I'm looking to put a secondary alternator on my 1995 Pontiac Bonneville 3800 Series II motor. I'm running 4-12" subs and a 3000 watt amp. I need to figure out where i can mount the secondary alternator and what brackets i can use or if i need to make new ones. Any help is greatly appreciated.

Thinking about this, I can't come up with any logical places.

Dead center on top, the intake is in the way.
Alt has the top back blocked
Below that is the ps
Up front is the coils and ac

i have a new 140 amp alternator from a supercharged 3800 motor and it does an ok job, better than the 124 from 1995 that was in there. I have a battery in the factory underhood location and 4 optima yellow tops in the trunk, but the battery needle still moves, even when i'm crankin down the highway. And you are right, there really is no room, unless i do something wild with brackets, but even than i run the risk of bending the bracket from the torque of the motor. Once i do get the secondary alternator in, it'll be strictly for the system. i'm looking into an alternator from an 04 Escalade. I found a high output 250amp alternator that'll fit the 6.0liter motor that i could make fit once i find out where to put the brackets. but i still need to find that sweet spot, even if i had to use another 140 amper like the one i have now, that would still be better than just one

How about..


Relocate the coils/bracket to the rad support (keeping the ICM ground at the head though), bolt the bottom alternator leg to the front head, modify the steel bracket that runs from the alt to the coil bracket so that it runs from the stock alt to the new alt, then you just have to figure out one more mount.

Belt wrap wouldn't be that great but it'* nothing some washers and and an idler pulley somewhere wouldn't fix.

Several manufacturers make 200 amp altenators to fit the 3800. I would think that enough to keep up considering your 4 yellow tops, unless your bumping down the road maxxed out full time . Are you using a capacitor as well? Alot of people think extra batteries are better than a capacitor, the custom shop that did most the work on my car feels both are needed. Did you change out the charging wire?. It should be 4 gauge, Adding amperage wont do anything if the wire to the battery/ies is choking the current.

I'm running the power wire (Kicker Hyperflex 0 gauge) directly from the alternator back to my yellow top batteries. I hate capacitors, every person i know, professionally installed or not, has had their capacitor die on them. I hooked up 2-5 farad caps in my buddy'* tiburon, each cap on a 800 rms kenwood amp feeding a 12" L5 a piece, one cap died, the other is on it'* way. And i'm running my amp full tilt every time i have my system going, no sense in not using the bump right? My 140 amper i have right now works decently, needle still moves on the gauge slightly, but i want to be able to leave the needle at 14.4 volts or better consistently. My amp is very tempermental when it comes to power consumption. It needs 14 or better to beat to it'* fullest extent. I'm calling up my alternator company at my store to see if i can spin an alternator in reverse and still get power, i figure i can extend mounting points off the strut tower and off the block and leave the pulley in the belt configuration as it is now, but that'* only if it'll work. Other wise i'm thinking of moving the coils, but i'm still open for ideas, keep 'em comin!

I use the 0 gauge hyper flex throughout my entire system, linking the alt to the batteries, between all the batteries, from the batteries to the amp, and all grounding points. I have to up the big 3 still but that'll come when i figure out my alternator situation.

yellowtops arn't that great for what you are using them for fwiw. you're better off with larger kinetics batteries. sell the yellows asap and buy those. if you want anything from optima a redtop under the engine bay would be best.

caps are worthless. i'm glad you're not a fan of them.

just get a 200amp alt. you'll be fine with 2 or 3 good sized kinetics batteries. multiple alts isn't needed for what you are drawing not really needed at all..

oh and you can still do the Big 3 before you decide on what your going to do. the big 3 will SERIOUSLY help your voltage stabilization.


oh and if i were you ui'd use a XXX, BTL, DD, or Stroker instead of those kickers. a ton more SPL which is obviously what you are looking for. just an idea...i'd seriously check em out

The yellow tops work great for what I'm doing, i need the extra reserve and drainage capacities because i have other things drawing power as well. Yes, a kinetik would help the system since they are specifically designed for high draw systems, but when you are like me, you go big or go home. I'm partial to Optimas because i know they are reliable and i get them super cheap through my place of work. If i had the money, I'd actually be getting a few Powermaster D3100 cells. Also, I'm not running kicker subwoofers. The post is written as Kicker Hyperflex 0 ga. power/ground wire. I had kickers before and i blew them up, far to temperamental about power handling. Also, their break-in period is ridiculous, again far too temperamental. I'm running 4-12" Torrent Audio Mistrals. They were designed by Audiopulse and they pound hard with 130 oz magnets. I've been looking into some Fi BTLs or maybe an RE MT. But as for the alternator, a dual alternator setup will give me the ability to keep my factory alternator for the motor only. Being a 95 with 226,000 (turning 227 in a couple days), i need to baby the motor till i can get the overhaul taken care of. Yes a second alternator will rob the motor of power and strain it more, but once I get the motor rebuilt, that dual alternator setup will be amazingly powerful True, a 200 amp alternator would suffice for my power needs, but why not make it look nasty with dual alternators, it may not be the easiest route, but I'm going for ability.

Definitely the easiest thing to do is clock the coil bracket forward on it'* forward bolt, and bolt up another alt to the head where the top coil bracket bolt was. Then, connect the two alts together with a strip of decent size sheet metal, and connect the alt to the clocked coil bracket.

It would kind of be like this but instead of that weird looking thing with the big pulley, there would be an alt:
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