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Anonymous | I have a 1991 honda civic with a 2400 watt amp powering 2/12 inch cerwins. Do I need to get an upgrade on my alternator, and if so how big should I go. And I am also concerned about needing a different voltage regulator to handle the bigger alternator. |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 1471 Registered: Dec-03 | some alternators use an internal voltage regularot. in any event, if your lights dim, or voltage drops below 12V at idle, and 13.5V above idle, then you need a larger laternator. that's the way to tell. 2400 watts is going to be around 220+A of current draw just for the amp at peak output. |
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Anonymous | how can I tell if it drops below 12v at idle and 13.5 above idle? |
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New member Username: Tim_9872Post Number: 9 Registered: Mar-04 | Like Glasswolf just posted "if you lights dim". I think this is true to a point. If you have a older car the ground connections might be poor or something like that. If it only dims on the harder bass hits you should be fine. I've seen 200w rms cause lights to dim on a car with a 60A alternator. Thats like 17A of draw. This is one cause were a cap MIGHT help. |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 1495 Registered: Dec-03 | you can use a digital multimeter. or a VOM. either can be had from radio shack for about $10-20 you just connect to any ground and +12V spot in the car and watch the voltage reading. |
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Bronze Member Username: Tim_9872Post Number: 16 Registered: Mar-04 | I use this tool that measures the voltage and the amps coming out of the battery. I've noticed that the voltage will drop after 20 amps of load on a brand new battery. Do you think its a good idea to invest in a car audio specific battery even if you're only pulling 30 amps out of a battery? |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 1506 Registered: Dec-03 | when the car is running, you'll want a bigger alternator. the battery isn't the problem. |
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Bronze Member Username: Tim_9872Post Number: 29 Registered: Mar-04 | When the car isn't running I'm talking about. I'm also talking about a tool the makes a load on a battery. |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 1519 Registered: Dec-03 | measuring voltage is done with a voltmeter. amperage is measured with a clamp type or in-line ammeter. if you want long term high current system use without the car running, look at a bank of deep cycle batteries, a battery isolator, and a high output alternator capable of both running your audio system, and recharging all of the batteries you plan to use. |
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Anonymous | do I watch for the lights to dim at idle or at a running rpm. because I am pretty sure that I could make the car kill at Idle, if I turn it up loud enough. |
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Anonymous | and I thought you (glasswolf) said that a cap is a worthless investment. |
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Silver Member Username: TboneOK United States Post Number: 111 Registered: Feb-04 | If you can kill the car at idle by turning it up load, you definitely need a rewound/high-output alternator. |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 1547 Registered: Dec-03 | I did, and they are. capacitors won't make up for a lack of current from the alternator. |
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Anonymous | Do you recomend rewinding the stock alternator or going with an aftermarket brand. and I know I asked this before but where do I find out where the voltage regulator is. because if it is on the alternator, whoever rewinds the alternator should put a regulator to handle the increase. but then if I have an external regulator will I need to upgrade. |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 1553 Registered: Dec-03 | either way, new or rewound. whichever is cheaper and puts out the power you need. as for internal or external regulator, a Haynes manual will answer that, and the place that puts in or builds the alternator will help with the regulator too. its sort of a package deal same with the harnesses for them |
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Anonymous | thanks for the help glasswolf |
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Bronze Member Username: The_masterBellmawr, Nj Usa Post Number: 15 Registered: Mar-04 | heres the deal stock 91 honda alt if 55 amps- you need and high out alt--also external regulator-do not go internal thus will not work long due to heat from alt-when ever upgrade al always go external reg-- now the next problem with this honda--a hondas alt spins reverse from most alt-the fan they use for the alts are stamped steal-and the problem is when you drop the clutch or put a good load on alt it put more pressure on the fan blade to the alt, causing it to bend in half and throw the belt of the alt--you will be replacing the belt often--here is a good cheap fix-have a welder spot weld the fan at all spots he can without using to much material where it out of balance--i had this issue with my civic 91 and this was only cure-good luck--you need the alt, a cap is beyond what you need-although when the alt is in a cap will help you--also you may have to play with different pully combinations on the alt--you need it to produce enough amps at a low rpm-so a bigger pulley on alternator will be good-also when you find the right belt that fits write it downs and dont loose this info-cause you will not be able to use factory belt-must go bigger-good luck hope this ends your nightmare-might creat another!!! |
