350 MAG high output alternator

69fastback

Does anyone other than Mechman make a high output alternator (170 amps or higher) for the 350 Mag, that is a direct bolt on? I have a KXMA 1200.1 and KXMA 800.8 that were sharing a 4 gauge power supply before, and have now been properly rewired using 4 gauge for each amp, and the sub configuration was changed from one drawing 600 RMS, to now 2 drawing 600 each. This has obviously greatly exceeded the capacity of the charging system, and is causing the sub amp to hit the low voltage cutoff with anything over about 3/4 volume.  Currently it has 2 850 CCA deep cycle batteries, and I'm about to put the largest blue tops in it, but using OHMs law (POWER = VOLTAGE x CURRENT), I really need a 200ish amp alternator to provide the proper power to the amps, and power the rest of the boat. 170 would really probably be okay, as that comes out to 2380 to power the whole boat, and that's just using 14 volts, but it's better to have a little extra since you won't typically see a full 14.4 (or sometimes even 14) volts at the battery. What options are out there for a higher output alternator?

Handymans342

Be careful of that upgrade as all the wiring, isolator and such are not rated for that output

69fastback

Amps are “on demand.”  Changing the amperage output capabilities of the alternator won’t affect the wiring. If the system only demands 70 amps, then the alternator produces 70 amps. Any item in the boat that has factory wiring will still have the same amperage traveling through it’s wiring, because that’s all that specific item draws. 

LaRea

Does your alternator output go to a battery isolator?  If so, Handy is right - gotta make sure the isolator can handle it.  

I thought for sure that Hardin Marine would have one, but their biggest is 120 amps.  Take a look at Power Bastards.  

69fastback

Well two different shops assured me they run systems with 3 times as much power as mine through the same switch I’m using and it works great. 

I found a local shop that will rebuild mine to get the output I need. 

Handymans342

Your going to cause a fire

LaRea

The battery isolator - IF you even have one - is different from the battery switch.  Not all boats have isolators, so maybe you're fine.  But if you have one, it's probably rated for less than 100 amps.  

Do you have an onboard battery charger that runs on shore power?  If yes, you probably have an isolator too.  The alternator and charger will be connected to the isolator, and the isolator will connect to the batteries.

69fastback

Handymans342 said:

Your going to cause a fire

You are incorrect. A good friend of mine is the lead installer for Kicker. He’s built every one of their demo vehicles from the ground up. If you feel you are more educated in this field than him, feel free to call their tech line and ask for David and discuss it.  Otherwise, please tell me how increasing the available amperage to an amplifier will cause a problem. Amps are on demand. Not a single other component in the system will receive more then the demand requires. 

69fastback

LaRea said:

The battery isolator - IF you even have one - is different from the battery switch.  Not all boats have isolators, so maybe you're fine.  But if you have one, it's probably rated for less than 100 amps.  

Do you have an onboard battery charger that runs on shore power?  If yes, you probably have an isolator too.  The alternator and charger will be connected to the isolator, and the isolator will connect to the batteries.

232 bow rider......no

Handymans342

69fastback said:

Handymans342 said:

Your going to cause a fire

You are incorrect. A good friend of mine is the lead installer for Kicker. He’s built every one of their demo vehicles from the ground up. If you feel you are more educated in this field than him, feel free to call their tech line and ask for David and discuss it.  Otherwise, please tell me how increasing the available amperage to an amplifier will cause a problem. Amps are on demand. Not a single other component in the system will receive more then the demand requires. 

I could be wrong however in order to deliver the amps don't you need the wire size as the highway?

69fastback

Handymans342 said:

69fastback said:

Handymans342 said:

Your going to cause a fire

You are incorrect. A good friend of mine is the lead installer for Kicker. He’s built every one of their demo vehicles from the ground up. If you feel you are more educated in this field than him, feel free to call their tech line and ask for David and discuss it.  Otherwise, please tell me how increasing the available amperage to an amplifier will cause a problem. Amps are on demand. Not a single other component in the system will receive more then the demand requires. 

I could be wrong however in order to deliver the amps don't you need the wire size as the highway?

There is 4 gauge wire running to each amp. The other components don’t matter because they will not draw more amps than normal, therefore they will not be fed more amps than normal. 

