heavier alternator

[baracuda]

im led to believe that cop cars have a heavier alternator in there vehicles to run all the gizmos they got.can this alternator be purchased through holden and bolted straight in? or will it upset the brain etc etc??

[accentstencil]

You should be able to get it from Holden or places like Repco and it will bolt straight in and won't cause any issues with the computer.
I believe it is a Mitsubishi 120 amp alternator.

[baracuda]

Great!!! thanks i'll chase it up and see what they going to slug me for it.
much apreciated

Originally Posted by accentstencil

You should be able to get it from Holden or places like Repco and it will bolt straight in and won't cause any issues with the computer.
I believe it is a Mitsubishi 120 amp alternator.

[kopper69]

You only need to upgrade your alternator if you are really draining the power while the car is running. Using a multimeter, measure the battery voltage while you turn all the accessories on and see what sits at. Let us know the result. A bigger alternator isnt going to make the battery last any longer when the car is turned off or make the car easier to start.

The alternator only works as hard as it has to, to keep the system at the set voltage. If your stock alternator under normal conditions is only putting out 30A, putting a new alternator in wont make any difference as it too will only put out 30A. A bigger alternator will simply charge a battery a little bit faster or run extra accessories. You will loose a little bit of engine power as the alternator will take more away.

Just make sure that you really need it before you go spending the $.

[.]

and honestly...if it's pretty expensive, consider getting a Stinger Alternator or similar. Good for 200A

[VZ SV6 Ute]

so basically switch everything on, see how much of a voltage drop there is and then consider doin the upgrade if voltage drop too significant,
currently my added accessories
2x 100 w spotlights, (16.6A)
extra dual cigarette lighter/outlet capped at 15A
uhf cb & maglite charger (10A max)
and in the process of adding 300w 12VDC->240VAC inverter (35A Max)
when i turn the spotlights on i do notice a decent voltage drop at idle but once revs are built up voltage drop is removed,
justy goin to see what happens when i wire up the inverter and draw full load, will be interesting,

[road warrior]

What was the altermato rated at? If you are keeping the standard sterio unit you shouldnt need to upgrade the alternator. Car manufacturers only ever fit alternators that will only just cover the demand for power supply. It could be considered changing the alternator if you change the head deck. but its when you start adding things like subs and amps that you really have a draw on your battery. My last car I could flatten the battery in less then an hour 60amp alternator with a 100watt amplifier hooked up after being turned o full power for about half an hour the sterio started to lose volume.

[kopper69]

Originally Posted by road warrior

What was the altermato rated at? If you are keeping the standard sterio unit you shouldnt need to upgrade the alternator. Car manufacturers only ever fit alternators that will only just cover the demand for power supply. It could be considered changing the alternator if you change the head deck. but its when you start adding things like subs and amps that you really have a draw on your battery. My last car I could flatten the battery in less then an hour 60amp alternator with a 100watt amplifier hooked up after being turned o full power for about half an hour the sterio started to lose volume.

Not really true. Stock alternators provide more than enough current for the stock system. Adding an aftermarket head unit in wont make an ounce of difference and adding a reasonable sound system is normally still covered by the stock alternator. Once the car is off the battery isnt going to last any longer no matter how big the alternator is.

[.]

I typically don't start talking to my customers about upgrading alternators until we hit 150A PEAK draw...

[road warrior]

Originally Posted by kopper69

Not really true. Stock alternators provide more than enough current for the stock system. Adding an aftermarket head unit in wont make an ounce of difference and adding a reasonable sound system is normally still covered by the stock alternator. Once the car is off the battery isnt going to last any longer no matter how big the alternator is.

Just speaking from experience. Not sure what differences they have between a 1981car and a 1990ish car but (It could have just been my car) I could watch my amp meter get progressively lower as I drove.

[SAV_117]

wat do u guys suggest if there is off and u want to say liek play your ps2 in the car lol how much would that drain and how could u make it last longer better battry??? or yeah i dunno

[centy]

there are many ways to set it up.
dual battery
larger deep cycle battery
More power effective accessories (hid bulbs, gold plated connectors)
If you want to run the accesories with the car off then you need dual batteries.
set one up just to run the selected items.
When it goes flat you will need to start the car to charge it.

[SAV_117]

hmm sounds like plan may start to think of dual setup

[centy]

to run the ps2 while the car is off put a deep cycle battery in the boot and the easiest thing to hook it up would be the diode system as it charges up as soon as the alternator starts to charge.