Alternator Swap - BMW Forum

BImmerN2B · 02-13-2005, 09:31 AM

has anybody done an alternator swap? I have a 318i and I want to change the stock alternator to the 140 amp alternator. Question is, would it fit in the same space as the 80 amper and would I have to change anything like the gauge of the wire that comes out of it?

Speedy-325is · 02-13-2005, 12:33 PM

should fit just fine.....maybe have to change the belt, but the shop you buy the alt. from will be able to tell you.

I hope you are buying a BOSCH......

have fun.

Mark

drz · 02-13-2005, 01:11 PM

Yep, Direct fit. Hadn't thought of it, but now that Mark said it, make sure you ask about that belt.

drz · 02-13-2005, 01:12 PM

What will you be running that warrants an alternator upgrade?

BImmerN2B · 02-13-2005, 05:39 PM

I got a sub box in my vehicle. it got 2 12" subs and they suck. I want to upgrade the subs and the amp. Also I am planning to change my head unit for a in dash monitor and the speakers in the vehicle to be upgraded (not much wattage though). I also plan to get in the future an HID conversion. I am no electric guru, but I am not sure if the 80 amper that my car comes with can handle that. I will also buy an optima deep cycle battery (yellow top)

Rookie · 02-13-2005, 07:27 PM

It doesn't take alot to over power the cars alternator on these e36s. I am running two momo 10s about 500watts (birthmarked and certified) each at two ohms, and even at reasonable volumes I get light dim. As well I have a voltage readout on my radar detector and if I turn it up the system will run at about 11 volts, instead of its usual 13.2volts. It is almost embarrising at night to have my lights dimming all over the place. Let me know how the swap goes and what a good 140amp alternator costs.

dclaw · 02-14-2005, 04:48 AM

funny, I never had any real light dim with 2 JL Audio 12w6's running 400watts a piece rms on a kenwood amp in my 96 318i.

I mean, the only time I ever noticed was when the dome light was on, otherwise, I never noticed any other lights dimming, my voltage never dropped below 12.3 except on deep bass hits, which occasionally would drop it to 11.9 and also, compared to my friend's vehicles, with headlights dimming, lights in gauge cluster, dome lights really getting dimmer, my 318 literally had a reputation of having a super alternator or something....

maybe I just had one of the few wonderful ones? lol