6G Celicas Forums

i just put a new sound system in and my alternator cant cut it. do i need a new one and if so what type

This post has been edited by bosch8711: Jan 23, 2005 - 9:28 PM

i have 2 jl 12w3s with a kenwood amp and i have had 0 dimming. the stock alternator is beefy enough for most audio applications

with the setup ur running i dont see how you could draw enough power to cause any problems. you sure you dont have a bad alternator or a bad battery. maybe try hooking up a voltmeter and see how the power draw is

This post has been edited by DamDirtyApes: Jan 23, 2005 - 10:13 PM

i threw on 80 amp one from a camry in mine. it bolts right up no mods needed.

well you want an alt that will supply enough for your stereo and everything else ofcourse.... id say a 160amp alt will do just fine... not sure where to get em for Celica's.... but im sure Iraggi can make you one...

oh and nice avatar, i have the same one on another board

This post has been edited by Scarrell: Jan 23, 2005 - 10:31 PM

how much does the stock celica alternator put out. wouldent that be the same as the camry one . they are both 5sfes. (unles u got it from a newer model or a v6)

i have my high beams on, subs pounding and ill use my sunroof and my lights DONT DIM. and my amp provides alot of power for my subs

my lights used to dim before i put in my 2.5farad cap... my battery went dead when i was stupid enough to play the system kina loud without my car on for 45 min or so though

Alternators come and go. I've had to replace one in every car I've owned and two in one car. Sometimes they work forever, sometimes turning your power windows on will destroy them. However, if you are a serious stereo guy, I wouldn't replace with stock, but with a high output alternator. Search google.

-Ti

I was thinking my alkt is going up to. i have a nice stero, but i know its not drawing enough. But recently i switched to a yellow top batt, cause mine died. Then I noticed when im driving then slow down, let off the gas then hit the break my lights dim, and thats with the stero down. Any idears??

a cap. wont help after awhile... you dont really need one, but then again they can do a little for you, just one of those "if you want to use one" type of things... the only Real way to stop dimming is getting a highoutput alt. and ofcourse upgrading the wiring when you do this(a Must really) and getting a good battery is always a plus(i.e. Optima yellow/red top.) even after getting all of this, dimming can still occur... just how life is..

You kinda have that backwords. A Cap will help Dimming. Thats what it is designed for. So its not puttin quick deep draws from your batt or alt. I wouldnt bother doing an high-output alt, unless u have one crazy setup or u already need to replace it.

http://www.bcae1.com/capacitr.htm <-- that will explain them pretty good.. but heres what i think:

A capacitor WILL:
-Stiffen voltage rails. If you experience very brief, momentary periods of high current demand that cause the electrical system to falter only at these rare, peak draw times, then a capacitor will supply the additional current needed (when bass hits) to keep your voltage rails stiff, and prevent damage to the car or audio equipment.
-Increase response times for musical accuracy by reducing delay caused by transient response times between current demands from the amplifier, and response to this by the electrical system. In other words, your subs will respond more quickly, because they don't have to wait for the alternator to supply additional current at the moment of demand. Amplifiers have to provide a very dynamic and quick response many times. A capacitor can assist in this if the rest of the charging system is up to par.

A capacitor will NOT:
-replace the need for a larger, high-output alternator and/or a deep-cycle battery or batteries.
If your electrical system is inadequate, the ONLY way to fix this, and again I repeat, the ONLY WAY to fix this, is to replace the alternator. This is the SOLE source of electrical current for your car when the motor is running.
When the motor is turned off, the battery then becomes your source of electricity.
When the battery is run down, and when the capacitor(s) is/are depleted, the alternator has to work even harder in order to supply current to the car, the audio system, and also to recharge the capacitor(s) (which deplete very quickly) as well as recharge the car's battery(ies).
So by adding a capacitor to try taking the place of a high-output alternator, you are actually causing more work for your alternator, and causing even more damage to that stock alternator.
-make your system magically sound 10 times better.

Many people believe that a capacitor adds NO real benefit to an audio system, and this is why you never see before and after demonstrations, or factory capacitor company vehicles at competition events.
A capacitor does have it's uses, but it is not a magical fix for a lacking electrical system.

