high output alternator?

**kosta** · 03-22-2005, 09:15 AM

my 80 amp in my 318 isnt cutting it

what are my options for getting a high output alternator?

**imedina79** · 03-22-2005, 09:25 AM

I don't think you can, that serpentine belt has to fit just right. A larger alternator might not align correctly. Why not just get a stock sized alternator and then get an Optima yellow-top battery?

**kosta** · 03-22-2005, 09:40 AM

i have a yellow top a big one from a rig application

w/1600 watts of amps the alternator isnt cutting it

**imedina79** · 03-22-2005, 10:06 AM

Hmm... I do know this one guy that put an alternator from a 740 in his e36 325. I'm not sure how much wattage his system puts out but he says that the alternator fits, his lights don't dim, and he doesn't run any caps.

I'm subscribing to this thread now because I have a about 1000w running with 2 caps (1.5 farads), an alternator that's less than a year old, an Energizer battery that's about a year old, and my lights STILL flicker when I play music loud!

**wsmc831** · 03-22-2005, 10:10 AM

not sure if the 318 is any different, but I just bought and installed a newly rebuilt Bosch 140 amp. They came stock on some m3's, with heated seats I believe.

bolted right in, HUGE improvement in output. 80 amp and cap does nothing, if you don't have the output to keep up, the cap does no good. yes, I have a cap.

approx. 1300 watts rms. 140 still probably isn't enough, but for 140 delivered, plus not having to worry about replacing an alternator again for many years, it'll do just fine.

battery upgrade is next.

**kosta** · 03-22-2005, 10:16 AM

hmm
i guess i have to see one and compare the size to make sure the belt lines up

**wsmc831** · 03-22-2005, 10:18 AM

it will be obvious. and nearly everyone I've heard of that has done the swap has had 0 problems.

worst case is you need a new pulley to put on the alternator if it's too long...
but not sure if 318 is different or not, but I know if you have the standard valeo 80 or bosch 80, the 140 will bolt to the car fine, just the pulley that is in question.

**kosta** · 03-22-2005, 10:20 AM

i'll post a pic of mine tonight and maybe you can tell me how it compares to the bigger one

**wsmc831** · 03-22-2005, 10:21 AM

no problem, just put it in this thread and I'll get a notification. Just did the swap 2 weeks ago, so still pretty fresh.

easy swap by the way, just removed my airbox, no fan removal needed.

plus, my 80 is still sitting on the garage floor :-)

**eric77** · 03-22-2005, 10:30 AM

You might want to try pulling out the cap you have in. That coul dbe making the situation worse. Caps really are not a good additon when you have dimming. They simply pull more juice from the alternator putting an even greater strain on it. I say either get an h.o alternator or add an optima yellow top to the trunk.

**TWKTCC** · 03-22-2005, 12:25 PM

Before purchasing anything.
1. Remove the CAP
2. Run at least a 4ga ground wire (bigger is better) from the Neg bat terminal to a solid ground, short as possible. Make sure bat terminals have no corrosion.
3. Ensure your ground for the amps is %100 rock solid.
4. Put a "better" battery up front (if thats where your bat is) Yellowtop or the like.
5. Upgrade the charging wire size, run a wire from the charging post of the Alt. to the positive terminal of the bat. (4ga is a good size)
6. If above doesnt help add an auxillary battery.
7. Lastly upgrade your Alt. to a higher amp unit.
These steps will prevent you from spending unnecessary $$$.

Steps 2,4 & 5 are commonly called "the big three". A must for a high powered system.

**kosta** · 03-22-2005, 12:32 PM

my battery is in the rear, its brand new
its a huge yellow top but not for a car, its for a big rig the battery is huge

all wires are 4 gauge if not greater for ground

i'll try the alt upgrade and if i still need more, ill add a second battery under the hood

edit
i never said i had a cap

**JPWheelr** · 03-22-2005, 07:02 PM

the 140 amp alternator came on most automatics. M3's had the 110 or 80 amp, manuals = 80 amp.

Bosch fits with Bosch, Valeo with Valeo. Make sure you get the same voltage regulator as your stock one.

JPWheelr
80 amp (bosch) M3, with currently worthless 15 farad capacitor switching to 140 amp (bosch)

**kosta** · 03-22-2005, 08:31 PM

so i have to find a 140 amp valeo?

**JPWheelr** · 03-23-2005, 12:47 AM

If you have a valeo, yes. The pulleys/mounting - very different.

**kosta** · 03-23-2005, 08:47 AM

i just did a search and there's lots of info

seems lots of people have done a valeo to bosch swap
and they had to replace the pulley

seems easy enough by i just say conversions on m3's

has this been done to a 318?

**wsmc831** · 03-23-2005, 10:05 AM

Originally Posted by JPWheelr

the 140 amp alternator came on most automatics. M3's had the 110 or 80 amp, manuals = 80 amp.

Bosch fits with Bosch, Valeo with Valeo. Make sure you get the same voltage regulator as your stock one.

JPWheelr
80 amp (bosch) M3, with currently worthless 15 farad capacitor switching to 140 amp (bosch)

110 amp alternator? never existed. Either 140 bosch, or 80 amp bosch or valeo. 318's had some 70 amp models as well.

I switched from an 80 amp valeo to a 140 amp Bosch 2 weeks ago, pulleys were identical, bolted right up.

voltage regulator is on the alternator, not external.

**mole** · 03-23-2005, 08:24 PM

There is a 105 amp alternator listed on bimmerzone's parts catalog.

**carcrazed4life** · 03-23-2005, 10:53 PM

I know on e36 m3s, you can get the pulley with the alternator and change the belt, you are good. I have the Bosch 140amp. I also have the Stinger 1700 Amp battery. 0 Guage runs for all my stuff, and best of all, a 50 Farad cap. This is overkill when I ran 4 1000/1s on my 2 Crystal CMP x2 12"s (800 RMS a coil)

No dimming anything...

**5mall5nail5** · 03-24-2005, 11:41 AM

I too did the alternator swap. I had a 80A Valeo, maybe it was 140A, but it wasn't up to snuff. I retro'd the Bosch 180A, all you need to do is make sure you get a pulley made for the bosch, you can't swap your old pulley to new unit. Now with all my audio blaring and computers running i have no issues with capacitor

**johnny010** · 03-24-2005, 11:03 PM

no one mentioned the big 3 upgrade...

**FriedKalamari** · 03-24-2005, 11:45 PM

let us know how this goes, im interested in doing this to my 318 as well

**kosta** · 04-14-2005, 09:40 AM

i didnt want to go the trial and error route so i got a stinger 200amp
its coming today

it was expensive but it will save me the headaches

**5mall5nail5** · 04-14-2005, 09:52 AM

Originally Posted by kosta

i didnt want to go the trial and error route so i got a stinger 200amp
its coming today

it was expensive but it will save me the headaches

i just looked up prices... did you really pay $1000 for an alternator?

**kosta** · 04-14-2005, 09:55 AM

i pd wholesale for it
$613 i think it was + shipping

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