# More Powerful Alternator The Solution?



## SXY_SR20DET (Aug 21, 2003)

Installed my system about 3 weeks ago now, and everything works fine, save the rattle that my trunk has and the fact that my lights are dimming even with a .5 ferad cap (and yes I know I should be running around 1 ferad, when I can I will get another cap).

I guess what I would like to know is if it's a good idea to replace my battery with perhaps a sprial cell 770 CCA battery from my work at Canadian Tire. Either or that or perhaps get a bigger alternator for my car. I'm kind of at a loss as to what to do here. I was told that even working on my grounds would be good, but I was told that my grounds are pretty well done for my car. Anyone have any idea what to do?

The second thing is that my trunk rattles (from what I can see where the lid rests on the bottom part of the chassis) and I would like to stop it completely. Do I need to "Dynomat" it, or is there an easier solution to the problem that won't cost extreme amounts of dollars and that won't look absolutely "ghetto" as everyone is putting it these days?

Any help would be appreciated in this time of frustration.


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## wickedsr20 (Aug 8, 2002)

SXY_SR20DET said:


> I guess what I would like to know is if it's a good idea to replace my battery or perhaps get a bigger alternator for my car. I'm kind of at a loss as to what to do here. I was told that even working on my grounds would be good, but I was told that my grounds are pretty well done for my car. Anyone have any idea what to do?


Upgrading the grounds won't make as big of a difference in our cars as upgrading to a larger alternator would. Replacing the battery would be a good idea. The 1 farad cap will help a little over your .5 farad, but not to the degree I think you're looking for. You may want to look into getting a higher amp replacement if you're really looking to pound it out.



SXY_SR20DET said:


> The second thing is that my trunk rattles (from what I can see where the lid rests on the bottom part of the chassis) and I would like to stop it completely. Do I need to "Dynomat" it, or is there an easier solution to the problem that won't cost extreme amounts of dollars and that won't look absolutely "ghetto" as everyone is putting it these days?


Dynamat (or similar damping material) will work well in curing your trunk lid rattles. You also may want to secure your tag plate better (I'm using 4 screws to hold it - NO noise from the tag now) as this can also be a major source of rattles. For a slightly cheaper solution, you could try shooting a little expanding foam in between the actual lid and the frame it rests on. Just be REAL careful not to shoot too much up in there if you choose this method, since it will expand and may cause creasing and buckling of the body panels if done too excessively.


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## 200sx98fl (Jan 5, 2004)

SXY_SR20DET said:


> Installed my system about 3 weeks ago now, and everything works fine, save the rattle that my trunk has and the fact that my lights are dimming even with a .5 ferad cap (and yes I know I should be running around 1 ferad, when I can I will get another cap).
> 
> I guess what I would like to know is if it's a good idea to replace my battery with perhaps a sprial cell 770 CCA battery from my work at Canadian Tire. Either or that or perhaps get a bigger alternator for my car. I'm kind of at a loss as to what to do here. I was told that even working on my grounds would be good, but I was told that my grounds are pretty well done for my car. Anyone have any idea what to do?
> 
> ...


First off how bad do they dim with the .5 farad...i was having the same problem for a while but i finally fixed it. I tend to stick to these rules: Dont buy the cheap stuff if you want quality sound...some stuff you can get away with. You wanna stay with min. of 4 gauge wire for your battery same with your ground. For the type of Power cap you anything 400w or less .5 500 to 1000 w 1.0...but to me thats not the case as i have a hifonics atlas VI 400watts mono amp with a 1.o rockford cap and my lights were still dimming need less to say i went wit a Bat cap for the money it was a good buy. You could also go with a better altenator but then your gonna have to get bigger wire for your alt. Always dynomat your trunk...thats the first thing you know when someone took pride...how clear the bass hits. If you feel like going the extra do the whole car if needed. Maybe some of this info helped you out.


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## tosainu1 (Aug 15, 2002)

200sx98fl said:


> First off how bad do they dim with the .5 farad...i was having the same problem for a while but i finally fixed it. I tend to stick to these rules: Dont buy the cheap stuff if you want quality sound...some stuff you can get away with. You wanna stay with min. of 4 gauge wire for your battery same with your ground. For the type of Power cap you anything 400w or less .5 500 to 1000 w 1.0...but to me thats not the case as i have a hifonics atlas VI 400watts mono amp with a 1.o rockford cap and my lights were still dimming need less to say i went wit a Bat cap for the money it was a good buy. You could also go with a better altenator but then your gonna have to get bigger wire for your alt. Always dynomat your trunk...thats the first thing you know when someone took pride...how clear the bass hits. If you feel like going the extra do the whole car if needed. Maybe some of this info helped you out.



