I'm gonna be setting up my new system and i want to make sure the stock alternator can handle the wattage. I will be running a phoenix gold octane-r 8.0:1 rated at 800Wx1 (2ohm) and an phoenix gold octane-r 5.0:4 rated at 80wx4 (4ohm). I think the 5.0:4 is 40-50watt rms x4. I will also be runnin a 150watt opus dc power supply to run my carputer.

I currently have a 400watt inverter running my carputer and a 1200watt crap boss amp and have absolutely no problems.

What do you think of with the upgraded system? any suggestions?

 

there was a point when i had 2 kicker 1200.1's pushing 2 hifonics atlas square subs with no problems well the lights dimmed and the rear quearters shivered like a chihuahua but other then that the car ran fine i didnt notice any hezitation when driving fast and when it ideled it sounded fine also

 

Sounds oddly firmiliar...

I have a 400W interverter running my car-puter in the Paseo (but not sure on the wattage of the amp) You should be fine. Only I don't run my computer much at all.

 

aaron, u do anything to solve the light dimming problem? put in a capacitor at all or you just didn't care all that much?

 

no i didnt becouse i didnt have it in for long i had to sell it all when i had got laid off but now i have a new job so im shopping around for a new setup this time i want some thing that looks nice and not something that shakes the ____ out of my whole car im thinking 2 type r's or 2 130.v2 subs from elemental designs and a kicker sx1250.1 to run the subs im not sure if ill buy them this summer or focus on performance this summer and get the subs and amp in the fall but its definatly that amp and one of the two pairs of subs that i will be going with probly the edesign becouse i dotn see any one with them around here

 

the ED's will sound better than the type r's anyway....

 

The issue you will face (regarding the alternator) if running at high volumes alot will be a decrease in alternator life (at minimum) . The alternator has to supply all of the vehicles current needs as well as enough to charge the battery. You are looking at adding around 70 amps extra (if I read your numbers correctly) at max output. However.. your amps will most likely never be pushing that amount of power continuously (or even at short bursts). So you will probably be ok. I would let it run and see how it does.. It will most likely reduce alternator life, in which case you would want a higher capacity setup. Better batteries will not reduce the effect on alternator life due to the alternator having to supply the needed current while the car is running.

As far as the lights dimming.. the answer to that is usually a capacitor. Caps respond much more quickly to transients than batteries which is why they work so well. An alternator is not the answer to that issue. Without going into the physics behind them... the cap is basically acting as a high pass filter which smooths out these transient spikes in the line voltage which are causing the lights to flicker.

 

A cap is really just a band-aid fix for an electrical issue. I reccomend upgrading your power and ground wires under the hood (known as the big 3) - this should help the dimming problem.

 

a small trick i learned is that when ur driving at night and ur bumpin hardcore, dim everything inside that way ur alt wont have to give so much power to ur other stuff and u can be bumping hardcore. i know its prolly not much...but im sure every bit counts

 

A cap is a very effective fix for certain types of flickering issues. A battery cannot respond to transients in the way a cap can. Short dimming, or flickering, of the lights is easily solved with a cap and will most likely not be effected by better grounding or cabling. Sorry to sound like I am arguing.. but I the nickname comes from my background in electronics engineering, so I am not arguing, simply stating correct information.

Current is drawn from ground, through the chasis, to the electric devices and then back to the positive side of your battery. So, if you are drawing too much constantly (causing the lights to be dim all the time while everything is on) you are requiring more current than the alternator can supply to the system and will eventually destroy the alternator (better grounding and cabling will help this minimally). The time it takes to damage it depends on the system and how often it is run at high levels.

If you are seeing the lights dim only when the bass is hitting very hard at high levels, then you are experiencing a more transient issue. The peaks of the signal produced by the amplifier are approaching the limits of the system for short durations, which the battery and charging system cannot respond to quickly enough, so you are seeing an AC signal superimposed on your power circuit, which shows up as short dimming of the lights. A cap will help to smooth this out to avoid the issue. Better grounding will not do much for this.

Now, grounding and cabling works wonders for signal integrity, as higher resistance wiring and connections increase the transmission of noise signals.

 

I do agree that a cap can be useful, the problem is that they often tend to be misused. They have their purpose for sure, but lots of people like to "balance" out an inadequate electical system with caps. Here is quite a discussion from another forum:
http://forums.caraudio.com/vb/showth...hlight=useless

 

I think we are both hitting at the same thing from different sides. Most of the anti-cap guys on that forum were talking about severe dimming due to 2 - 3 sec sags in power.. which is a little more of an issue. In those cases a modified charging system is definitely needed. The less extreme cases are not enough to seriously damage the alternator and can be corrected with properly sized caps. Like I said, we are more or less agreeing in the sense that it depends on how extreme the application is and the type of power issue one is adressing.

 

Yeah I think so... One thing you need to remember is that most of the time you arent running your system 100% anyways, so the current draw is much more managable. If your somebody who is always pushing 100% (with some serious amps mind you), there is more needed in the whole electrical equation than just a cap

 

I = need for a full electrical system.

Max RMS wattage of new system ~4kW

Your stock alt will be fine with that set up...and probably not even need a cap. I ran a 2300 watt setup through the stock system...only had dimming when it was so loud I hated it ;)

 

Stock Scion xB owner here, ready to begin modding.

Stereo was first, pulled out stock, put in Pioneer's AVIC-N2. (Anyone know the GPS while you drive fix for this one BTW?)
Sirrus Sat radio installed
Replaced rearview monitor with rearview camera and LCD
Limo-tinted rearwindows to Virginia law specs
Added Streetglow under body Neon
Modded dash clock to match Blue color scheme
Modded dash tach and speedo to match Blue color scheme
Niche rims and low profile tires
I've purchased 4 Pioneer TS-W256DVS 10" subs to go into a custom box I'll fabricate.

Okay, so now that you know what I got, here's my question for the geniuses here:

I've been thinking of purchasing 4 PIONEER PREMIER GM-7150M amps. They're rated like this:
2-8 Ohm Operation
250 Watts RMS x 1 @ 4 ohm
360 Watts RMS x 1 @ 2 ohm
800 Watts Peak

What will I need to do to power this configuration? Upgrade my alternator? Purchase caps? Rewire my electrical system? Plug it up to stock and just pray ?

I don't know what the stock alternator output is for an xB and I don't really know what I would do with that information if I did have it.

Any ideas / information would be HIGHLY appreciated. I'm wanting to finish this project within the next couple of weeks.

Thanks guys!