Hi just installed a very choice car system...

Im not running, Alpine deck with fancy lights etc...Clarion 2 channel amp and a Rockford mono amp...I was wondering what sort of effect does the voltages etc have on the car batteries, power,fuel consumption, performance or any adverse effects elsewhere..or if none at all..?

i dont think it would be affecting anything majour, its only drawing a few hundred watts (if that) from the altenator once the engine is on.. considering the car is producing power in the thpusands of watts id say it isnt doing anything at all..

but maybe im wrong

will drain ur battery if u pump it up for a while with the engine off too much id imagine..

Obviously there is an increased load on the battery and alternator but if your battery is of good quality and your alternator in good condition you'll be fine. :)

It doesn't effect the motor overly. Your sparks might be slightly weaker but this wouldn't be noticeable with the system you have outlined. :)

mine started 2 idle a little lower than it usually did b4, especially with the lights on, but i just ajusted it so it was higher, no biggy.

One way you can think about it is like this...

The alternator is (essentially) just an electric motor. When you spin an electric motor, you get a voltage drop across it's terminals (electricity).
The more current you draw from the alternator, the harder it is to spin, so your engine is working harder just to supply the alternator.

Some of you guys are running up to 2000Watt amps - thats 2kW. You can basically directly subtract that from your engine power when you have your stazza cranked.

-Dan

One way you can think about it is like this...

The alternator is (essentially) just an electric motor. When you spin an electric motor, you get a voltage drop across it's terminals (electricity).
The more current you draw from the alternator, the harder it is to spin, so your engine is working harder just to supply the alternator.

Some of you guys are running up to 2000Watt amps - thats 2kW. You can basically directly subtract that from your engine power when you have your stazza cranked.

-Dan

But the amp is Amplifying that current, its not drawing 2kw from the alternator.. its drawing out the same amount of power then increasing it.

as is my understanding

This is what my mechanic told me (he has worked on magnas ever since they first came out hehe).
With amps that hook directly onto the battery, they will only affect the car on idle. You may find you idle slightly less or a TINY bit rougher. This is with the stereo fairly loud. He said that when the car is running and moving (ie. not idling) the alternator does most of the work for the engine, so any power you drain from the battery doesn't really affect the car's performance while in motion.
He told me this cuz he saw my big arse cable running off the battery and asked me if my car ever seemed like it was going to stall when idle (cuz my idle was VERY low, up loud it actually has :S, but my idle is slightly more now so its all good :)).

I'm pretty sure thats what he said, hopefully i made some sense :).

Well there you go. So in conclusion. No, no amount of stereo/speakers will affect your cars performance. Except for its weight.

OK
I actually tested this and heres what happened -
I have an 800 watt amp hooked into the battery
When the HU is at 30% volume(not dB but volume control, you know what i mean!) the car is steady at 600 rpm. When i turn it up to 40-50% it drops to about 575 rpm, then up to 60% it drops down to around 525-550 rpm. I didn't go any higher cuz at 60% your head hurts and its damn loud, plus i was sitting at the traffic lights so i didn't wanna piss people off next to me :P. ALSO, i've noticed taking off when the stereo up loud, it hesitates for about .01 seconds, hardly noticable.

The most noticible effect on performance will come from the added weight of the gear (subwoofer box etc.) some installs it is like another person in the car (60kg)

Cheers
Heath Young

unless you are running big big power, and im talking compeition type setups, you wont notice any difference at all, except maybe light dim etc at idle when the stereo is cranking

if you are all worried about it, go buy an optima yellow top battery, it will solve all you problems :)
well worth the extra expense

Yeah, my boot is like having a couple of dudes in your car so a bit of jetlag