If you get a new high output alternator, make sure you get a warranty because those things are very expensive, tempermental and affect the rest of the engine. If you completely dynamatted the car there would be no need to go with two 12's, and would sound alot cleaner at all speeds.. After blowing THREE factory alternators i decided a big system is not all its cracked up to be in these small cars, less is more in this case.


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## UofLsentra (May 25, 2003)

A new alternator would probably cause you some other problems that overshadow its benefits, and its not too cheap. I had to pay $330 yesterday to replace mine. I was on a roadtrip back from Tallahassee, Fl to KY when my alternator died on me. So I was stuck in Jasper, TN and got towed to a Nissan dealer and had to pay up or stay in TN. I'm just pissed it didn't happen here at home, I could have saved a lot of $ since I use a Nissan mechanic who work at the dealer for 20 years and started his own shop. 

Anyway... no more threadjacking. The 4 screws on the license plate can make a world of difference. It did on my brother's Civic. What I did for the rattle in my car was port the carpeted board(board that lays behind the rear seat 'headrests' and tucked under rear window). I cut one small quarter-size hole on top of each speaker back there and then used some stuff that looked nice to clean the cut edge up. It was enough to fix my pain in the ass rattle that I get with just some aftermarket Infinity Reference speakers and it kept the fact that I have aftermarket back there hidden(security). You can put 2 big port holes(maybe baseball-size) back there, too if you want to try it. That what a friend of mine with an Intrepid and 2 15's did along with some dynomatting to fix his huge rattles.


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## tosainu1 (Aug 15, 2002)

QX100.2 Specifications:
Power output: 
35 watts RMS x 2 (4 ohm load, 1% THD) 
50 watts RMS x 2 (2 ohm load, 1% THD) 
100 watts RMS x 1 (bridged into 4 ohms, 1 % THD) 

These are the specs for your amp as far as i can tell...I don't know how hard you are running your amp or what ohm load your speakers have, but this amp seems pretty pathetic to run two 12's. Bridged at a 4ohm load, you are only getting 50 watts per speaker, pretty low....Then again it is a class D amp, which is supposed to be pretty efficient, but i think your amp is pulling alot of amps and is probably being run at 1ohm, and that is what is dimming your lights. A larger cap would be a good idea, larger cables(2 or 0 ga.) would be a better idea before you go changing alternators out. Getting a larger battery is gonna do zilch except start the car exactly the same as the old one is doing right now. What else do you have in your system? what is powering the mids and highs? A nissan sentra has a tin can interior and is very loud at speed. To get all the rattles out, your talking major dollars, plus getting a large alternator from Stinger is gonna run like 500 or more. Getting quality cabling of a good size for spl systems(which is what you seem to be going for) is gonna be lots of dough also....What i'm saying is doing it right is not really worth it in my book, but then again i have 8 years of experience and alot of money(at least 5-7k) in it and was still not satisfied, so dont take my bitter ramblings as gospel.....


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## SXY_SR20DET (Aug 21, 2003)

I talked to a buddy of mine, and he's running 3 concept 15" subs and a Rockford 2000 watt RMS amp (around there anyway), only one ferad cap with 4 deep cycle batteries, so mad reserve capacity. He said that what he did was completely revamp his grounds, except for his headlight wiring harness. He's got a Mazda B2200 with a Chevy 4.3l vortec engine, nitrous, racing cams, the whole shot. He did the swap, etc etc., so I know he knows what he's doing.

I did get that spiral cell after frying my alternator when my music was very low and I was at idle. Luckily, I managed to get the same alternator from a friend who is doing an SR20DET swap in his 200sx SE for 50 bucks Canadian!! Talk about helping a buddy out... Thanks Kelly! But yea, I'm seriously looking into getting a better alternator. Has anyone gotten a Chev or Ford one and modified it to fit their 200? If so, I wouldn't mind talking to you! I did relocate my grounds, and most of the rattle came from the end of the trunk resting near my bumper. I just extended the rubber stubs on my trunk lid. So, new spiral cell battery, factory nissan 60A alternator (small assed POS, but works for the meantime), relocated 4 guage ground & wire from my amp, and less rattled trunk. The lights dim a bit, but nowhere near the amount as before.

I figure that getting a cap will only let me have more "reserve".. it won't solve the problem. A new alternator seems to be the best advice here. So if anyone can help me with giving tips for fabricating a Chev/Ford alternator for my car, please let me know! Thanks for all the feedback guys.. 

