legacycentral bbs

I used to be a stereo installer so I know alot about car audio, but I never got big into caps.

The amps I am using now will dim the headlights anything past halfway on the dial. I am thinking about buying a cap but I have seen installs where people just use a second battery instead of a cap.

I am adding a 600watt inverter so I could benefit from a 2nd battery.

I have a brand new battery sitting in my garage that I could easily install in the wagon.

Any opinions?

What gauge wire you running to the amps, and what is the max combined amp draw for the amps?

What battery you have?

I've got a 1 farad cap and the optima yellow top. I'd probably be fine with just the yellow top, but caps are relatively cheap. I think I got my 1 farad RF for about 100 bucks back in the day.

Other thing you need to remember is that your alternator only outputs like 70 amps. So if you're sucking more then 70 amps, so if you're running around sucking more then that for a long time, the battery isn't going to be charging adequately, which makes the problems worse.......

Caps are for surges in power draw from the amp, like a beat. If you listen to music with like "constant bass" the cap won't have any time to recharge itself. If you add a second battery it will add stress to your alternator. Make sure your battery connections are good, and also the ground wire connection. One thing alot of people forget is to have your ground wire the same guage as your power wire. Another thing to do is add a bigger output wire from the alternator to the battery, athough I heard this can cuase a draw from the battery on Subarus.

I have a top of the line diehard battery. I run 1 guage to the rear where it is split up in a fused block to (4) 10 guage wires. I use the same method for grounding except with no fuses.

I run 1000watts RMS 1400watts peak.

800RMS to subs and 200RMS to 4 kenwood 6.5's

Do they make a high-output amp? I bet it would be 300.00 if they did.


I think I might run a dual battery isolator and install an on-board charger. The kind you just plug in when you are around 110v

Binford, I've added beefier wires from the alternator to the battery, and beefed up the ground wires too. It doesn't cause any sort of drain.

legacycontinues, What is the max amperage draw for your amps?

I do have a HO alternator, and yes it's a little over 300 bucks, and requires modifying the wiring, because it's meant for a newer subaru.

The main power lead needs to be extended about an inch, and the plug style changed. The HO one also uses an rpm sensor to turn on, vs ours, which is ignition turn on.

The only other issue with HO alternators is that at lower rpms their output is less then conventional alternators.

I am not sure how many amps it is drawing but I will tell you what I do know.

My sub amp has (4) 30amp fuses
My mids and highs amp has (2) 30 amp fuses

I rarely push these amps over the edge as they supply ample power.

Max amperage draw that they're probably capable of is somewhere around 180 amps, however in reality, it won't be that high....but it will still probably be at least 50-70 amps at high musical/bass load, which is probably stretching the alternator, especially if it's old/worn.

Cap always helps. Keeps the bass cleaner, too. 1 Farads can be picked up on the cheap.

The alt is an OEM Subaru that I purchased only a few months ago after my original finally gave up the ghost.

My car only idles at 500rpms.. Should I crank it up to 1K?

I cranked the revs up to 1K and installed a 12volt sealed battery like you would find in UPS (battery back-ups)

Seems to do the trick.

What do you mean you cranked the revs up to 1k?

The legacy has been idling around 500rpms after I cleaned the TB out with carb cleaner. I turned it back up to 1K and the CEL turned off and hasn't come back since.

How did you turn it up to 1k?

Did you check to see what code was causing the CEL to come on?

Idle set screw.

I'm not going to get into a big long post....but you really shouldn't touch that.

I had to. The car was idling so low that it acted like it was going to stall out all the time. It would shake so bad it made my wife and I sick on more than one occasion.

Subaru's funny like this: There's all these parts on the car that you can touch, and mess with, and do things to, but FOR THE LOVE OF GOD, ALLAH, BUDDAH, AND ALL THAT IS SUBARU-HOLY, DON'T TOUCH THAT SCREW!!!
Yesh, it's factory-set, and hopefully yours still has the paint on it, otherwise, it needs to get set back to factory specs.

Subaru-haiku-Subaru:
So much depends on the little painted screw
that rests serenly upon the butterfly...

You know that the first tickmark on the tach is about 700 RPM, not 500, right?

The engine should idle fairly smoothly at about 700 RPM. If it doesn't, you can mask the problem by adjusting the throttle stop screw, but that can cause driveability problems since the IAC valve control goes nutty. It'd probably be better to fix the problem that was causing the rough idle.

Lets put it into perspective that this car is a 1990 with a billion miles that I paid $700.00 for 20K ago. I am not racing it. I don't drive it across country either. It goes from point A to point B. I would prefer it gets me there without making me toss my cookies.

I change the oil, rotate and balance the tires and fix things when they break. I am not too concerned with drivability. If and when I purchase a new Roo I will keep that in mind.

So unless you know of another was to turn the idle up besides touching the "idle set screw".....I am all ears. If it involves replacing some part that will clean my bank account out then you can scratch that notion. I could put that money towards a new car. I would have to be sick in the head to drop money into a 1990 anything.

(I just read what I wrote, please forgive me if it comes of rude in any way, shape, or form as I truely did not mean for it to sound that way)

Well, what I'm saying is that an increase in idle speed shouldn't be necessary to keep your lunch down. It wasn't clear that you were aware of that. If you do, though, and don't feel like fixing the root problem, though, that's your call.

If the first notch is 700 then it was on 700 and idling like shit. It idles slightly over 1K now and I feel that this will benefit me in the amps department. Seeing as to how I run 1400 watts in amps and a 1200 watt power inverter. (not at the same time...yet)


I do thank everyone for their input though.

Sure..
Besides, considering what you're running in there.. --cd player, amps, subs, fuckin' 'puter.. Well, your idle needs to be a tad higher, and the adjustment you chose seems to me to be the best way. Any other 'root' of the problem, as V puts it, might be trivial. That analysis might not have taken into account all your accessories.