Increase alternator output or adjust idle?

[mazilla]

I bought a Rockford Fosgate T1 10" and tossed it in the Yaris with an Alpine PDX1.600. @ idle I'm losing a good amount of RPM's with each drop. I know it's normal for the Yaris to find the lowest idle possible for fuel consumption, and I also know the 80 amp alternator is so so(although I thought it would be enough for such a small car to add the stereo). I'm worried I will stall one day when the A/C is running, the cooling fan kicks on and the bass drops at a stop light or in LA traffic.


My question is, if I have my alternator re-wound to 160amp (or so) will I run into trouble with the excess juice...I mean how much more could the 600W class D mono amp need? I'm on the fence between the alternator, and messing with the idle.

The battery is random auto parts store(without looking) it's probably 500 CCa or something similar. Eventually I'll swap the battery with something proper, the one in there is only about 8 months old and shows correct volts. Each of my other cars has a red top in it so I can pull one and see if it'll help, but I doubt it will.

The other cars I did alternator work to had substantial systems so I knew the high output would be used up, the Yaris I'm not so sure about.

Thanks.

[derickveliz2]

What about a "BIG 3"

I'm running 3 amps at the same time and I have no problems.

D.

[sqcomp]

We have drop in units at DC Power and a universal unit from powerbastards available.

[mazilla]

Originally Posted by derickveliz2

What about a "BIG 3"

I'm running 3 amps at the same time and I have no problems.

D.

I did a ground kit a while back, I'll try and piggyback some power wire and see if it helps. I can't get to it until the weekend.


Also, I upgraded my 10 to a Fosgate T1 this evening...sooo much better.

[MGargano]

If you're interested, I have a custom-made NST 10% overdrive alternator pulley for sale that might help you out

[mazilla]

Originally Posted by MGargano

If you're interested, I have a custom-made NST 10% overdrive alternator pulley for sale that might help you out

I am interested, shoot me a PM with the details. I was looking into this pulley as well...

Right now I'm losing about 300RPM on a steady low bass drop. I'm a heartbeat away from grabbing a junkyard alternator tomorrow and giving it to a local shop(who's done work for me before)...just worried about all the extra output. If I could get an answer to that I'd be stoked. Anybody??

[CTScott]

Originally Posted by mazilla

I am interested, shoot me a PM with the details. I was looking into this pulley as well...

Right now I'm losing about 300RPM on a steady low bass drop. I'm a heartbeat away from grabbing a junkyard alternator tomorrow and giving it to a local shop(who's done work for me before)...just worried about all the extra output. If I could get an answer to that I'd be stoked. Anybody??

The overdrive pulley should help. Also, a higher amp-hour capacity battery would help as well. With a rewound alternator, the extra output will not be an issue. The higher output alternator will really only put a heavier load on the engine when the higher current demand is occurring. In normal operation the field current difference between the stock and rewound will be insignificant. The stock 70A winding probably has a field current of about 2A and a 100A rewound might increase to a field current of 3A.

[sqcomp]

Out of curiosity, why would a battery help if it's not making the vehicle's power after it starts?

[mazilla]

Originally Posted by CTScott

The overdrive pulley should help. Also, a higher amp-hour capacity battery would help as well. With a rewound alternator, the extra output will not be an issue. The higher output alternator will really only put a heavier load on the engine when the higher current demand is occurring. In normal operation the field current difference between the stock and rewound will be insignificant. The stock 70A winding probably has a field current of about 2A and a 100A rewound might increase to a field current of 3A.

Awesome sauce. I bought a used alternator from the scrapyard(same place I found that other members car) and took it to the alternator shop. I asked for 120A(hopefully we're still good) and a 10% pulley. Ended up being 175.00(plus the 50.00 for the core)...should be ready by Wed.

[CTScott]

Originally Posted by sqcomp

Out of curiosity, why would a battery help if it's not making the vehicle's power after it starts?

The battery is basically a capacitor once the car is running. It keeps the voltage from sagging too far if the alternator can't source enough current. The problem is that the stock battery and alternator combo are sized for just the standard load. If you run equipment that draws more than stock, you will find that after starting the battery will take a few minutes or so to get back to a full charge.

[sqcomp]

Indeed...at that point you're killing the alternator. This is why you should never have to even get to 12.6 Volts. If you're going to be slapping that much draw on the alternator, a battery is just a band aid...and another load for the alternator to charge.