69fastback

Alswagg said:

Go ahead. But why are you wanting a 170 amp alternator?   If you don’t change or upgrade your wiring and breakers/fuses, you won’t ever use that much amps.   Your system is set to handle 70 amps continually. 

Why would I need to upgrade the factory components that will not draw more amps than normal?  The amps have their own dedicated 4 gauge wire. Power takes the path of least resistance. When the amps require the added amps, their upgraded wires will deliver it. 

Handymans342

Where does the amp wires go to directly??

69fastback

A higher output alternator will have zero effect on any factory components, or the factory wiring. There will be no added amperage running through any of that. The alternator is rated at MAX amps and does not produce that all the time. It produces what is required of it, based on draw. If the total system is drawing 100 amps, all components do not get 100 amps. Each item is getting what it needs based on its draw. My radio amps draw a lot. If it’s actually getting 14.4 volts, they require 139 amps at full draw (based on music volume). This isn’t redneck theory. It’s based on OHMs law. It’s math that’s a proven law. The increased capability of the alternator doesn’t affect anything other than providing sufficient power for everything, based on the added draw of the radio amplifiers, and that increased amperage goes to the amplifiers. 

69fastback

Alswagg said:

Ok you are adding stereo amplifiers.   And each ampliphier is powered up to say 160 amps or so.  This amperage is coming from a storage of amperage from the battery bank.  The alternator is simply replenishing that amperage.   If the draw from the battery is so as the higher output alternator is over 70 amps the charge circuit fuse will blow.  This is why I ask, why are you boosting the alternator amperage?  I understand you want to replenish fast, but without upgrading the charge circuit wiring you will create problems for yourself.   Good luck 

I’m already drawing more than that from the batteries, regardless of alternator output. With that theory, it should have already blown the fuse. 


The fact of the matter is, I’m not reinventing anything here. This is being done in boats across the country. It works, and it’s not a fire hazard, 

Handymans342

Do they put out 170 amps at idle or 2000 rpm? So you will have to run the motor all the time you are parked playing tunes??

69fastback

Handymans342 said:

Do they put out 170 amps at idle or 2000 rpm? So you will have to run the motor all the time you are parked playing tunes??

It’ll make it at idle. And no. The XS batteries will do fine for quite some time while parked. It’s not like we listen to it turned up all the time. When parked, I run where just we can hear it, so to not disturb others, but even with that, you still need a proper output from the alternator to keep everything happy.  


These batteries make it happen. 
https://4xspower.com/shop/xp-series/xp-series-batteries/xp3000/

69fastback

Alswagg said:

The cool thing is, when the charge fuse blows, it will also eliminate all 12v power to the ecm or if you are carbureted, the ignition system.  This way you will be left out in the water unable to start and run.    This is unless of coarse someone bypass the 70 amp fuse. 

Yep that’ll be cool. Want to put a wager on if that happens or not?  A friendly bet amongst forum members?  Why not make it a pool?  Let’s do a $50 buy in. 

69fastback

Oh and even better! It is indeed a MPI so I’ll be toast!   Good thing I’m a strong swimmer. My wife and kids are screwed though. 

Cableguy Greg

Why not use capacitors that are rated to give you the voltage that you need at the spikes? All they are is a storage device. It has been a while since I built a system in a car, or boat, but caps are what I always used to prevent a huge voltage drop at high levels.

69fastback

Cableguy Greg said:

Why not use capacitors that are rated to give you the voltage that you need at the spikes? All they are is a storage device. It has been a while since I built a system in a car, or boat, but caps are what I always used to prevent a huge voltage drop at high levels.

The experts that I know that do it for a living, say that my power needed vs the power supplied need more than caps to be correct. Caps would make it better, but to do it right I need more alternator output and better batteries. 

GMSLITHO

Wow that must be some powerful sound system ,live anchored near a few boats with those .........I usually end up moving 

dalek

Am I missing something here? Surely 170 Amps at idle would take about 5% of the total output of the engine?

skennelly

I remember back when I was 20 I wanted the loudest car around...and came close to that.  Now just roll my eyes when I see a car with music so loud it's not comfortable.

