[skiendog]

so, im wanting to put a big set of amps and subs in the trunk of the 98 E320. I put a set of (2) 12" 550watts (RMS) audiobahn subs and (2) 500watts (RMS) audiobahn amps in the back of my 94 E320 last year. I want to upgrade this go around. maybe... 3,000 watts rms?

will my alternator be able to handle it? i would, of course, use a capacitor with enough farads to handle that much power, and a batcap 400 (capable of 200 farads and 400 amps for up to 8 second.....less than that for a longer time) but i want to make sure that i wont slaughter my alternator, first. Someone suggested that if my E320 alternator was not able to handle it, i should look for an S class alternator, because they are made to run more electrical appliances in the car. Would this just swap in and out if i needed it?

 

[Diesel Benz]

The S-class alternator may not be equally powerful as one of the E-class alternators, depends on which models you compare. The E-class diesel would have an electric heating element at about 1700 to 1800 W. All the electronic appliances on an S-class would not consume that power (assuming starter motor is excluded).

I don't get your maths, a 200 farad capacitor charged to 12 volts, would reach 0 volts at 6 seconds if discharged with a constant 400 A current. I don't think you want to run your 3000 W amplifiers with 0 Volts (perhaps you should, saves your ears, perhpas the car too).

 

[rob13572468]

so, im wanting to put a big set of amps and subs in the trunk of the 98 E320. I put a set of (2) 12" 550watts (RMS) audiobahn subs and (2) 500watts (RMS) audiobahn amps in the back of my 94 E320 last year. I want to upgrade this go around. maybe... 3,000 watts rms?

will my alternator be able to handle it? i would, of course, use a capacitor with enough farads to handle that much power, and a batcap 400 (capable of 200 farads and 400 amps for up to 8 second.....less than that for a longer time) but i want to make sure that i wont slaughter my alternator, first. Someone suggested that if my E320 alternator was not able to handle it, i should look for an S class alternator, because they are made to run more electrical appliances in the car. Would this just swap in and out if i needed it?

you can do 3000 watts without upgrading the alternator *but* you will end up having to adhere to some guidelines to not blow things up. basically if you have a 3000 watt amp and it is class D then it will run ~80 percent efficient which puts your usage at 3600 watts or about 300 amps maximum current. that can be done if you have a capacitor as well as a seperate (preferably dry cell) battery in the trunk. the idea is to have the battery and cap as close to the amplifier as possible since 300 amps draw will create a voltage drop in any large length of power cable. wire the amp to the battery/cap with 1 GA and the battery to the front battery/alternator with a minimum 2 GA. this setup will allow you to run the system for a length of time at full blast depeleting the rear (reserve) battery. after a period of time you will need to turn it down and allow the battery to recharge. the idea is that normally you will not be blasting the system all of the time so normally you will not be pulling the 300 amps. keep in mind that since the stock alternator has a supply current of about 100 amps hot that it will take 3x as long to recharge as is does to drain the battery at full blast.

once you get above 2000 watts most systems use this setup, the reason being that building a reliable 300 amp charging system is difficult to do. you can however still upgrade to at least a 200 amp unit which is the largest alternator that will likely fit. also consider that if you use class A/B amplifiers then the efficiency goes down to around 50 percent resulting in a 6000 max draw or 500 amps.

 

[skiendog]

rob, i would be doing a class D for sure. I know about the second battery option, but i have never done an install on one. I will be getting the help of a certified MB mechanic who i know.

you guys rock, much thanks!

 

[cascade]

For a bit of perspective, the Police in some states will write you if your car Stereo sounds too loud at 50 feet or other distance when you are on the road. That goes double if your choice of music is rap/hip-hop and not Beethoven

Be sure to check the rules in your state before you proceed with this.

 

[skiendog]

im aware of all local laws concerning dB volume.

i am being told time and time again by guys in my club that i should NOT procede with this, even with an optima yellowtop in the trunk, if i am running a stock alternator. i really think that there might be some truth to this. i am being told that i need 175amp MINIMUM coming from my alternator to do this.

if i get my 115amp stock alternator rebuilt, what is the most that i can hope to get out of it when recoiled? is there a bigger mercedes S class (or diesel like you siad) that would have an alternator that could just swap right in? which models?