Just so people know the proper specs for my amp:

Power output: 475 watts RMS x 1 (4 ohm load, 1% THD), 900 watts RMS x 1 (2 ohm load, 1% THD) 
Frequency response: 20-330 Hz (± 1dB) 
Signal to noise ratio: > 90 dB 
Input sensitivity: 200mV-4V 
Minimum load stability: 2 ohms 
Dimensions: 17.75" L x 9.5" W x 2.1" H

Specs for the Thunder 6000 subwoofers:

Size: 12 inch 
Sensitivity: 87.2 dB 
Frequency Response: 29-150 Hz 
Recommended RMS Power: 250W 
Peak Power Handling: 500W 
Impedance: 4 ohms subwoofer wiring options


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## Punkrocka436 (Jul 8, 2003)

CAPACITORS DONT DO SHIT....I REPEAT...CAPACITORS DONT DO SHIT. 

Do not buy into the hype about capacitors, unless you are talking about 40 farads. Before you look at going into a new alternator...try upgrading the big three first

The big three would be:

1. Upgrading the Wire from the negative battery terminal to the ground location with 4-1/0 Gauge wire.
2. Engine block to grounding point wiht 4-1/0 gauge wire
3. An EXTRA wire from the positive battery terminal, fused, to the Positive alternaotr post...once again 4-1/0 gauge wire

If the Big three does not work...which it probably will (sovles 90% of the problems), then i would upgrade the alternator...maybe a 200 amp alt. Nothing huge, because obviously you arent going to be pulling 200 amps consistantly.

Now, if you are pusing 10,000 watts or above, a capacitor is a great Idea. 10 Farad and up is probably where they will start making a difference


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## adrian76 (Apr 19, 2004)

Punkrocka436 said:


> CAPACITORS DONT DO SHIT....I REPEAT...CAPACITORS DONT DO SHIT.
> 
> Do not buy into the hype about capacitors, unless you are talking about 40 farads. Before you look at going into a new alternator...try upgrading the big three first
> 
> ...


I agree, I've done 4AWG wire from the battery to the body. Another 4AWG wire from the alternator to the body. I'm waiting to do the extra positive wire (military life, I'm on the road now travelling). I do see more consistent output from the alternator now, from 13.8 to 14.3. BTW I've also put an Optima Red Top and I'm using all Streetwires conponents (batt. terminals, wires, ground block, etc.) Hope this helps.


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## Zac (Mar 10, 2004)

Try an Optima Yellow Top deep cycle battery. If that doesn't work, tack on another cap. If neither help, you may have to upgrade the alternator.


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## schebs240 (Apr 13, 2004)

Ok where to begin

alternator
What some people do not realize and seem to overlook all too often, your car is designed to run off a certain output, now if you have many old small frail wires, some in which at this point may be exposed, think about what will happen if you pump a large sum of elec... through there. CAN ANYONE SAY FIRE?? it's called a electrical overload, in order for a upgraded alternator to be used safely you need to upgrade all your wiring along with there fuses, because if not you'll be poping them.

2nd part alternator
if there is too much output to a battery it will begin to swell and smell like rotten eggs, next it splits and spills acid everywhere.

Dynamat? 
is it really necessary to spend $80 on sound dampening?? why not by some rubber trim for like 8 bucks from home depot and put that in, put some rubber behind your license plate and the rattle should be reduced drasticly.

capacitor
all I can tell you is that one will not hurt your car, it can only do nothing or benifit you. I can't tell you much without knowing what kind of a system you have? you only need a capacitator if you have more then 1 amp.


AS FOR POWER. all you need is a red top optima battery.. yellow is better for a large sum of audio equipment in which I doubt u have. go get a red top for $110.. you can leave ur lights on for 2 days and ur car will start right up.


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## sr20dem0n (Mar 19, 2003)

schebs240 said:


> Ok where to begin
> 
> alternator
> What some people do not realize and seem to overlook all too often, your car is designed to run off a certain output, now if you have many old small frail wires, some in which at this point may be exposed, think about what will happen if you pump a large sum of elec... through there. CAN ANYONE SAY FIRE?? it's called a electrical overload, in order for a upgraded alternator to be used safely you need to upgrade all your wiring along with there fuses, because if not you'll be poping them.
> ...


