High output alternator, which size?

[rotwiler]

I have the stock Monsoon amp and speakers and soon to do Infinity's in front using the Monsoon amp. I have a MTX 2150x which in a 4 ohm load is around 450 watts rms. I also have the largest Optima red top I could fit without modifications into my 02 Z28 and a 2 farad capacitor(which does very little). I ran 2 JL audio 10's (10w0) and they were pretty efficient subs, but finally fried them when my battery was going out and voltage dropped to like 9 volts. So, I bought 2 Memphis Audio PR 10 DVC's and wired them to see a 4 ohm load. They don't seem as efficient as the JL audios, but they do produce deeper bass and they seem to handle the MTX amp better. Problem now is at a idle the voltage drops from 14 area to 11 area and I have to turn the volume down alot to be safe, anything above 900 rpms and the voltage stays above 13 volts, so now was wondering if a higher output alternator would cure this problem. Also I may in future move up to a 800 watts rms and get some Memphis M3 subs and want to be ready to go. Would a 235 amp alternator be good in my situation(isn't stock 160?), I figured it would give me a extra 75 useable amps which would easily handle the load from the 450 watts rms amp, but not sure about a 800 watts rms amp. Most likely I wouldn't be able to listen to it turned up as far as with the setup now, because it is now at my listening limit, much more and I may lose hearing, but with a higher rms amp I don't want it clipping and frying subs. Even if I don't get a bigger sub amp I may get a 75 watts x4 amp to run the door and sail panel speakers.

[White Rascal]

An HO alt can only help. I would pull the 2 Farad capacitor. It's doing more harm than good. The important thing to look at when considering an HO alt is it's output at idle. Once up to speed most alts will provide enough current to power everything. It's when your car is at idle and the RPM's are down that you notice dimming lights on loud bass hits. This is where you need an HO alt with high output at low RPM's.

I've been thinking about getting an alt from Excessive Amperage (http://www.excessiveamperage.com/) for a long time now. Their alts are designed to kick in at 900 RPM's. It's been a while since I've been looked into an HO alt so there's probably other options out there.

[1QuikWS6]

Another good place to get hi-amp alternators is thru AfterThoughts Auto - they sell 160 & 200A versions that are made by Mr. Alternator which is a reputable alternator builder. I have the 160A version, powdercoated to look like chrome in my WS6.

[mdh100]

make sure whatever alternator you buy is rated at idle. if a 200 amp alternator is rated at 2k rpms then it doesn't do you much good. Also, I know many people that run a lot more power than you and still have their stock alternator. There's quite a few people that run 1500+ wrms. Although their alternator will obviously need to be replaced much sooner. BTW your subs didn't blow because your voltage dropped. Your subs probably died because the low voltage to your amp.

[White Rascal]

How does low voltage to the amp blow the subwoofer?

[mdh100]

once your voltage dropped to your amp the amp quit sending clean power to your subs

[ScrapMaker]

you would be able to hear the distortion WAY before you damaged your woofers though..

[mdh100]

you would be able to hear the distortion WAY before you damaged your woofers though..


true...but prolonged use would still cause damage and you'd be surprised how many people damage their speakers this way.

[ScrapMaker]

this is the same way people blow their stock monsoon speakers... not from power... but from crappy distortion.

How do people do this? It astonishes me. I can't stand the way distortion sounds... I guess I have it easy... a lot of people from the ghetto seem to either 1) love that sound, or 2) have no idea that this is the reason their $30 Jensen speakers keep assploding every week.

Can anyone recommend the 200A powermaster alt? it claims 120A @ idle, and 200+ @ highway....

I'd rather have one that put out like 180 @ idle and the rest at like 1000RPM

[mdh100]

true...but prolonged use would still cause damage and you'd be surprised how many people damage their speakers this way.

I agree that you'll be able to hear the distortion....but many people don't...I constantly complain when I'm in other people cars about their mids/subs/etc bottoming out which could be fixed with a simple twist of the eq nob.

[mdh100]

this is the same way people blow their stock monsoon speakers... not from power... but from crappy distortion.

How do people do this? It astonishes me. I can't stand the way distortion sounds... I guess I have it easy... a lot of people from the ghetto seem to either 1) love that sound, or 2) have no idea that this is the reason their $30 Jensen speakers keep assploding every week.

Can anyone recommend the 200A powermaster alt? it claims 120A @ idle, and 200+ @ highway....

I'd rather have one that put out like 180 @ idle and the rest at like 1000RPM

I'd go with a powermaster or ohio generator....have you given Iraggi Alts a look?

[ScrapMaker]

hrm, looks like if I went with Irraggi, the best I can get in our CS130 casing is the 200 Amp "Amputator" 200 hwy/120 idle.

$300 + $99 warranty + shipping... wow! expensive

does anyone know for sure if the "Large Late-Model GM" alternator on Powermaster's website is the CS130 casing we need? or can we also use the CS144 no problem?

Amputator 200A (http://cgi.ebay.com/200amp-Amputator-Series-Alternator-Chevy-GMC-Pontiac_W0QQitemZ5758166242QQcategoryZ14932QQcmdZV iewItem)

LARGE! Powermaster GM Late-Model (http://www.powermastermotorsports.com/gm_late_model.html) (scroll to bottom)

It sounds to me like I'd get a better warranty from Powermaster (through some retailer... maybe Summit?? I don't know where to find these alternators) than I would with the Iraggi.

I don't ever plan on competing or anything, I just want my system to be able to perform at it's best, when I want it to.

[rotwiler]

I agree that you'll be able to hear the distortion....but many people don't...I constantly complain when I'm in other people cars about their mids/subs/etc bottoming out which could be fixed with a simple twist of the eq nob.

I'm actaully the same way when in others cars and in my own when I can hear distortion or speakers bottoming out, but this time was a different. I put Akon and young Jeezy's new song which has some really strange sounding bass freq on a cd, not sure if you ever heard the song, but isn't normal sounding bass. Anyway, I drove about 2 blocks and noticed everytime the bass hit my voltage dropped and my gauge was sweeping, so I started to turn it down and was too late. I know it wasn't from prolong distortion, because the same 2 JL audio subs were in my car since 2002 and lasted 32,000 miles and had them in my previous 2000 Monte Carlo SS for 29k miles, I listen to them at high volume levels daily and was the day the battery went that the subs melted down. I know the amp I have is known to clip bad if not set up right, but I have many years of using it and know how to adjust it correctly. With this same amp in 1999, I had a Solabaric single 12 and the same thing happened in another car when the battery was weak. I'm not sure what the actual cause of the subs melting down was, but it has to be related to the bad battery.