Will a 115 amp alt be enough for my setup???

[MrJollie 10+ year member]

I have a pioneer gm-x972 amp(800 watts max/400 watts rms/150watts rmsx150@4 ohms) and a Jensen A600 HLX amp(600 watts max/50 watts per channel@the front/100 watts per channel @ the rear@4 ohms) i use the pioneer for my sub, and might want to add another. The Jensen runs my four speakers. I will try to elaborate on the situation as much as possible....so here's the rest:

the pioneer amp has two 30 amp fuses, where the Jensen has two even bigger 35 amp fuses. The biggest add on alternator that i found for my stock(60 amp) alternator is a 115 amp alternator from 4x4parts.com.

I have not found a shop in my area(Northeast PA, near Scranton) that deals with rewinding alternators. so if anyone knows of a place or a number within 75 miles that rewinds alternators, let me know. such a place could be NorthEast PA, NorthWest NJ, or SouthEast NY area if possible. i also have a cap for later on when i get the bigger alternator. i've seen people with 80-90 amp alternators that run bigger systems than mine and don't have dimming at all. so should i go with the 115 Amp alternator (pricey @ $325) or does anyone know of a place to have it rewound.

thanks for any responses and sorry about the long message, i can't seem to find anyone who can help me out and thought that this would be a good place to try. //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

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[dr. no 10+ year member]

Are you having problems w/ dimming or not? Is your system even installed yet? Call some local mechanic shops and see if they know someone who will rewind your alt. Prob be cheaper than a new one.

 

[alton001 10+ year member]

Man for that price you can get an alternator well over 200 amps. Contact any of your local parts store, and they can suggest a suitable aftermarket replacement that's only a one wire hookup. It will save you bundles in both the wallet and the installation process.

 

[MrJollie 10+ year member]

i checked with most of them around ME, and they(parts places) don't have any aftermarket alternators for my vehicle. yes, i did have everything installed, just with the one sub in though. i didn't get the other yet. the lights do dim noticably. i may just have to call the local mechanic shops. i don't think the parts stores have been able to help me out much. but my main question was: will a 115 amp alternator be enough to handle my application?(including after when i have the second sub installed) thanks

 

[n2audio 5,000+ posts]

No one will be able to give you a definite answer on this one. Some people have problems with 500 watts on a 90A alternator, and some people run 1000 watts with a 70A alt with no problems at all. However, personally, I think 115A would be fine for the application you're talking about.

As for the second sub -- will you be changing the load on the amp? How do you have the single sub wired? How will you wire them when you add the second? Regardless - chances are the output of the amp won't change all that much. Based on the ratings you gave the pioneer is 150x2 @ 4 ohms and 200x2 at 2. So even if you're going from stereo to bridged I don't think the power change is really worth considering.

Basically I think 115A would be fine.

 

[venom107 10+ year member]

Well I have two amps and used to have two Type R's (getting another back soon). Anyways my old Profile800sx did dim a little with two Type R's but not much it had 3 20A fuses and my alpine 4 channel had 1 25A fuse. I upgraded my amp to a class D USX800D and it only has one 30A fuse and now it doesnt dim at all with two subs no matter how high the volume. Lucky for me my stock Toyota Tercel came with a 100A alternator. MUCH MORE Than most other cars especially for the size. Just get a more efficient class D amp that will help if you dont wanna change your alternator.

 

[burtonsnow83 10+ year member]

how exactly do the fuse ratings relate to how much strain they place on the alt?

 

[venom107 10+ year member]

The fuse ratings show how much power will be pulled from an amp. That's why on my USX800D that amp is not going to pull over 30A from my alternator and if it does the amp fuse blows so thats how they directly relate. Just make sure that the fuse ratings together to not exceed the fuse rating on the alternator and you shouldnt have a problem.

 

[n2audio 5,000+ posts]

Originally posted by venom107 The fuse ratings show how much power will be pulled from an amp. That's why on my USX800D that amp is not going to pull over 30A from my alternator and if it does the amp fuse blows so thats how they directly relate. Just make sure that the fuse ratings together to not exceed the fuse rating on the alternator and you shouldnt have a problem.

Actually it's not quite that simple. A 30 amp fuse will pass 40A for several seconds, and generally will pass 60A for a second or so before it blows.

And by no means is it a rule to keep your amp's current draw less than that of your alternator. Many stock electrical systems are capable of powering audio systems approaching 2000 watts rms.

Test tones may be a problem, but typical music will rarely if ever require 100% current capabilities of your amps.