Feeding a Beast

[Kirghiz]

I am thinking very seriously about upgrading my system again, and I am getting into power levels that i have never messed with before, thus I need some advice.

I'm looking at running (2) Elite.1's at 1 ohm driving (4) Elite 12D's, and (2) Elite.4's at probably 4 ohm, but I want to plan for 2 ohm. Basically it's about 10,000 watts rms. The Elite.1 has a current draw of 368 amps at 1 ohm, and the Elite.4 has a draw of 124 amps at 2 ohm. Let's just call the total current draw 1000 amps at rms power to keep it round.

My engine and body is favorable to multiple alternator setups, and I can get a triple alternator bracket. I'm looking at (2) 370 amp alternators to feed the amps, leaving the third spot for the OEM alternator to charge the vehicle. I'm thinking about the Stinger SPP2250 to be the system battery.

http://www.woofersetc.com/p-8802-spp225 ... ttery.aspx



My questions are:
A) Are those two alternators enough? (I tend to think so)
B) Will a single SPP2250 be enough, or would I need two batteries? (I have no idea, but installing two would be a problem)

[todd217]

alternators cant keep up with amperage changes like batteries can. i would think that one 370a alternator and 3 or 4 good batteries would be alot better than 2 or 3 alternators and 1 or 2 batteries.

[ttocs]

not sure I agree. If the alt can't keep up with the system or charging the battery then the battery will not save it for long. Put in as much as the budget allows for both...

[Stryker]

more Alternator than what the draw will be would be a start.with 2-370 amps alts you are still a big chunk away from your total draw of 1k
amps, slightly under would be ok i suppose, 260 under is no good IMO.
thats a ton of $$$ for charging alone. hope you have very deep pockets.
GL with this build. a build thread is needed.

[todd217]

sure its a balance but have 2 alternators and 1 battery is going to be too much strain on the battery. plus how long will full current be needed where a battery can supply a lot a amps for a brief period. how many of us that have or still run all a/b have an alternator that will cover full current demands. when i had my ms1000 i ran a stock alternator and a good battery and it was fine driving down the road even at 2ohm mono.

[brenzbmr@sb]

run the two alternators and buy enough batteries whos reserve minutes = the difference the alternators give you. so in your case 260 amps in reserve minutes. keep in mind though this car must be running and you will probably need to find out at what rpm these alternators are gonna put out all that juice at?

if you are gonna listen too music then one probably be okay as long as you can cover that 260 difference for the peak draws. The battery link you provided doesnt tell the reserve min but i assume its gonna be pretty high.

I would say if you are gonna be beating the shitt out of thsi system then buy the two alternators and at least two of those batteries you posted the link too. you will tax them fast (batts) if you are gonna play for long time at that draw on test tone type music even with car running since your alternators will cover 740amps plus have to charge the batteries when they get weak.

music = win
test tones = more batteries, i find that having reserve min in batteries to cover your total amperage draw works. 1000 amps in reserve min will take up lotsa realestate in car.

you could just install the two and one battery and test total amperage draw and check voltage and see how much stress at full tilt your battery goes through.
then compensate if need be.

good luck

[ttocs]

With a system that size if your alt isn't supplying the current it will not be playing for long nor loud off of a single battery, nor even two....

[Kirghiz]

I can actually get a quad bracket and run (3) 370 amp alternators if I had to, which it looks like I would. I don't have room for 2 batteries, so an extra alternator would be the way to go. That would be roughly $3500 in charging, and that blows the budget all to hell.

Back to the drawing board......

[ttocs]

if that didn't include the wires, dist blocks and all the accessories it will be a bit more then that. would love to dyno a car before/after that upgrade too see how much hp the alts literally suck up. Its a hell of a dream man but it is a HELL of a dream.

[Kirghiz]

Well, the Elite.1 only pulls 194 amps at 2 ohms according to the tech sheet, so, two of them at 2 ohms, plus the Elite.4's would be about 650 amps. That would work easily off of 2 alts and 1 batt. I could go with a pair of 300 amp alternators instead of 370's, and that would save me about $500 as well. The reality is that the Elite 12 will basically hit the same volume with 1400 watts on it as it will with 2000 watts, and it'll probably sound better since the THD is 4 times as high at 1 ohm as it is at 2 ohm. When you have 4 Elite 12's ported, I very seriously doubt you are going to miss two or three DB. This sounds like a much better plan all the way around.

Now I just need to wait for Q3 for the dual 2 ohm version of the Elite 12 to come out.