To calculate the capacitance needed for your system, you will need to find the peak or max power ratings of your amplifiers, and add those together. This is the only time peak amplifier power ratings are even remotely useful, since a capacitor is only used to cover very brief peak demands, and not cover for the continuous amplifier demands.
Take the peak power total and figure 1 farad of capacitance for every 1000 watts of power.

ive also covered the altenator once before, guess ill copy it and paste in this post. but yet again http://www.bcae1.com/chargin2.htm covers it good also but:

"Do I need a high output alternator or just a capacitor?"
If you want a killer system, you may think that all you need are big amplifiers and huge speakers. Not so! Adding a bunch of car audio components to your vehicle without the proper charging system may lead you to disappointment, distortion and damaged equipment.

Let's say you install a 1,200 watt amplifier in your ride. Your rides charging system must produce enough electrical current to run the amplifier. Now how do you know how much current is needed? Simple: divide the RMS power rating of the amplifier by the amount of voltage your cars electrical system will produce then add in amplifier inefficiency based on amplifier class.

Most vehicle electrical systems are 12.5VDC at idle, and between 13.8 and 14.4VDC above about 900rpm but we use 12 volts as the standard for these calculations, so 1,200 watts divided by 12 volts equals 100 Amperes of current. If this is a class D amplifier, it'll be ~80% efficiend, so we'll add 20% of 100A to the total, and we get about 120A of current demand continuously at peak amp output. This means that the electrical system of the vehicle will need to produce an extra 120 Amperes of electrical current to power your amplifier and subwoofer at peak levels. Keep in mind that the factory electrical system is designed to produce enough charging power (alternator and battery) for the vehicle's stock equipment, and was not designed to accomodate high-powered audio systems.

The biggest mistake made by consumers and (some) installers is failing to beef up the charging system to handle the extra load of the audio system. First, you need to understand how the electrical system operates. This must be one of the most mis-understood systems of the entire vehicle, so here's a brief summary:

Turning the ignition key begins the process of cranking the motor. The battery supplies the power to get things started. Once the engine is running, the electrical burden is shifted over to the alternator. The alternator uses the engine's mechanical power to produce electrical (AC) current. The AC current is passed through a rectifier and changed to DC current which is then sent through a voltage regulator to smooth out and set the voltage rails for the car . The alternator also has the duty of recharging the battery after starting the vehicle by providing a forward bias voltage higher than that which the battery produces on it's own.

Everything works perfectly so long as the power requirements of the vehicle do not exceed the capabilities of the alternator. If the peak output is surpassed due to excessive load, then power will be pulled from the battery. If the alternator and battery combined cannot meet the demand, then the vehicle's voltage rails, and subsequently the electrical devices are diminished (dimming lights, spark plug misfires, audio distortion and amplifier clipping, or even the car stalling.)

The first place to look to determine if your charging system is up to the task is the alternator itself. If possible, look for the HOT RATING on the alternator. IF you can't see it easily, call a local auto-parts store or car dealership and ask them to look up the stock alternator size, or rating for your vehicle. The hot rating will tell you the amount of power the alternator will produce once the engine reaches it's operating temperature (this is a lower rating than the cold rating). I suggest using your stock alternator unless you experience problems. That's how you know if you need to upgrade, since there is no concrete way to tell if a stock alternator has enough reserve to handle your additional burdens. Now, if you do need a new and larger alternator, after finding the stock rating, then allow your alternator about 10 Amperes credit or buffer area.

As a note, when calculating your required current for your audio system, this is an easy way to do it:

1: calculate the total RMS wattage of your system based on how the amplifiers are wired (2 Ohm load, 4 Ohm load etc)

2: take that total RMS rating, and divide by 12.

3: add 20% for class D and T or 40% for class AB.

4: add amplifier totals together for a combined measurement.

This is how many Amperes your audio system will require in addition to what your car already needs (stock alternator rating) at full output.

ok my amp pushes 500 watts and i got a 50x4 watt head unit and evrything dims and it did it b4 i got the system

ok my amp pushes 500 watts and i got a 50x4 watt head unit and evrything dims and it did it b4 i got the system

the stock gt alt is supposed to be rated at 70 amps. the camry one on the v6 is rated at 80 amps. it bolts right up to the celi it's like it was made to be in there.