Help with new alternator

[drtylggy]

I'm looking into getting a new wrx 140 amp alternator. I've been asking around to see if they bolt right in but someone mentioned a "Big 3 Power Mod". :shock: I've been looking all over about it but can't seem to find a difinative answer. :smt013 What does it do? How do I do it? Is it worth it?

Also as a side note, I'm still running my stock alternator and battery from my 04 35th Ann. Do I need to replace wires for amp upgrade or need to battery to cope with the amps?

[Okin DaVanh]

don't know about the big 3, but a couple of links here:
viewtopic.php?f=10&t=21531 (https://sl-i.net/FORUM/viewtopic.php?f=10&t=21531)
are a good read.

And what does your system consist of?

[drtylggy]

Yeah, I was reading through that but our stock ones are 90amp so I don't see why STI was brought up. Also I have been told that it should bolt and plug right in. :smt023

[Okin DaVanh]

uhmmmm.. re-read it. Says somewhere there, that you "might" have to chop and swap harnesses IIRC

[02_Legacy]

I really doubt you will need a high output alternator unless you have a huge system. If you are a 14 V and your alternator is putting out 90A that means you have to be pushing 1260 Watts before you are drawing more than your alt is putting out. If you are worried a capacitor should be all you need.
A new battery is probably a good idea if you have the stock one still in. Again if you are worried you could get a high performance AGM battery. If you do a search we just had a dicussion on this a few weeks ago.
And the Big 3 mod is upgrading the wires between your alternator and battery, battery and chassis ground, and battery to block ground to reduce resistance in these circuits.

[Okin DaVanh]

^-- This. I was also going to suggest the "Grounding" mod, but this is something similar. Didn't know there was a nickname for it now. Man, I've been out the loop.

[drtylggy]

Well I was looking into a bigger alternator because after adding HIDs the fog light would flicker to the alternator and now the headlights are dropping from 8k to 6k, and I know it's not the HIDs. So you think it could be just a bad alt. and just get a stock OEM?

[Wiscon_Mark]

If you think you have a bad alternator, go to an auto parts store (autozone, advance, oreilleys, etc) and have your alternator & battery tested. It's free.

HIDs actually use less or comparable wattage to standard Halogen bulbs, so I don't think that's it either.