cleanSC400

I've searched and haven't been able to find anything on this subject.
to make a long story short i got a huge deal on 2 15" kicker L7's.
i will be running a hifonic's brutus series amp and push a full 1000watts rms to each of them depending on the condition of the stock electrical system until i can upgrade it.
I have heard these in a friends grand am on a no name amp and they were pretty violent. but they were also in a box that will be almost twice the size i will be using for my car and the box is ported, for my car the box will not be ported.
my question is... is it even safe to put this kind of power into our cars? even if i do upgrade the alternator and run a second battery to get the full 2000watts of power the gas tank in our cars is in the trunk... and I'm unsure if their are any risks in a setup like this.

another quick question... I've noticed i can buy a 200amp alternator on ebay for under $200 it has a one year warranty. is this legit? i know ebay sells mostly junk but a 200amp alternator sounds a lot better than the 145 amp thats offered on lextreme.

thanks in advance
-Allen

ArmyofOne

200 amps is what we use on our trucks in the military. They run Radio's, Screens, battery chargers, inverters, and its extreme overkill for us.

200A would likely either blow your fuses or burn up your harnesses. Thats quite a bit of power.

145 should be PLENTY for your application. I have run a 2000watt amp on far less.

Big Mack

iTrader: (1)

Bad info, mang. Just because you have 200A on tap doesn't mean you will draw 200A through any wiring/harnesses (save for a dead short, obviously). Your draw will not change, only the current available will change. That said, you should upgrade the factory power/ground cabling so that when you do have larger draws, which you will when running an amp that large, you are safe for your engine electronics and car computers, then ensure you are running (and fusing!!) the proper gauge wiring to that amp. Ground cable should be just as large as the +12V, and done to a secure location with a good solid connection.

As for running a 2Kw amp on less than 145A, not sure why you would ever want to do that. Even at 90% efficiency, a 2Kw amp is drawing 143A at full tilt. Maybe for short bursts, but even then, I would not do it. And I'm sure someone will chime in with "well, if he had extra batteries, etc..." the answer is no. Extra batteries do NOTHING if the charging system is not keeping up. They are simply another load.

Big Mack

cleanSC400

it makes sense, i would not have a second battery without upgrading the alternator.
i will be running all true 0 gauge wire for this setup and planned to at the minimum run the "big 3" upgrade in all true 0 gauge as well.
my plans next week i will be purchasing the amp, box and amp wiring kit as well as some extra 0 gauge wire. i will be soldering all connections as well. and yes for a wile i will be on the stock charging system as i am a broke college student

so do you guys this this setup will be ok? i dont want to hit some extreme low's and the gas tank blow up :\

big mack i was having some mis understanding what you were saying about the alternator. do you think the 145amp alternator will be all i will need? or would it be ok to consider the 200amp alternator on ebay? its significantly cheaper than the 145 on lextreme.

Big Mack

iTrader: (1)

I cannot vouch for the quality of either alternator, but if you're going to be running that much power, you need to make sure the electrical system can handle it. 145A is not enough, especially since these cars are very picky about voltage. Couple good bottom drops and the voltage will be sagging, one more and you could be looking at the car freaking out. Depending on how often you do play it loud, even 200A might not be enough. Old rule of thumb is that your alt can give up about 40% capacity to other things in the car. That said, that leaves you with 80A available on a 200A alt. Perfectly fine for most modest systems, but 2Kw is not really modest, now is it?

Big Mack

cleanSC400

hey you put it in good words their thanks mack!
i would not be against running just one of the L7's
to be honest maybe only running one L7 at 750-1000 watts rms seams more feasible what do you guys think?
would i be alright on stock charging system considering i still run all 0 gauge and do the "big 3" if running 750 watts rms to just one?

oh ya... electrical problems are no fun and this is my daily driver :\

mitsuguy

iTrader: (2)

In what world does an amp like that draw that much power continuously? Nothing against getting a bigger, better alternator, but Big Mack is taking it a little overboard... a class D Hifonics amp has a 200 amp fuse... that is MORE than absolute maximum draw of the amplifier, which will only happen for very very short periods of time... On top of that, alternators are not capable of supplying that much power as quickly as an amplifier is capable of needing it... You have to walk a fine line between battery capacity and alternator capacity... I've built competition systems, back when dB Drag Racing was just getting big and won my class 4 times at various venues... I never had more than the stock charging system and battery, had 1600 watts worth of power, but never needed anything more - you simply can't listen to a stereo that loud for very long, period, and batteries are more than capable of making up for the difference for short periods of time...

