Alternator Upgrade For Stupid Sound System

[MattMcGrathE30]

Looking to install a stupidly loud sound system, 2000-2500RMS on a 15" Orion HCCA Subwoofer, 75-200RMS front speakers, 100-200RMS rear speakers.

Im gonna do the obvious upgrades - 'Big 3' upgrade, Optima Yellow top battery, and then if it needs it, a spit charger and a second Yellow Top

The only thing left is an alternator upgrade, can't seem to find much online so I'm just hoping someone on here has already got a stupidly loud system

I have a 1991 325i SE if that makes any difference, if i remember correctly the alternator is 90A stock, but it just won't hack the power I'm going to need.

I found a post of someone doing a 140A swap from a 1992 735i but i can't seem to find anyone selling that particular alternator, and most breakers want to sell it complete with the engine. And even that swap needed a couple small modifications.

I came across 'Irraggi alternators', has anyone used one?

Any help is appreciated!

[bmw9818]

will a capacitor not suffice?

ive had a few set ups before in my hatchback days, had 2 12" ground zeros some pioneer 6 x9s and infinitys i think i had up front, two amps phonix gold and an splx, had a capacitor linked up and when the bass kicked in it really helped, as before driving down the road at night when the bass kicked in would dim the lights with the song!

that system pretty much shaked the car to death!...

but if you wanted to go for a higher output alternator im sure speaking with an alternator/ starter type specialist may have some advice,

[chu346]

will a capacitor not suffice?

[BadDave]

I have used a 140amp alt from an E38 with split charging.

I did have to modify the mountings and make up a mounting bracket to get it lined up with the PS/water pump pulleys.

[MattMcGrathE30]

I have used a 140amp alt from an E38 with split charging.

I did have to modify the mountings and make up a mounting bracket to get it lined up with the PS/water pump pulleys.

What engine was it? Would you be able to point me towards any guides or anything? Any help is much appreciated!

[BadDave]

I have used a 140amp alt from an E38 with split charging.

I did have to modify the mountings and make up a mounting bracket to get it lined up with the PS/water pump pulleys.

What engine was it? Would you be able to point me towards any guides or anything? Any help is much appreciated!

It was on an M20.
There wasn't any guides. It was just a case of making it fit.
I had to swap the pulley and use the one from the stock alternater.


I do remember having to make spacers and use a longerbolt to get it aligned correctly

[miniblob]

I would start with 'the big 3' and get the kit installed with good quality cabling and see if you really need it!!!

I've done it all before and its always aggro - and often, I've discovered, unnecessary!!!

I had so many probs with split chargers, I just gave up and used to run a pair of optimas in parallel, (daily drivers).
I've used capacitors, way back, and found them, mostly, to be pretty pointless too!!!

If you use a good quality battery, top quality cabling, alternator in good condition, you may be alright, unless your planning on competing!!!
Your system will only draw massive power, or reach anywhere near it a ratings, on a heavy drop, which isn't usually continuous - and your battery should handle that!!!

I'm only running a jl 13w7 on a 1000/1 amp at the mo, with a smaller jl amp for the fronts - recent standard alt, 0 gauge cabling, decent Bosch battery and no Probs at all!!!

Good equipment choice can help too - I used to use a lot of the old Orion hcca high current amps - and they can cause probs because they really do draw massive current when driven hard, (they eat fuses and split chargers for breakfast!!!), but other amps are a lot easier to power!!!

What amps are you planning to use???

[MattMcGrathE30]

Ive got an Orion HCCA-D5000 amp for the 15.2 subwoofer, Orion 250G5 amp for front speakers and an optima yellow top YTS5.5. Not got round to front speakers yet, not sure what would fit because its quite tight. All seems a bit much on the 90A alternator. I had 2 JL Audio 12W6 running 600RMS between them in my Peugeot 106 (lol) on a 65A alternator, and that was enough to dim the lights, at 800RMS they just didn't work they would just cut out. So i is the extra 25A really enough to handle nearly 4X as much power? I could understand that Peugeot alternators probably put out less than 65A, and that BMW probably put out more than 90A blah blah blah, but seriously would it be enough? I haven't got it wired up yet as i wanted to get some 'expert' advice first

[miniblob]

Was the pug on a standard battery???
I believe the battery makes a much bigger difference than the alt - unless you are playing loud continuous bass for a long period - i.e. test/competition tones!!!

I would def get this all installed first, have a play and see what happens!!!
I believe this amp goes into protect if your battery drops to 10v so you wont do it any harm!!!

Best place for more advice on the alt would prob be some of the clever guys on the talkaudio forum - I'm sure I heard of a few places on there that can rebuild an alternator to a much higher spec/output - obviously keeping installation simple!!!
It all comes at a price, but no point having expensive amps, etc and a cheap alternator letting you down!!!