Hey guys, im in the market for a new alt, i stopped at a local alt rebuilder and he said there isnt much he can do with it to make it last longer becuase of the horrible rectifiyers(sp) that are made.

What can i do to get more life out of my alt with the extreme draws i am going to put on it? Id like to get a 140 amp alt and put a smaller pulley on it, that should get more power out at idle/lower rpms?

Im lost as what to do



this is going in a 87 ta with ac, p/s, smog pump and is v-belt

 

CAPACITOR!!! Go to Crutchfield.com and look for them if you don't know what I'm talking about, I think they still sell some. These store up an electrical charge, and when the bass hits, it draws the power from the capacitor, not the alternator, thereby saving your alt. A must for anyone with a powerful stereo system in their car. Just don't short the terminals of a fully charged cap!

 

Not sure what he means by rectifiers. An electrolytic capacitor is a good idea, it will provide a smoothing effect for the DC thus reducing large transient spikes that occur with high power amp output transistors. A large enough voltage spike could damage the rectifier diode junctions, but a larger alt will not solve that problem. With a large load it is probably a good idea to bump up to a 140 if you are going to do a replacement.

 

The capacitor idea is sound...but in my experience the very 1st thing to do is to get a high capacity battery like the Optima.

A very good friend of mine has competed in the IASCA (sp?) competitions in the five state area and his competition car was a 93 Formula. He had the caps and was replacing alternators...then he decided on a good battery setup (dual Optimas) and a charging isolator.

You don't need dual batteries just yet... but definitely make sure you have a high capacity battery that will handle the load. The system will draw the current from the best, most available source and if your ground/power connections to the battery aren't great, then it will try to draw power from the alternator first.

 

he meant the soddering points on the rectifiyer, at high temps they melt or break

do you think i should go with having him build a 140amp alt and just take my chances? i will be upgrading battery wires and such,
or is there a different kind of alt that will fit under my hood, from a different car that can handle more abuse when built up?

 

What do you mean you are going to be upgrading battery wires and such?

What do you have now for wiring?

A 140 amp alternator will work fine with your setup with the proper wiring, battery and a cap or two...

 

the ground and power from the battery, i believe they came with 8 gauge?? from the factory and im going down to the lowest i can find

 

What do you have for ground wires/straps right now? In your whole system...

 

my system right now has 4 gauge going into a dis block then 4ga going into each amp, 4ga for grounds too

 

Be more specific about the grounds...they are just as important as the positive power wires...

Also, you just have a stock wire from the alt to the batt?

 

you can get a stock alternator for a police car, they are more amps than any other stock car. and they will fit a comaro. or i have heard of people putting two alternators in there car. i think that the cop car alternator is 140 amps, but it may not be, but i know that it is more amps than stock, because the need more for all the electronics that the have in there cars.
later,
Ryan

 

You don't need two alternators...it is just that simple...

Keep in mind that the primary source of power is the battery...end of story...the alternator basically makes sure that the battery stays charged...

Why? Because if you force your alternator to carry the brunt of the work (with only a 140 amp duty capacity), it will fail...The battery should have at least a 600 CCA capacity...preferably larger (750-1000) for serious stereo systems...

I have an interest in stereo stuff and my friend is the install manager of an Audio King store (high end stuff) here in Mpls...I have seen some $50K competition systems...usually what they do is have multiple batteries set up to handle the load and not force the alternator to do the work. Also, they have the multiple batteries in the trunk with short 2 or 0 guage power wire for less resistance.

Also, consider running a seperate ground wire (4 guage) back to the battery in front from the stereo system...the reason for is is that most people ground to the chassis in the back, not realizing that there is resistance from piece of metal to piece of metal in the chassis...

Believe me that you should NOT need two alternators if you do the system right...