69fastback

GMSLITHO said:

Wow that must be some powerful sound system ,live anchored near a few boats with those .........I usually end up moving 

As I said, when around others, I don’t turn it up. When we were out this weekend there were 2 old men in a pontoon boat that we were beached next to, and they started out listeneing to George jones, and ended up with Eminem. Their set of for 6.5”s could be heard over mine. Just because someone installs this stuff doesn’t mean they don’t have respect for others 

69fastback

skennelly said:

I remember back when I was 20 I wanted the loudest car around...and came close to that.  Now just roll my eyes when I see a car with music so loud it's not comfortable.

I don’t know what it’s like where you’re at, but in north Texas we have 80% tow boats. You ever heard the stuff they put in those?  I’m far from the loudest, and that’s not what I’m trying to accomplish. Once again the people on this forum prove to be judgemental, make poor assumptions, and look down on others. This isn’t the first time that I’ve brought this up and really it’s quite ridiculous. I started a thread asking a direct question and after a full page of replies, there hasn’t been a single attempt to answer it. Instead, I get condescending remarks from judgenental people. I even get comments alluding that I’m acting like a 20 year old, when in fact it’s the people with the condescending judgemental attitude that are acting that way. Al is just trying to be helpful with his comments, but the others, not so much. 

Handymans342

Whoa cowboy @69fastback. Don't you know that you can't inject tone in a conversation or an email etc?? I thought I had some valid questions and everyone has a right to express them selves uhhhhh its called the first amendment just like the way you blasted everyone geeezzz .

69fastback

Handymans342 said:

Whoa cowboy @69fastback. Don't you know that you can't inject tone in a conversation or an email etc?? I thought I had some valid questions and everyone has a right to express them selves uhhhhh its called the first amendment just like the way you blasted everyone geeezzz .

You did, and it wasn’t directed at you. And I missed one of your questions. The wire from the amps goes directly from the amps to the perko switch, to the batteries. The guys I know that do this stuff say they run huge power through those Perkos all the time without issue. I was just going to wire them directly to the batteries because I was concerned the perko would be a bottleneck in the system, but they said no. 


Everything in the boat that needs to be addressed has been addressed. All I asked was if anyone made a high output alternator, other than Mechman, that’s a direct fit replacement. As I pointed out, literally not one reply has been to answer the only question I asked. I appreciate the help from al, Larae, and you. The worthless childish remarks from others, I think everyone can do without, and I’m sure you can understand the frustration it causes when I have to sit here and explain myself repeatedly with no answer to the very specific question I asked.   

Handymans342

69fastback said:

Handymans342 said:

Whoa cowboy @69fastback. Don't you know that you can't inject tone in a conversation or an email etc?? I thought I had some valid questions and everyone has a right to express them selves uhhhhh its called the first amendment just like the way you blasted everyone geeezzz .

You did, and it wasn’t directed at you. And I missed one of your questions. The wire from the amps goes directly from the amps to the perko switch, to the batteries. The guys I know that do this stuff say they run huge power through those Perkos all the time without issue. I was just going to wire them directly to the batteries because I was concerned the perko would be a bottleneck in the system, but they said no. 


Everything in the boat that needs to be addressed has been addressed. All I asked was if anyone made a high output alternator, other than Mechman, that’s a direct fit replacement. As I pointed out, literally not one reply has been to answer the only question I asked. I appreciate the help from al, Larae, and you. The worthless childish remarks from others, I think everyone can do without, and I’m sure you can understand the frustration it causes when I have to sit here and explain myself repeatedly with no answer to the very specific question I asked.   

Most people don't even know the answer or solutions. Most people shouldn't even own a boat for that matter LOL

raybo3

@fastback it appears to me that other members were trying to answer your questions. Alswagg once worked at Rinker building these boats and knows them inside out. A couple of members made a comment about loud music and you go off on the entire forum. Not fair to the members trying to help you. It seems you asked a question but then had an answer for everything. We try to play nice here and to help one another. You ask a question you get an answer. You may not like the answer but you get one. You state "there hasn’t been a single attempt to answer it". WRONG!!! If you don't like peoples opinions don't ask.......... Let's just all get along................. Just say'n 

Cableguy Greg

I guess my comment about caps was childish and uncalled for. Oh well. Good luck with the build.