Alternator Question Help please

[Cmccloud 10+ year member]

My car has a stock alternator on it(like 98 amps I believe), I was wondering if I go with a 140 amp alt if that would be a significant help? Would it be enough to run my kicker kx1200. I have 4 gauge now but am going to be going with a 0 gauge and getting a new battery too. Think it would be good or do I still need more? Thanks for the help guys

Click to read more...

 

[MECHMAN 10+ year member]

A 140 amp version will more than likely have LESS output at idle speeds than your stock unit. Unless it is based on a large case design, or you plan on revving your engine up when playing the system , I probably wouldn't reccomend it. I could tell you more if you put what kind of vehicle you have.

 

[audioholic 5,000+ posts]

Why is idle speed charge capabilities so important? Yes obviously we'd all love our alts to put out max power even at idle, but how often do most of us sit for loong periods of time with the car idling? Much much less time than we do running the engine at normal operating RPM's. So unless you are a competitor who will be getting scored with the engine running at idle, I dont see the huge problem.

This is the perfect example. Id rather have an alt that only puts out 50amps at idle, but will do 140 amps when the engine is running operating RPM's than I would an alternator that puts out 70 amps at idle, but only 100 amps with the engine RPM's higher. Why? Because the vast majority of the time my engine will not be sitting at idle.

 

[snoopdan 5,000+ posts]

...and to add to audioholics answer on competitor situations - they should already have a large battery setup anyways so that 200 or more amps isnt going to make much of a difference anyways and the alt is really just a battery charger after the run thru the lanes.

to the original poster, id look more into getting a battery or two - whatever you can fit thats convenient. Even a POS walmart battery with 900 cca would benefit you more than an alternator upgrade.