Where to begin....

alternator - wtf are you talking about? First off, if your wires are exposed, you have some serious problems, and you need to rethink driving this car on the road at all, much less putting a system in it. Second, just because the main power source has the CAPABILITY of outputting more current at the same voltage, that doesn't mean more current will actually flow out of it, and it especially doesn't mean that more current will flow to all of your normal electrical devices. Your headlights, interior lights, fans, etc will always take the same amount of power, whether your alt is rated at 80 amp or 300 amp, so your fuses will never blow unless you have a problem that would cause them to blow anyway. The only fuse that this doesn't apply to is the one in the alt + to batt + cable, which should be upgraded before you get a new alternator anyway.

alternator part 2 - again, wtf are you talking about? If your amps all of a sudden need 200 amps of current to play what they want to play, that power comes straight from the alternator, to the batt + terminal, and straight to the amps, it never goes into the battery at all. Unless your alternator puts out a significantly higher VOLTAGE, your battery will never explode.

dynomat - apparently you have no idea what sound deadening material is used for, so just stop now

capacitor - sure it can't hurt, but if it costs over $100 and doesn't do a damn thing then what's the point? And what's this about only needing one if you have more than one amp? If they really did what they say they do (which they don't 9 times out of 10), it would help just as much if you had 1 2000 watt amp or 2 1000 watt amps. What does the number of amps you have in your system have to do with anything?


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## schebs240 (Apr 13, 2004)

Any power source should be able to support any normal amplifier, without a capacitor.
it is really only really needed with 2 amplifiers..

I do know what sound dampering is used for but it's not really worth that much money if you have a rattle. The kid has a rattle not a need to contain the sound.

Alternator, read upgraded alternators are not recomended for regular street car use.

Exposed wires? hummm if you have a 95 which is almost 10 years old... humm wires tend to become frail old and exposed, in places you never see.

Yet like I said theres to many CONS to doing this for example

Upgrading to a larger alternator will combat this problem. The biggest problem is finding one that'll fit, since there are no direct fit high output alternators. However, usually mounting the unit is the most difficult problem. You may need to adjust the custom alternator mount, or fabricate a completely new one. You may also need a new belt, depending on if you use the original pulley or not.

The main concern when upgrading to a larger alternator is output at idle. Many high output alternators may promote output values such as 130-amps or higher, yet the values are usually when the engine is at a higher rpm. Often high output alternators actually have a lower output then stock alternators when the engine is at idle. The high output alternator may not put out enough power if all the vehicle's accessories are on and the engine's been idling for too long.

also why not just upgrade the battery. Optima batteries are the most popular high performance batteries available. Their SpiralCell technology provides the lowest internal resistance of any 12 volt battery. They use thin high purity plates, wound tightly to provide closer plate space, more surface area, and more power. Their unique design allows you to run your car's electrical options with the engine off for extended periods of time with the ability to quickly recharge when the power does drop. 


Plus check ur belt make sure it's not loose.

SR20 demon why don't u try being a little nicer with ur comments, because I try to give a little help from what I know and u come back at me like I'm some kind of idiot. Don't be such a wise azz. Why don't u take ur attitude out on people who post things like I need a upper radiator hose and don't post a car or location. 
Doug


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## Zac (Mar 10, 2004)

If you don't feel like bothering with a new battery or alternator, lightning audio released a 25 farad cap for like 250 bucks. I have not used and I don't know anyone who has. http://www.sounddomain.com/sku/LITSCC25


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## sr20dem0n (Mar 19, 2003)

*Any power source should be able to support any normal amplifier, without a capacitor.
it is really only really needed with 2 amplifiers..*
That completely depends on the power of the amps, it has absolutely nothing to do with the number you have. You could have 1 1500 watt amp, or you could have 2 300 watt amps. Obviously the 1500 will be a much larger strain than the 300's, even though there's only 1 amp. I know now that you meant the current required to overload the electrical system normally isn't high enough unless you have 2 amps, but blanket statements like this really confuse people and throw them off, especially people that don't know what's going on.

*I do know what sound dampering is used for but it's not really worth that much money if you have a rattle. The kid has a rattle not a need to contain the sound.*
A lot of times the rattle isn't the seal where the trunk rests, that's part of it, but not nearly all. Trying to patch everything up with some rubber trim will take forever, especially if it's the spoiler or the trunk itself rattling. It's much better to go at the source, and that's to kill the vibrations entirely, not only will this keep the bass from being transmitted outside the car (less people know you have a system, so less chance of theft), it will also kill the rattles right then and there. Dynomat is a waste of money IMO, but there are many other vibration dampening alternatives that cost much less and do the job just as well.

*Exposed wires? hummm if you have a 95 which is almost 10 years old... humm wires tend to become frail old and exposed, in places you never see.*
This may or may not be true, I haven't taken apart a 10 year old car and inspected the wires, so I really don't know. I still don't see how this applies to upgrading the alternator though. Only one wire will carry more current if you have a HO alt, and that's the alt to batt + wire. This should be upgraded already along with the rest of the big 3 before a cap, battery, or alternator are even considered. Besides, how does the hole in the insulation have to do with the thermal current capacity of the wire?

