Would the alternator blowup?

[flynhigh2007]

Hey guys well just wanted to know since I am going to get a new sub and amp for the car I'm concerned about the alternator. I'm planning on getting a 500W mono amp, will the golfs alternator stuff up if i install it or will it be able to handle it etc?

What have you guys done to stop it from stuffing up? New battery, new alternator etc?
Any help would be great

[Jmac]

Mate you could upgrade to a 90amp for tha application or if you go bigger a 120 amp. Just remember in some amps if the voltage supply goes below 12v they can overheat. There are a few calculations you can do to work out the right Alt to buy. If you are going to have lots of CarPark noise then you will have to think about a bigger battey too
CHeers

[Spyda]

What golf do you have mate and is that 500RMS watts or peak watts?

Either way you alt wont blow up. If your system is drawing to much power then your lights will dim with the music. If the draw is to heavy your amp will cut out to save itself, then it will over heat and then it will get damaged.

If you have a new goof then you should be ok, if you have a mk1 or 2 then you should look in to a 90amp alt or a high performance battery.

[flynhigh2007]

i've got a 2.0l mk4 golf. The amp im looking at is and xplod X1MS

http://www.sony.com.au/xplod/catalog/product.jsp?categoryId=22002

Output Power

CEA Rating: 280W x 1
DIN 45500 Rating (@ 14 V, THD 0.5 %)

4 ohm: 1 x 280W
2 ohm: 1 x 500W
Rated/THD (@ 14.4 V, 20 Hz - 20 kHz)

4 ohm: 1 x 290W / 0.2% (14.4V, 20 - 300Hz)
2 ohm: 1 x 500W / 1.0% (14.4V, 100Hz)
Maximum (@ 14.4 V)

4 ohm: 1 x 600W
2 ohm: 1 x 900W


. So will the alternator last, or will i have to change it for a new one, based on these stats?

[flynhigh2007]

I'm not thinking about a lot of car park noise, just buying a subwoofer and thats the only amp that can power the subwoofer im getting. Just to listen to music while in the car nothing big.
Which alternator should i upgrade to, and how much will i be looking at?


cheers

[Spyda]

You dont need to upgrade anything.
You should be fine with a good battery and some 4 gauge wire. Your alt is 90amps and thats plenty.

My mate has that amp and i have to say that it pretty good coming from sony, compact and packs a decent punch.

If your alt and battery cant handle it then your amp will go a long time before anything happens to your alt.

Its only 500wats so nothing to really worry about.

oh and if you are dead set on upgrading your alt then a vr6 alt will bolt on with 120amps but it will set you about about $250.

Like i said you don't need it.

[flynhigh2007]

hey so the stock altenator is 90amps? That will be enough to run the 500w amp without the light dimming or any electrical problems?
Just want to make sure thats all, dont want to buy the amp and insttall it next thing i know is i have a crash cause my car blacks out.

The 120alternator from the vr6 where can i get them? Wreckers im assuming?


Also you friend you said is running the same amp, is he running it in the same mk4 golf and he hasnt changed nothing or is he running it in another car?

cheers

[flynhigh2007]

Sorry forgot to ask because im dont know much about car audio and electronics. How do you know based on the amps stats and performance whether or not the alternator can support it?
Also how do you know based on the power and stats of a subwoofe which amp you need to power it?

If you get what i mean.. just want to learn this stuff thats all

[Jmac]

Yes the 90 amp should be ok mate and for some of the bass thumps you should look at getting a capacitor too mate

[flynhigh2007]

thanks a lot for your help guys

[MattyT]

No problem, glad to help

Only kidding... but does the vr6 come with a 120 amp alt??

[Mr ©harisma]

Usually for the dancing headlights:
- Upgrade your factory earths
- upgrade your battery
- add a cap if all else fails

[brentondm]

looking at the sony website that the OP linked to. it already has the draw figure.

Current drain (@ Rated Power - 4Ω): 30 Amps (at 4 ohm)

so 500W / 30 amps gives me a reading of 16.666666 volts.

a more modest voltage of 14.4 volts, from 500W gives us 34.722 AMPS, how frequently will you be driving your amp at full duty, i honestly believe you will be fine considering the following.

your 90 amp alternator in good condition is a 3 phase charger that generates 3 phase AC that is passed through a bridge rectifier to somewhat deliver a DC sine.

As long as you are confident that your alternator + charging cable + ground cables are in tip top condition you will be able to run your 30AMP AMP at full duty, you may need some cooling on it but your alternator should cope.

if you loose one of the phases you'll only be delivering 60 max potential amps from the alternator, this may occur after you start using your new amp under load.

it may not be apparent, that you have lost a charging phase and the only way to fully test this is to remove the alternator and get a full field test done on it.

a basic way is to start the car with a multimeter on it and monitor the voltage as you turn things on, a failing alternator will start to suffer voltage droop.

CAUTION: if you make lots of short trips which doesn't give long charge times and deep cycling due to the starter motor, it will lead to quicker battery death.

the more load you put on the alternator, the harder it has to work, it will fail eventually, these are things to be aware of.

charging system tests

RMS values times 1.414 equals the Peak value.
Peak to Peak is twice this.
7.07 volts RMS times 1.414 and then doubled is 20 volts, the Peak to Peak value.

Peak values times 0.707 gives the RMS value.
Don't forget that Peak is half the Peak to Peak.
20 volts Peak to Peak is 10 volts Peak.  10 volts Peak times 0.707 equals 7.07 volts RMS.