when do u have to change the altanator when upgrading to a high end system. how can you tell??? i have a system but i want to upgrade but how do i know if i have to upgrade?

 

anyone????

 

Alternator is the last item to upgrade. It's the most expensive and least likely to be needed. It also adds the most unwaned noise to a system.

If you have done everything else connect jumper cables to your car and one with a "high output" alt. Start up your car, system, etc. If there is an improvement then you may want to upgrade your alt. But if you have other issues such as a bad battery or poor wiring the larger alt may just mask those items temporarily.

A properly wired 4th or 5th generation maxima can power a 2000 or more watts RMS stereo MUSIC without issue. If you start using non musical material such as tone bursts expect your power needs to increase.

 

while you are correct about the 2000 watt rms pwer handling, this might not be so true in the long run. if u push an alternator to 120% of its limits for an extended period of time, you will slowly destroy the diodes in the alternator. this is a very bad thing. results in less power, more DC ripple, very bad for the charging system. if you plan a system that is 1500 watts or more, invest in a quality high output alternator. if installed properly it shouldnt induce unwanted noise. and CAPs wont really help all that much in a very high power system, its just a waste of money. you would need a 50 farad cap to be able to handle that kind of power with ease and maintain a constant voltage. yea the rule of thumb is 1 farad for every 1000 watts, but with most musical content, the cap doesnt have the time it needs to fully recharge again because its being drained again by another burst before it pulls current from the battery or alt. caps need only miliseconds to charge, but with a musical signal, its not enough time.

 

Actually that is more than enough time for a cap to recharge. Typical music has been proven time and time again to use a small percentage of an amps rated power, Less than 20% when averaged out. So to use 120 % of the alts capaticy for 20% or the time, you are using 24% of it's capacity on average. That is what matters with alts and music.

Go read up on high output alts. They are the dead last thing you want for a daily driver non SPL vehicle. Noise is just one of the issues. The other issue is battery charging difficulties at normal engine speeds. There is a trade off with everything. To get more max current from an alternator the rpm range where the power is delivered is much narrower than a stock alternator. At idle they may have less than half the current of the stock alt. If these were honda civics or some other 4 cylinder a new alt may be needed. But the stock maxima alt has 110 - 120 amps, hardly a slouch.

 

read the voltage at ur cap next time ur blasting ur music, see if it stays at 13.8 volts for a long time. this is the rule of thumb for caps: if the voltage drops across a cap, its not holding enough charge. the voltage across a cap that is sufficient for a system should never drop.

 

Proper wireing is key!

 

yea, that was mentioned in another thread

first thing to do is replace factory ground cable at the battery since it's usually 8awg. then try to replace wiring from alternator to battery and its ground. that usually improves things a lot.