DMCfirestar500

Anybody know somewhere that I could get a decent H/O alternator for a reasonable price. I got a quote from h-o-alternators.com for $649 for a 170amp alt, that seems way to high. Anyone know anywhere else I could find one?

Matt93SE

iTrader: (44)

You don't need it. I've run with a 2500W RMs system in my car for the last 7+ years on the stock alternator. unless you're dumping more than about 5KW into the system all the time, you simply don't need it.

DaWifey's90

iTrader: (3)

whoa!! that's some serious cabbage!! have u tried ur local friendly generator repair shop. most places that repair/rebuild starters and alternators/generators will wind something special for ya for a few bucks more.

Loco7

iTrader: (1)

like he said you shouldn't need a H/O alternator as long as you have good grounds and proper gauge wire ran and a good battery and if need be multiple batteries. My buddy has a S10 and he had his alternator upgraded as much as possible and his lights still dim and his only running like 1500-2000 RMS (can't remember). so unless you have a ton of equipment running at all time you should need it but i doesn't hurt either don't get me wrong.

Like mentioned a local shop will upgrade you stock for about a third of that price maybe less! Remember if you do upgrade your alternator remember to upgrade your grounds and power line from your alternator to the battery

By the way why do you need a H/O alternator

vansskaterfreek

iTrader: (14)

if you wanan test one, i have a VG alternator..... or a VE alternator if that will work

DMCfirestar500

Well I was just getting worried. My setup right now is a single 12" IDMAX running 1500watts rms plus my component amp pushing 120watts rmsx2 so I guess I don't need one. My lights dim alot when the sub hits, and I already have a yellowtop, still have to do my big 3 so hopefully that will be enough.

Scope

iTrader: (5)

They are dimming because of the power surge. When the car is at cruise it probably don't do it. You will know when you need an upgrade when the car stutters or stalls under massive bass. I've ran about 1700 rms watts and ghetto rigged a grounding kit and that solve my problems and I had a cheapo battery.

95turbo gxe

iTrader: (25)

I call on this one. I had a wall with 5 solobaric 10's in it. I was running about 500 watts rms to each one and I had three batters all total and could not burp my system for more than 5 seconds. It would drop form 13.8 volts to 11.2-10.7 .Then my headunit what shut down do to lack of voltage. I went through about 2 alternator plus the one that was ont the car when I got it.

Loco7

iTrader: (1)

have you ever tried running multiple batteries. also how good is your ground?

I don't doubt your lights dim (ALOT) but if you upgrade all the electrical you shouldn't need to keep your foot on the gas to keep your power from dropping that much. at least that is my experience with massive stereo system setups

95turbo gxe

iTrader: (25)

ground good try differant ways also. Read my post as it says that I had three batteries.

DuniCraig

i am going to be putting 2000 watt amp running 2 1200 watts subs and then the speakers which are running off a 200 watt headunit. Now i am guessing iam gonna need another battery how do u put 2 in?

95turbo gxe

iTrader: (25)

who ever is going to put your speakers and amp in should install that for you then.

Loco7

iTrader: (1)

my bad missed that part

Matt93SE

iTrader: (44)

Then you need to isolate the head unit and vehicle battery from the rest of the system. I worked on many competition SPL systems and could burp them all day at 175+ dB until their batteries were down to about 8 volts before recharging. the HU never shut off at all because we had the HU and vehicle power isolated from the rest of the system. the vehicle battery never dropped below about 11 volts and the HU never had issues with noise.

just hooking up a bunch of batteries in parallel doesn't do it sometimes. you have to do a bit of engineering on the electrical system before just throwing more batteries and caps at it.

also, what kind of caps were you using? If you say none, there's one big problem. If you say you were using the 40farad 'bat-caps', there's another problem. throw them away and buy a 6-pack of regular 1Farad electrolytic capacitors.

As I said before, I'm running 2500W RMS in my car with the stock alternator and ONE Optima red top battery. I have a 2F electrolytic cap in the back and 1/0 power cable from my battery to the amp rack. my lights BARELY dim when I have it cranked, even at idle with the lights and A/C running.

Proper design trumps throwing **** in the trunk anyday.

95turbo gxe

iTrader: (25)

I had three soundstream 1.5 caps wired in. If the alternator can put the amperage their then it will not work. How can you draw almost 200amp from a 90 alternator?

Matt93SE

iTrader: (44)

you don't draw 200 amps constantly. music is EXTREMELY transient in nature. that's also why you do SPL burps and not simply constant rumble. the burps keep the heat down in the voice coils of the subs because you're not drawing current more than a few seconds at a time.

With my system cranked during regular music-- even extremely bass-heavy music-- my system never pulled more than about 60amps constant (60A * 12V = 720W constant), even though I have blown 300A fuses when I cranked it for SPL burps at an IASCA competition.

you're equating the amp's maximum power output with the system's constant current draw. It just doesn't work like that, ESPECIALLY if your batteries are up to snuff.. A good 120A-H battery (i.e. Optima, Interstate, etc) can dump upwards of 1000A current for a short time (about 6-7 minutes) before dropping below a decent operating voltage.. If you have several wired in parallel, then you're looking at doubling or tripling that figure.

Then when the music stops, the alternator continues charging the battery..

alternator = constant 'slow' charge of ~100A.
music = extremely transient current draw with average of 40-50A at ear-bleeding volumes. maximum draw is of course dependent on total system output and efficiency, but usually those numbers are seen less than 5% of the system's running time... thus allowing the battery a lot of time to charge the system with 50A of current going directly back into the batteries.


Remember which one of us has the degree in electrical engineering, specializing in solid state electronics and power distribution.

vansskaterfreek

iTrader: (14)