truck on a garden hose, it would burst, in terms kinda what a wire would do with too much current drawing through it, it would get hot and melt.

on some of our sound comp cars that have the big powermaster alts. on them we use a potentiometer to set where we need it then set it back down..... here is the link to powermaster, now they are only for spl competition vechilces mainly but it has a better right up on the way the potentiometer works, now im not saying you will need one of these because i highly doubt that you will im just saying that alot of the high output alts. on cars use these so they dont fry the wiring in the car. if i make any sense at all lol

heres the powermaster link http://www.powermastermotorsports.co...ternators.html

mitzutuner

or like the first guy said it in very simple terms, i guess i make things complicated trying to get them from my head onto here. lol sorry bout that

mushaus

fakesnakes, yes, I ran a 4ga wire to supply the Amplifiers and hooked it up as you mentioned. I was wondering about running a bigger Alternator using the original Alternator wiring and Voltage Regulator. Is this a problem or is it safer to swich over to a single wire internally regulated setup?

Adrenolin

As fake stated that the 400 is likely peak so it should be ok however upgrading to a new 100A Alternator would be the safe thing to do.

Note you should also install a Capacitor between the battery and Amp. These store power and delivers it to your amp when it peaks. This takes the drain off your battery and eliminates power draw issues like dimming headlights when the bass is thumping.

Norm Peterson

It wouldn't hurt to upgrade the alternator +wire. Occasionally, this wire may be asked to carry up to the full 100A, and its original sizing was for 55A or possibly less.

I'm just going to ask the question straight out - are those amplifiers 400W continuous (rms) or 400W peak?


Norm

kalli

a lot of good info here. the capacitor will also remove noise (you probably heard in another car the whee-whee noise when you flick on the wipers)

as to your question: 1 wire is not a poroblem. only easier

Kalli

mushaus

Norm, I installed a sub amp rated at 200w RMS and a 4 channel amp with 300w RMS.

Good idea about the capacitor. I've looked into these a little but didn't know they would remove noise as well as store up power.

TexasAxMan

Check out M.A.D. Enterprises web site. The guy has some real good arguements why a 1 wire alternator is not the best choice. The guy apparently doesn't communicate via e-mail, but I've been told he's willing to talk to almost anyone that has an interest in what he has to say.