98LimitedCustomized

Okay I am new to this board, but I've got an experience I'd like to share. I've got a very large stereo and accessories set up in my 98, and needed to upgrade the electrical system. I have 1 Optima Red top for starting, and a Yellowtop for the accessories. I've got a Hellroaring Technologies battery isolator to keep the batteries seperate and charged. Now, for the alternator, I went with a 200 amp model. How much did I pay? $750? $600? $400? Hell no! I have a 200 amp GM alternator in my TOYOTA and it only set me back $200. It was really a snap to put it. I had the guy at the auto electric shop put the correct Toyota wiring harness on it, and other than that it only took about 50 cents worth of washers to make it work. If you've got any question on this, or a stereo question, let me know!

THE04Runner

Good job, how did you get that deal? So any more specs on your truck?

waskillywabbit

iTrader: (-1)

Worthless without pics and details!

AUJWE

Post some pics and more information if you get a chance. There might be some folks on here with aux. lights who might be interested in that mod.

COYOTA $x$

heres an example

http://cgi.ebay.com/ebaymotors/ws/eB...category=33573

US $159.00

buy it now $179

dbikeman

Thats what excessive amperage alternators are...... Mine is a 215amp model and its basically a GM alt with a toyota harness on it.

Bumpin' Yota

For those of you who want to keep your OEM case, www.hoalternators.com they have a current 200 amp direct bolt on that's a TOYOTA case.

Mine is strong as hell and has minimal trouble keeping up with 8800 rms watts of power. My subs have a very hard time handling that power for long though....lol

There's a few of us who are into systems too.

dbikeman

How does your amp not suffer? Dont get me wrong, it just seems like 190amps wouldnt be enough to power those 4 puppies you got running.

COYOTA $x$

FROM THE Alternator sellers (who might pump up the figures):

FORMULA TO DETERMINE AMPS NEEDED
Total Watts divided by 15 = Amps needed.
You need 15 amps of alternator power for every 100 watts of stereo power PLUS the power needs of your car

lets see then, 88 * 15 = 6 more alternators ?



David,

Did your EA alternator drop in pretty strait forward, what mods did you have to do to drop that GM style alternator into your Runner ? (besides the toyota harness)

TIA

Duffdog

uh.... the easiest way to determine the actual max draw from any stereo, accesory combination is to add up the fuse ratings on the amplifiers-- for instance, if you have a 100A fuse for your amps, there is no way that your amplifiers could draw more than 100A for any period of time or the fuse would blow. so, just add all the power requirements for the car and the stereo and there ya go!

all done

T

Bumpin' Yota

Well I also have it charging 2 deep cycle group 34's as well. They also help to stabilize the voltage floor. Add that to the fact that these 4 L7 12s can't handle the power for longer than about 15 seconds and my alt has very little trouble keeping up. I mean at 2200 rpm the voltage might drop to 12.1 or 12.2 on the lowest bass hits at or just above Fb. But the moment it stops the voltage shoots right back up to 13.8-14.2 or so. The stock alt would take alll day to recharge the 2 group 34s.

I also never really listen to bass songs because the subs cant handle the power very well, and the looser the subs get, the quieter they get for some wierd reason. So I rarely street bang at volume.

MTL_4runner

The ratio is a simple electrical formula: Power = Amps X Volts

You just need to know what any 2 values in the formula are and you can calculate the third one easily.

Does the stereo equipment run on 15V or standard 12V?

If so then 15V is an overstatement for the charging system anyway, just measure it with a voltmeter at the battery with the truck running and you will get the true consumption for the equipment....should be like 14.3-14.7V or so.

934rnr

My high amp CS130 105 amp alternator only cost me $25 from the junkyard it failed a few months later though. I had to pay $107 for the second one. I had it tested it puts out actually 107 amps with full load.

Bumpin' Yota

P=IV
P/V=I

So figure 8800 watts divided by 12.2 volts. This would yield 721 amps on the output side of the amps not taking into accout their efficiency. Even my zapcos are only (guessing) 70% efficient, so tack another 30% onto that making it 928 amps. Most amps are usually only about 50-60% efficient so that formula could be considered correct...


However a few things that few people know about. When you play a transducer, the coils generate a magnetic field that interacts with the magnet's stationary field causing movement. HOWEVER that very movement of the coil in the gap generates it's own voltage and current (usually very small values) that actuall fight the amp. This power generated by the coil's movement is termed back EMF and is one of the several reasons your reactive impeadance spikes at any given frequency. Also the size of the box, and the ammount of excursion the sub is undergoing changes the reactive impeadance as well.

For instance, each of my 4 amps will generate 2200w x 1 each into a 2 ohm DCR load. However when I burp at 59hzat full volume, my reactive impeadance is 5.4ohms. Power generation into such a high load was also about 1600 watts per amp. (96.4vac and 16.4amps) A larger box will help to lower the impeadance a bit by virtue of letting the sub excurt more. And hopefully lower my note to the mid 40s where I need to be and the truck's transfer function will help me out a bit more.

COYOTA $x$

Whered you get 15 volts from ???
------------------------------------

Watts = volts x amps




using the aternator vendors suggestion of ratio... (and that alone)

8800 watts.... = 88 * 100 right ?

15 amps for every 100....

so 15 * 88 = 1320

200 amp alternator (has 1 right now) leaving 1120 watts and vehicle consumption

1160 (adding 40 for vehicle) \ 200 = 5.8

cant have a fraction of an alternator so that = 6 additional 200amp alternators to handle a "continous output". Fortunately burping isnt continous.


As BY explained, the system has to dip down to ~12 volts right after the burping starts because at that point its running off the batteries rather than the alternator.

dbikeman

Robb, the alternator was supposed to be a direct replacement, its not. It comes with a spacer to make it fit on the top bolt to mount it to the engine. The bottom bolt to adjust belt tension is way off. Me and a buddy had to weld up a custom bracket to make it work in my car. I would not buy one again if given the chance to. I would get a real direct replacement like Bumpin' is talking about. Stout shady had this alternator too and I dont think he is very pleased with his either. I cant speak for him though. If you are interested in one, consider mine and his opinions. you may want to pm him cause im not positive on his feelings about his, but I know im not satisfied with mine. Power is great, but its too much of a PITA.

COYOTA $x$

Thanks David !

Thats the kind of detail I was looking to hear.

dbikeman

No problem at all. I wouldnt want to see anyone else have to go through the frustration I did over an alternator.