mustbesatan

Hey all,

There seems to be a real lack of solid information about the potential for a stock alternator to handle aftermarket car audio, so I'm hoping to get some input.

The alt in my 2011 Elantra is just a little guy (90 amps) and I'm wondering what the maximum wattage which is SAFE (ie will not interfere with the normal functioning of the car, will not cause dimming lights, etc) to put into the car without changing the electrical system.

I guess the big unknown for me is how much the electrical system in the car uses now out of the 90 amps possible. I've read that the alternator should have enough output that having every power using component of the car on full blast should draw 75% of the maximum current. Does that have any basis in reality? If that's the case, is it safe to assume that under typical conditions, having a stereo system that could, say, draw 50% of the maximum current (in my case, about 700W) would be fairly safe, since I probably would never have the stereo on full blast with the AC, the high beams, both heated seats, etc etc etc.

Hopefully this is not too rambly a post. Thanks in advance for any input!

Loud Brown Kicker Colt

iTrader: (1)

battery capacity is a large thing to do with it too. if you pounded music it would load the alt most with bass hits. depending on the amount of bass, your alt might keep up to a thousand watts. With tones or sweeps, your alt probably won't keep up.
best way to determine consumtion is to check your voltage while @ your desired level. if it's below 12v you'll most likely need to upgrade your alt.
typically a 90amp alt will just keep up with all the standard accessories(wiper, heater,lights, defrost). there isn't alot left after that......

mustbesatan

I knew the answer wouldn't be that simple lol. Thanks though. It sounds to me, and this is what I had hoped was not the case, that I really won't know for sure what my car can handle until it's actually in the car and I can test it out.

Let me throw a couple of scenarios out there and maybe someone can help me make up my mind.

First off, I've chosen the components I have (and the store I am buying from) because I can get them for cost+10%, which on the JBL stuff is massively discounted.

Option 1: 2x JBL GTO1014 subs (350W RMS each) wired in a 2Ohm load to a JBL GTO7001 amp (700W RMS @2Ohms) I'm really thinking this will be too much wattage, not leaning towards this setup so much anymore.

Option 2: 1x JBL P1022 sub (400W RMS) wired in a 4Ohm load to the JBL GTO7001 amp (425W RMS @4Ohms) I LOVE the way this subwoofer looks, and looks are important to me, even though I'm just starting my setup. However, it is still a little up there on the wattage. This is probably as high as I should/would realistically go without knowing it will work.

Option 3: 2x some cheap Precision or other low end brand subs at 150W each with the JBL GTO3501 (360W RMS@ 2Ohms) This is nice because it's low power, and frankly I like the way two subwoofers looks much better than just one.


So... That's my internal debate at this point. Thanks a million to anyone willing to read through that and share an opinion.

Mr.DatSubishi

U can try to find a smaller pulley for your alt. It will spin faster than it wouldve otherwise at any engine speed. Helps make power without having to wind the engine out.

What about examples of real life situations? eg. I'm running 1350 RMS on stock ?amp alt, stock ?CCA rated battery and 2f cap. My voltage never drops below X @2000 rpm.

This is am example of my setup and I'll fill in the blanks when it's installed etc.

mohawkboom

for an SQ setup, most stock alternators with an extra battery will be way more than enough.. for unbalanced, bass heavy music. try it out, do the big 3 first, guality battery terminals, real copper wire. Some dimming is normal.

Real life situations always vary. I've ran many 2000Wrms+ setups and kept small stock alternators.... a lot depends on your musical tastes and listening levels.

nghtrdr

the best thing to do is find a freind with a amp clamp and connect it to the positive lead just off the batt. now start the engine and turn all accessories on ie, blower motor on high with ac on, rear defog, head lights on, ect. ect..the idea is to have as much on that u might have on at any given time. now see what the reading is. if ur alt can keep up which it should u will have a general idea of what all ur accessories will potentially use amperage wise.. now go to an auto electric place and ask to have ur alt load tested pay the small fee if any and u now know the potential of the alt.
with all this knowledge u will be able to know if u have any head room from the alt for a stereo system..

good luck
ps if u were in to i could connect my amp clamp and get the first ready for ya