personally, if you are dead set on something that loud, do it, put a voltmeter on the electrical system in a few different places (fuse box, battery, other fuse box) and see what voltage drops to... I would bet it doesn't drop below 12 volts ever, and even if it did, probably for less than a measurable time period...

one more thing - why are you set on a sealed box? ported are much more efficient, can be run with less power, or louder with the same power...

Big Mack

iTrader: (1)

Hmm...please quote where I said "continuously." I said it could draw that much at full tilt, never once did I say it would do it all the time (and my math was a tad off, in that it could actually draw 158A when running at full tilt and 90% efficiency). When it does draw that much, however, it's a pretty significant amount of power to draw off an any charging system, and even if you're running at a steady 75A draw, which that amp is absolutely capable of doing continuously, the alternator will take a little bit of time to recharge the battery. Now, if you pound it quite a bit, you could easily kill a battery and the alternator would have no shot at keeping up. Granted, you'd be crazy to listen to it that loud all the time, but some people enjoy doing so.

I agree that you have to walk the line, and I've worked on several dB Drag cars myself, along with lots of experience with the competitors and system designers, but you're talking about people doing short bursts, not continuous music, too. I'm not saying that he will be ground pounding for hours and dropping absolute bottom constantly, but it's good to built a system that is practical for everyday long duration use, which dB Drag vehicles were not (typically) geared toward.

Big Mack

cleanSC400

for me its pretty much about headlight dimming.
I was looking at upgrading to the "big 3" with 0 gauge and running a 0 gauge kit.
but instead of running all that power as it would be nice to have the "baddest" system in town its not practical since this is my DD.
I've decided to run just one L7 with still a Hifonics brand amp but instead the HFI1500D
this setup will be more affordable.
I really want this to be my project and instead of investing a ton of money into the power thats going into it i was it to be over the top clean. so this is where i will put my money into.
as far as the alternator and my battery i figure i will run this setup in a custom built ported box (the reason i said sealed box before is because i could not find a ported box that would fix both subs that could fix in the trunk, at the same time i was set on purchasing a box instead of building).
can anyone tell me if 0 gauge is a requirement for this setup or would i be alright with 4 gauge.
ill be doing my purchasing on wed.

also I'm always interested in saving money as i want to put some wheels/tires/spacers/coilovers to give this SC an aggressive stance.
been working 60 hours a week at subway to buy this junk

as for my original main question i saw an SC with a beautiful setup on youtube it had 4 jl 10w3's and jl500/1 amps it was gorgeous and i know it is putting out more power than i'm going with now so i suppose i should be alright when it comes to the gas tank.

btw i made a mistake... i assumed these subs were 4ohm DVC but they are 2ohm DVC so their wont be any 1ohm'ed subs here. will be pushing 1000watt rms at 2 ohm to one sub

Kyle Harty

iTrader: (17)

If you are running one dual 2 ohm sub your options will be a 1 ohm or 4 ohm load. Find an amp that is optimized to run at either of those loads.

I'd run 0 gauge regardess of whether you "need" it right now or not, always better to have room to upgrade later if you decide to. The big 3 and the biggest alternator you can afford would be recommended as well. Listen to bigmack, he knows his stuff.

I wouldn't worry about the safety of the gas tank, they're built to withstand vibrations and that sort of thing.

CrimsonSC3

Im running 2300watts right now in my car... divided up I have 1500watts on my sub amp which is being ran at 1ohm and 800 watts for my 4 channel amp... I have a factory alternator however I do have a second battery located in my trunk, I have 4ga wire ran from the front to the rear battery and from the rear battery to the 2 amplifiers... I listen to it cranked up pretty loud and I have not noticed a power supply issue and my voltage stays in the 13s

note: and yes i did read macks thing about the battery so I had to laugh when i posted this... just saying this is what is working for me. i did have a 220amp stinger alternator in my other car. I did however have my alt rebuilt a few months ago too