required alternator amperage
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=93061
Printed Date: April 29, 2024 at 3:45 AM
Topic: required alternator amperage
Posted By: johnny k-doe
Subject: required alternator amperage
Date Posted: April 17, 2007 at 5:46 PM
Hey! This is my first post on this forum. I have spent a lot of time perusing your forums, and the fact that your search function works especially well has helped me more than once; great website all around. Ah, I digress.
I have been looking into buying a new H/O alternator, and I would appreciate the recommendations as to the output I require. My maximum
amp draw from my two amplifiers is 180. I drive a 1995 Ford Explorer 4.0L SOHC. I have upgraded my Big 3 with 1/0 AWG wire. This is my daily driver.
My system-
(1) HK401SX (MA Audio) running at 1200 watts @ 1 ohm. Max @ 120 amps (i.e. three 40 amps fuses)
(1) P450.4 (Rockford Fosgate) both channels bridged @ 225 watts @ 4 ohms. Max @ 60 amps.
Is a 250 amp alternator in order?
Replies:
Posted By: jmelton86
Date Posted: April 17, 2007 at 5:54 PM
I think so. That's 70 amps left over. Since the Big3 is done I think 70 is enough to support your vehicles' electrical system.
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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: roo-dog
Date Posted: April 17, 2007 at 5:58 PM
i'd say o.k. but, the bigger, the better (in some cases). you can never have too big of an alternator, as far as i'm concerned. they are all regulated (most internally nowadays), so it's not like you will have too many amps.
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(4)g5-1244, (4)gtr12, (2)ppipcx2400, (1)pcx4125, (1)pc4800.2, (3) pair mb quart 6.5"Q, (4)optimas, alumapro (1)5 and(1)15 farad cap, premier deh-p860mp, pioneer xm -dual H.O. alternators
Posted By: johnny k-doe
Date Posted: April 17, 2007 at 6:12 PM
I think you guys are right. I found a 250A alternator from AlterStart for $300, I think I am going to do it.
Posted By: stevdart
Date Posted: April 17, 2007 at 7:25 PM
Please fill the forum in, via this thread, on how the upgrade goes. We don't get much commentary on alt upgrades. It's mostly like, "yes, you need to upgrade", but we don't hear the details from the other end about how the procedure went, the purchase, the installation, or the results. You're a good writer, so please consider it.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: johnny k-doe
Date Posted: April 17, 2007 at 9:50 PM
Thanks, I will try and do that. I still would like to call around to find a better price. I also want to call some shops and see if I might be able to get my stock alternator rebuilt to put out 250 amperes more cheaply than buying it new, but I have a sinking feeling on that one for some reason. Another question I was thinking of as I was calling all these different people, is what kind of quality difference I am going to run into. Do you suppose some alternators are over-rated like some (cheap) amps? Although, all the alternators I found are competitively priced, except a couple that were $100-200 over.
Posted By: jmelton86
Date Posted: April 17, 2007 at 10:17 PM
Does anyone know if there is a dual alt. bracket available for his 95 explorer 4.0? This would probably be best, right? ------------- 2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: stevdart
Date Posted: April 17, 2007 at 10:41 PM
I would say a question should be "will it make full output at 2000 RPM, and what will it make at idle?"
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: johnny k-doe
Date Posted: April 18, 2007 at 11:57 AM
| That is mostly what I am concerned with. The guy from AlterStart said that they make peak output at 1600 rpm, and that I would get 100 amps at idle. Then again, people say a lot of stuff. Do you know how to measure alternator output (in amps, of course)? |
Posted By: stevdart
Date Posted: April 18, 2007 at 12:21 PM
Nope. They'll show you the reading when they run the load test....whoever installs / tests it.
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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: roo-dog
Date Posted: April 18, 2007 at 6:18 PM
250 amps at 1600 rpm and 100 amps at idle is pretty good.
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(4)g5-1244, (4)gtr12, (2)ppipcx2400, (1)pcx4125, (1)pc4800.2, (3) pair mb quart 6.5"Q, (4)optimas, alumapro (1)5 and(1)15 farad cap, premier deh-p860mp, pioneer xm -dual H.O. alternators
Posted By: Aruman
Date Posted: April 18, 2007 at 7:59 PM
www.ohiogen.com
One of the best HO Alternators out there. ------------- Shaking The Neighborhood
Posted By: johnny k-doe
Date Posted: April 23, 2007 at 1:26 PM
I have decided what I am going to do. A friend of mine had an alternator rebuilt for his Road Runner at a local shop called Finch Alternator & Starter Rebuilders. High quality work. The guy has been doing this for over 30 years, and really seems to know what he is doing. He can rebuild my alternator to 250A for $350, installed. He has test equipment to hook up to the alternator, so I will be able to see actual output at various RPM. I really think that getting the work done at a local shop has several advantages to buying a new one off the internet or out-of-state. I did call Ohio Gen. They seemed to do quality work, but they were a little out of my price range. I am waiting for my tax refund before I get my alt. rebuilt, so it will be awhile before I get a chance to post how everything went. I'll take some pictures, too, since everyone likes pictures.  I have another question, though. Should I go ahead and buy a new battery when I get my newly rebuilt alternator, or can I just charge my current battery (about 2-3 years old) and get the same results? My battery is just a Super Start from, I think, O'Reilly.
Posted By: jmelton86
Date Posted: April 23, 2007 at 7:03 PM
Good looking around. Have your battery load tested while your there and base your decision on that. -I think you should while you still have your income tax money. ------------- 2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
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