High-amp Alternator Upgrade on E30?

[e30davie]

yer do the math properly, 1200w amplifier means nothing. At normal listneing levels its probably drawing less current than a headlight.

ECU, EDIS, electric windows are largely irelevant. and unless cars that were optioned with heated seats had a larger alternator I would say thats irrelevant too.

in saying that 65amp is a little on the small size. an m20 alternator is 80amp apparently. can you fit one of them?

if i was going down the alternate alternator (hehe) id find an old dumb one that is internally regulated. wiring is very simple. main power and the exciter bulb and thats it. anything modern is going to be too complicated with complex pwm control or simliar.

[roguetoaster]

I think you might want to check your calculations on needed amperage and safety limits. Seems like 200A+ is very high, but I didn't do the math.

That said, if the alternator doesn't have a simple voltage regulator you will probably struggle to control it.

[hozzziii]

Hi
I have an '85 316 and I'm going for a 2 liter turbo project.
The factory alternator on my car is a 65amp Bosch. I think it was 80A on 318i maybe. I've also noticed this alternator looks very much like the one used on the M20.
The thing is, I already have a 1200w amp and stereo on the car, and I'm also going to be getting a standalone ECU, EDIS, heated seats, electric windows etc. and right now I'm worried the current alt is not going to cut it.

So I went on qualitypowerauto(dot)com and put the numbers in, and it said I need 224 amps to be sure.
Then I thought ok I'm not gonna buy a custom alt for $400-600, so I thought ok let's look what BMW puts in their cars, let's see if I can find something used for a better price.

The closest one I found was on the N20 engine used in 328, 428, 528 cars which is rated for 210amps.
Mounting seems a bit tricky but I think I can manage with maybe some custom brackets and such.
My problem is BMW at some point started using this IBS or BSD system or whatever, for changing voltage and checking battery charge and a lot of stuff that I don't know.

So on this particular alt there's another connection:

That I don't know what to do with.
So I asked on Bimmerfest in the F10 section, they said that's for the IBS, then I asked well do I leave it? do I connect it to something? Someone said it's probably not going to work.

So, I'm not sure what to do right now.
I want a high-output alt to be safe, this was the closest I could find for an affordable price.

I know some members have swapped a 140 amp on their M20s, I think it would be low for my particular project.
So what do you think?
How can I fit an alt that can output north of 200amps that works fine on E30?
Any advice would be very appreciated, thanks.