[Kirghiz]

Another question......

Do alternators have to match? I already have a 300 amp alternator that is a couple years old, and most assuredly made by someone other than who I would order the second one from (I bought it used, don't know who made it). Could I get away with just ordering the 3 way bracket and 1 300 amp alt (and belt, wire, and whatnot), or would I have to get two 300 amp alts to make them match, and sell the one I've got? Not sure if that makes a difference or not with alternators. On some things it makes a difference, and not others.....

[ttocs]

interesting question as I have never known anyone to use one old one new but I would hazard a guess that if they are not matched that it could a bit of a loss.

[zeropoint0.5]

i wish european cars had space to put in an extra HO alternator


Does anyone know a solution/brand for german cars

[ttocs]

could put a gas powered generator in the trunk.

[Kirghiz]

would love to dyno a car before/after that upgrade too see how much hp the alts literally suck up.

It would be interesting. I was looking at a 300 amp alternator where they had graphs, outputs, and the whole nine yards. They had measured the power output of this alternator at 4,487 watts. Theoretically, if you look at the alternator as a DC motor (albeit in reverse) and use the mechanical horsepower to watts conversion formula (745.69 watts = 1 HP), then in theory this alternator would be sucking up 5.9 HP. Two of them would be roughly 12 HP. Of course that doesn't take into account any loss from the added pulleys and that sort of thing, so I would expect it to be a loss of about 15-20 HP give or take, in theory.

The stock 2012 5.3L Vortec engine makes about 315 HP, so 15-20 HP isn't a huge deal. I could chip it and get that back if it turns out that I miss it later on.

[brenzbmr@sb]

what is the goal of your system?

[Kirghiz]

I always like a very clean sounding system, I have that now and this upgrade would continue to be that, but every once in a while I long for a system that can turn me into jelly.

[Mr. Wild]

15-20hp doesn't sound like much when compared to 315hp, but do the math.

15hp at 700rpm (idling) equals 150Nm of torque, so you're lucky to have a big V8. A normal 2 litre engine would stall. And I'm willing to bet that alternator belt slip is a big issue here too.

15hp at 2100rpm (cruising) equals 50Nm of torque which is probably quite noticeable too, but so is 10,000 watts of stereo

[Kirghiz]

you're lucky to have a big V8.

It has nothing to do with luck. I had to have a truck, but when I decided it was time to get a new one, I decided I was going to get the best one to do a system in. I then researched to find out which one had the most space under the seat, and which one was the easiest to do charging upgrades to. What I found is that there is a damn good reason why all the big SPL systems are found in Hummers, Escalades, Tahoes, Trailblazers, and Suburbans, and it isn't only because they have a ton of cargo space. They all use the 5.3L and 6.0L GM engines, both of which take the same alternator, and they are common enough that many of the alternator companies cater to those models with both alternators and multiple alternator brackets. Where you'd have to have these things custom made for another engine, you can just go online and order them like you would speakers for this engine. Not all engines are created equal when it comes to car audio, not even all the V8's.

In a lot of cases the vehicle dictates what you can and can't do to the system, and I went out of my way to make sure I had all my options open. When I started out I was hoping not to have to upgrade the alternator at all, but I wanted it as an option if I needed. What started out as a simple system with a 5 channel amp and single sub has evolved into this. I just hope I stop before I decide to do a blow through next year. lol

[LowandLoud]

Blow through!, blow through!

J/K,

LL

[zztunnell]

I think you can keep your existing alternator in the mix. As long as it works. It works.

Even if you have 3 new alternators built the same way. All 3 can put out the same,but I doubt all 3 would put out the 'exact' same all the way through the rpm range.

All alternators matching would look cooler and 'might' be better from a durability stand point. That being said,just because its new doesnt means its gonna last any longer. You could buy 3 alts and one could go out on you the next day or 6 six years later.

I highly recommend Mechman Alternators in Knoxville they have been a HUGE help in getting me pointed in the right direction. Not to mention after the full 2 year warranty theyll still fix any of their alternators for just the cost of the parts. Ok enough advertising,lol.

Side note. Do you have any room under your truck on the inside or outside of your framerails for a small 2or3 battery rack? Theres usually a lot of real estate under a truck.

[Kirghiz]

I was thinking that if I had to do multiple batteries I'd put them in the bed. I have a roll-n-lock bed cover, and it has a "crank housing" at the front of the bed, and there is enough space under it for about four batteries, but running the cable might be a trick. Probably just going to get the biggest single battery I can and go overkill on the alternators.