*SR20 demon why don't u try being a little nicer with ur comments, because I try to give a little help from what I know and u come back at me like I'm some kind of idiot. Don't be such a wise azz. Why don't u take ur attitude out on people who post things like I need a upper radiator hose and don't post a car or location.*
Sorry if I came off as harsh, actually I kinda did, but you pushed one of my buttons. Whether you knew what was going on or not (which it appears you did), the way you worded it would really throw off someone who didn't know better. You might know the background, or what you really meant by what you said, but someone who doesn't know any better might not, and taken by themselves your comments tend to be misleading and give the wrong impression of how things work or what things really do.

As for the original poster, listen to what Punkrocka said and upgrade the magic 3 first. This will have atleast as much of an impact as a cap, costs much less, and it WILL help (as opposed to "might help") both your dimming and the car's electrical system as a whole. After you do that, if you still have problems (which I doubt, from a 475rms amp) you might want to take a closer look at the gain setting, or get your alternator checked out at Autozone. If neither of those are successful, I would recommend going after the battery next.


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## schebs240 (Apr 13, 2004)

I appreciate you being a real man unlike most people on forums, and knowing when U where wrong. 
Yet if I was misleading I am sorry, because sometimes when I describe things, I describe them from my Point of view.

I like this forum and have no intentions of starting any flame wars. So i really do apprecitae u not going off.

As for sound dampining, what do you recommend, i put 2 12's and all hole Sh!t load of stuff in my brothers sentra last night.

Also On the 2 rear speakers, I have a red and a green wire. Red is positive correct? and on the speaker the 2 contacts the larger one is for positive correct?


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## sr20dem0n (Mar 19, 2003)

For sound dampening, really a layer or 2 on the trunk lid should be all you need to kill rattles. It does look like crap when you open the trunk if you don't cover the mat in anything, but IMO it's worth it. I can turn my sub up as loud as I can (somewhere around 140dB, it's painful to be in the car with it), get out of the car with the windows up and the doors closed and not hear a single rattle, other than the f*cking door handles....I hate those things, of course when the door skin on all 4 doors is flexing a good half inch I guess it's hard to keep all the rattles at bay.

Anyway, the license plate is the real problem, but you apparently know how to take care of that. I just put a later of mat on the backside, and then a ring of weatherstripping (foam with adhesive on one side, simple stuff) along the outside edge, which shut it up well. I still haven't managed to get rid of all the interior rattles yet, most of them are gone, but the problem is that when you get rid of all the big ones, you all of a sudden hear twice as many small ones that you never knew were there before...*shrug*

Not a clue on the rear speaker wires, I suggest you take a 9V battery and touch it to the terminals on the speaker. If the cone moves out, you have it right (batt + is on the speaker +), if the cone moves in, you have it backwards. If you have enough stock wire attached to the speaker you can do this on the stock speaker as well to figure out which color wire is which.


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## schebs240 (Apr 13, 2004)

Cool thanks, As for ur minor small rattles... Unless you simply pull everything apart and tighten everything u'll never get it all..

I have 2 10's in my 240sx hatchback and the only rattles i get is a part of the spoiler, in which I can't stop unless I grab it and hold it.... And i haven't done anything to the car it just doesn't vibrate.. I'm loven it...


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## Punkrocka436 (Jul 8, 2003)

schebs240 said:


> I have 2 10's in my 240sx hatchback and the only rattles i get is a part of the spoiler, in which I can't stop unless I grab it and hold it.... And i haven't done anything to the car it just doesn't vibrate.. I'm loven it...


Take the spoiler off and affix some dampening to the underside of the posts that the screws go into, that will take care of it. Good for you not having rattles though, my door panels rattle like hell...secondskin is getting a call from me soon


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## sr20dem0n (Mar 19, 2003)

Yeah, you're one lucky bastard to not have any rattles 

Being lowered with i/h/e and motor mounts led to a bunch of mine though, so I guess I can't complain too bad seeing how I caused most of them myself...


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## schebs240 (Apr 13, 2004)

My spoiler is actualy double reinfored with stainless steal plates 8inch by 4 inch which are also bolted and siliconed to the car. there is all gaskets between all peices of metal, i would consider sound dampining the trunk but its a hatch its tight and small space with a motor inside of it for the wiper arm.


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## schebs240 (Apr 13, 2004)

ok for upgraded alternators that are free shipping no tax and price negotiable go here and call and ask 4 dave.

http://nexxon.com/catalog/index.php?cPath=132_196&osCsid=9f4decae7f5d7b7e22cf3220e7407b52


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