BrentD86

Hi, im looking into putting a subwoofer or two in my trunk and If I do so I was wondering how big of an amp can the stock alternator handle without damaging it. I'm guessing a 1000W amp would require a H.O. alternator just wondering what the stock one can handle so I can shop for subs based on their rms.

Socket7

The stock alternator has an 100 amp output.

Watts = Volts * Amps

So assuming it's outputting 13V, it has a theoretical output of 1300 watts, not accounting for losses due to mechanical inefficiency

Keep in mind that the draw of your amp is usually going to be considerably less then the RMS listed on the amp. Unless you like going deaf.

firebirdude

iTrader: (3)

I believe we have several people on here running 1000WRMS on the stock alt.

Huey52

iTrader: (2)

This discussion is analogous to household wattage/amperage. Most of us have 100 amp or better service, but we don't use anywhere near the potential wattage on a continuous basis.

As Socket7 indicates, unless you're going for deafening sound levels you should be fine on the stock alternator.

btw: I prefer P = IE, and PIE

BlueKnight

I am running well over 1000WRMS in my car. There are two things to keep in mind ...

1. The battery will provide more power than the alternator but will recharge when you are not blaring the music.
2. Use a capacitor on your subwoofer amp to keep from frying your battery, etc. When you push serious base it will consume some massive power and strain the battery. A cap will help buffer the spikes in power consumption.

Jedi54

iTrader: (7)

I'm running a 1400WRMS amp, my alternator lasted until about 55,000 miles.
I replaced it with another OEM, no problems...

BrentD86

thanks thats why I was asking I remember when I had my tacoma I only ran like a 600W Amp and killed my alternator in like 30,000 miles. Also I have heard that running capacitors is actually bad and draws too much harder on the alternator. See I would like to get an Alpine type x 10 and the alpine 1000w amp I just wanted to know if I had to worry about replacing the alt.

Socket7

Capacitors are not any harder on your charging system once they reach full charge. Theoretically, they should keep the load on the charging system more stable when your amp is hitting hard. If they improve sound, or actually increase the life of an alternator is something that is hard to quantify due to the variables involved. I have my capacitor because it has a nifty LED display I can use to check my battery voltage, and it looks cool in my trunk.

Since the amp is what actually uses power, once the cap is charged, the only load it can place on the charging system is to recharge what current has been drained from it by the amp. It can't really consume power on it's own.

Jedi54

iTrader: (7)

+1 on pretty Capacitor

nycgps

iTrader: (1)

where and how much u got it from ?

it looks pretty ... Ahh ... nice and blue ...

show off. psssst :P

BlueKnight

I run a monster cap

http://www.monstercable.com/mpc/prod...&section=three

Socket7

Mines a Boss, got it for 30 bucks in the "returned goods" section of crutchfield.com.

SiLVeRE8

iTrader: (8)

I was running an 800 watt amp with a capacitor and my alternator blew after 1.5 years for some reason. good thing I had warranty

Huey52

iTrader: (2)

Capacitors are always a good idea. They smooth out the clipping and promote a more efficient power factor. That's why they're on every substation of the power grid in the country and in older infrastructures are still on the outlying poles. As Socket7 indicates, after the initial charge they're no harder on the alternator.