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Anonymous | how would the fact that the alternator spins backwards make any sort of a difference in the durability of the pully. I have never had a problem with bending any thing on the alternator. frankly I think that is almost impossible. I have had 2 hondas and drove both over 200 thousand, with no alt problems. so if what you are saying is that just because they spin backwards it is prone to breakage. that does not matter because it is designed to spin that way but thanks anyways. |
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Bronze Member Username: The_masterBellmawr, Nj Usa Post Number: 18 Registered: Mar-04 | hey anonymous-were here to help not start a pro-if you know everthing dont ask questions--you should know the answer--if not gire a pro and get out of your moms shed, before you burn it down!!!!when they stamp the fans out of steal they sre stamped in the oposite way the honda work-thus they are weaker when spinning backwards--if you upgrade the performance and drop out the clutch it WILL BEND--GURANTED----besides its not the pulley that bends its the fan |
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Anonymous | and if that was the case, if you drop the clutch or spin the tires or rev your engine up really fast or what ever than any alternator would bend if that is what your theory is. if glasswolf has any comments whitch I have a feeling he does I would like his opinion. |
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Bronze Member Username: The_masterBellmawr, Nj Usa Post Number: 19 Registered: Mar-04 | i didnt register on this site to get info-i reg to help others out with my experience in the field for 14 yrs-if you dont like what i recomend thats ok, but keep it to yourself-some people are that rude. you are getting free info and still debating it(get a life) the alternator problem with the fan is not just a guess at this-this occured on my car with an esoteric alternator-it happened 5 times before the tech and myself at eso were able to come up with a fix-this was 7 years ago-maybe this issue is resolved-maybe not-it was thrown out to you people as apoint of info to pay attention too--if you dont like my post dont read them-dont go by anonymous and let us try to figure out who you are-put your mane in so we all know who the a$$ is---im sure veryone will agree-if you want to arguee about thing do it somewhere else on aol or something!!!!!!!!!!!! |
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Bronze Member Username: MaxkillaMalta Post Number: 31 Registered: Jan-04 | So John what must i tell my mechanic to do to arrange this problem ?? I'm gonna have 2 alternators the stock one for my car and the other one for my car audio... would i have any problems with this system ?? and What must i tell my mechanic to do to repair this problem ?? |
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Bronze Member Username: The_masterBellmawr, Nj Usa Post Number: 20 Registered: Mar-04 | 2 alternators--? No way do you need this--look the fan prob I mentioned may not happen-it maybe fixed by the aftermarket alternator companys by now--when I did this it was the biggining of replacing alternators-- let put it this way I paid 1200.00 for an alt--back to you-just get a high alput alt-if you add up the fuses to your amps-the ones on the amps-divide by 2-then with the Honda add 50 this will give you a good idea of how many amps you need--you may want to ask the alt company you buy drom-what the ampereage is at 600rpm-(or double check what idle rpm your car has-at idle--you need to maintain amperage at idle for the system or this is a waiste for you--if you car idles at 500 rpm then you need the alt to work at 500-if the alt will not give the amperage you need unless it hits 700rpm-then you will put a bigger pulley on the alternator thus spinning it faster eveb though the car is at same rpm--you may have to do a trial error on this--I know on this car the alt is not easy to do-the drivers tire and a frame and axle must be pulled out of trans-so I suggest buying the bigger pulley and going to shop with meter when the guy puts alt in-once in and still apart -start the car and try to see if it is enough-if still dimming and other isssues then pull out and put on larger pulley-this way the mech wont charge you 2 times for the job--probally cost @200.00 for alt install-unless you get a good deal-well good luck any more quest let me know--but only 1 alt-never will you need 2 nor can you get 2 in this car--you can email me direct at monzie32@comcast.net |
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Anonymous | settle down john you make all sorts of acusitions about me and you have no idea who I am. and you are a 14 year veteran you cant take a little feedback about your info. maybe it is your ego but I think that you are over reacting about what I wrote to you, sorry if I hert your feelings but dont let a little anonymous feedback get your pannties in a bundle. |