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-   -   85 amps (https://www.caraudioforumz.com/car-audio-technical-discussions-70/85-amps-117641/)

Sikk Nation 10-16-2008 07:07 PM

yes you can do it. upgrade your BIG 3. run either 2 guage power wire, or a pair of 4 guage. You will be fine, but you will experience some dimming when your cranking it up.

Amplifiers only draw their max amperage numbers with a sine wave at 100% output.

Music at most is a 25% dynamic load. when canking it you'll still be pulling the equivalent of around 30 amps constant. Which is like driving around trying to start your car all the time(on a warm day)

JohnVroom 10-16-2008 08:18 PM

The stock 85 amp alt will power the HU, amps, processors, head lights, rear window defroster, any electrical gizmo's that came with the car (CC, satellite, heated seats) and the HVAC fan. basically there isn't much electrical power available if all the stuff in the car is turned on so good luck trying to light a cigarette. you will be close to overload though so don't get carried away.

denis 10-16-2008 09:33 PM


Originally Posted by Sikk Nation (Post 408677)
yes you can do it. upgrade your BIG 3. run either 2 guage power wire, or a pair of 4 guage. You will be fine, but you will experience some dimming when your cranking it up.

Amplifiers only draw their max amperage numbers with a sine wave at 100% output.

Music at most is a 25% dynamic load. when canking it you'll still be pulling the equivalent of around 30 amps constant. Which is like driving around trying to start your car all the time(on a warm day)

im runing crapy 8 gauge by piramid with only the p450.2 pushing the 10" sub right now (have not installed the 4 ch amp or speakers yet) i alrady got a metra raptor 4 gauge amp kit from my buddy for next to nothing, and were planing on installing that, would single 4 gauge be good, or should i also leave the 8 gauge just in case?

Sikk Nation 10-16-2008 09:41 PM

I mean real 4 guage. the Metra raptor kit is actually 6 guage with more rubber. wiring is the most important thing if you want to run big power. buy some brand name 4 guage, tha actually is 4 guae nd not 6 or 8 guage with a really thick ruber jacket.

godzilla1978 10-17-2008 02:07 AM


Originally Posted by JohnVroom (Post 408693)
The stock 85 amp alt will power the HU, amps, processors, head lights, rear window defroster, any electrical gizmo's that came with the car (CC, satellite, heated seats) and the HVAC fan. basically there isn't much electrical power available if all the stuff in the car is turned on so good luck trying to light a cigarette. you will be close to overload though so don't get carried away.

John vroom is right but you forgot one of the most important things, the ignition system! An 85 amp alternator will not last very long with that kind of load. A cap will not help at all either. It's even worse if your a short trip(less than 10k) driver. Your alt spends most of it's time trying to charge the battery from starting the car. If your running a system, and lets say the heat and the lights your car will steal power from the battery to run everything. That will kill the battery which in turn will kill the alt which in turn will kill your car and your system, cause you won't be able to listen to it!

Sikk Nation 10-17-2008 02:10 AM

In theory it will not work. but there's been civics corollas and tercels with 60-70 amp alternators runing around since the early 2000's running 1200+wrms and surviving. for long term sustained cranking it, it will drain out the battery. but how many pople actually do that?. other than for the frst 2-3 weeks of your first major sound system?.

it'll be fine. if he goes through a battery a year it's not too bad.

godzilla1978 10-17-2008 02:21 AM


Originally Posted by Sikk Nation (Post 408918)
In theory it will not work. but there's been civics corollas and tercels with 60-70 amp alternators runing around since the early 2000's running 1200+wrms and surviving. for long term sustained cranking it, it will drain out the battery. but how many pople actually do that?. other than for the frst 2-3 weeks of your first major sound system?.

it'll be fine. if he goes through a battery a year it's not too bad.

I had a 70 amp alt in mine an it took about 6 months for it to die. Besides for the price of a new battery every year or for one year for that matter it's cheaper to get a new alt. I had mine rebuilt to 140amps for 200 bucks. That's not that much more than the price of a battery. Plus the added peace of mind that my car will start and my system will continue to pound for years to come. This is one of those cases where an once of prevention solves a pound of problems applies.

BIGEVIL 10-17-2008 12:57 PM

[QUOTE][The stock 85 amp alt will power the HU, amps, processors, head lights, rear window defroster, any electrical gizmo's that came with the car (CC, satellite, heated seats) and the HVAC fan. basically there isn't much electrical power available if all the stuff in the car is turned on so good luck trying to light a cigarette. you will be close to overload though so don't get carried away.
/QUOTE]

True, but how often are all those on at the same time?


That will kill the battery which in turn will kill the alt which in turn will kill your car and your system,
Kill your car? Probably not. Usually when an alt fails, it is because of worn brushes. About $9 and 1 hour fix.

I originally got in to car audio in the 80's. My Toyota p/u had a 40 amp alt. It used to be a big deal to have 1,000 watts. A set of brushes 2-3 time a year and I was good to go.

TragicMagic 10-17-2008 01:05 PM

Alright, lets say that for whatever reason the amplifiers decided to pull 100 amperes. And he's got a 100amp fuse at the battery, to coincide with what the amplifier specifications suggest. What happens to his 85 ampere alternator? Anything, or does the lack of necessary current just mean the the amplifier won't get the power it needs and his sound goes for a dump, and his lights go dim.

Hell, I've had my 2002 Elantra for six years. I couldn't even tell you what my alternator produces. I have heard that cars with manual transmission are easier on the electrical system. Any truth to that? I assume so, must take a little power for an automatic to function all the time.

denis 10-17-2008 01:18 PM

the best i can do is run the crappy 4 gauge on top of my crappy 8 gauge that i have now because everything is done on a student budget.


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