Alternator Upgrade Suggestions?

I have a 2009 Tahoe LT with a stock alternator.
I am building this vehicle for overlanding and it will/does have accessories such as lights, a winch, etc..
I am considering to move up to a heavier duty alternator to handle the extra load.
Does GM produce a heavier duty alt, or will I have to look at aftermarket?

What suggestions do you have?

Lots of guys here run the Mechman alternators as an upgrade. Pricey but good.

mechman, they custom build each one so it usually takes about 4 weeks to get one so I wouldn't stay on the fence for too long, website shows they are 2-3 weeks but it can take longer
there are options
1. standard pulley setup with 320amp output (no rev limit)
2. reduced pulley size and higher output at idle up to 400amp (rev's limited to 5k for sustained period)
3. custom colors
the latter is probably fine in most cases but I personally erred on the side of caution and went with the 320amp model: 8302320

you can order custom colors but that just cost more...they are already a bit pricey


I would stray away from the generic ones stating high output, they tend to fail in short order, just word to the wise ya you might save a few bucks initially but it's not worth it.

also you can get up to about a 260amp oem if you poke around and do some research the k2xx 2500's have a option for 1 you just have to be sure the pulley is correct as they make a standard pulley and clutch pulley, the clutch pulley will not work but the standard one will other than that fitment is the same from 2005 to 2020, maybe even up 23 I haven't researched the t2's yet.

Doubeleive said:

mechman, they custom build each one so it usually takes about 4 weeks to get one so I wouldn't stay on the fence for too long, website shows they are 2-3 weeks but it can take longer
there are options
1. standard pulley setup with 320amp output (no rev limit)
2. reduced pulley size and higher output at idle up to 400amp (rev's limited to 5k for sustained period)
3. custom colors
the latter is probably fine in most cases but I personally erred on the side of caution and went with the 320amp model: 8302320

you can order custom colors but that just cost more...they are already a bit pricey

Alternators - Chevrolet - Suburban - All Gas Engines (No 7.4L) - 2005 - 2013 - Mechman Alternators

www.mechman.com

I would stray away from the generic ones stating high output, they tend to fail in short order, just word to the wise ya you might save a few bucks initially but it's not worth it.

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Thanks, that helps!

On that page for my model, I only see one that has a standard pulley and is only at 250 A.

That model number you gave is saying only 320 A. Just wondering if we are on the same page?
If so, where did you find the shorter belt required for the smaller pulley?
Also, any issues with the ECU when using this alt?

gmartin1215 said:

Thanks, that helps!

On that page for my model, I only see one that has a standard pulley and is only at 250 A.

That model number you gave is saying only 320 A. Just wondering if we are on the same page?
If so, where did you find the shorter belt required for the smaller pulley?
Also, any issues with the ECU when using this alt?

Click to expand...

note in the photo below FITS ALL GAS ENGINES 05-13, model number is circled as well
the pulley is standard size

and no, no issue's with anything. I would also upgrade the alternator to battery cable to a good quality cable

and just to clarify the only difference between 00-2020 ALL GAS ENGINES is the older 00-04 used a 4 pin connector (non-digital), the 05 and up use a 2 pin (digital)
the 15-20 fitment is the same the only difference is some use a clutch pulley and some do not.
autozone, parts dealer, etc, etc will never tell you that info. you can take one out a 20 and put it in a 05 or any other year make model GAS engine any size
i just wouldn't slap a 105 amp in a vehicle that needs more.......usually the amperage is shown somewhere in the part number on the alternator if you are poking around the junkyard like 80160kl (160) is the amperage, versus 40105llj (105) is the amperage and smaller amperage usually have the small case and are visually smaller looking but will bolt up the same

Doubeleive said:

also you can get up to about a 260amp oem if you poke around and do some research the k2xx 2500's have a option for 1 you just have to be sure the pulley is correct as they make a standard pulley and clutch pulley, the clutch pulley will not work but the standard one will other than that fitment is the same from 2005 to 2020, maybe even up 23 I haven't researched the t2's yet.

Click to expand...

this what I would do, oem and easily sourced parts. I've seen a few pics and threads on the corvette boards of the mechman failing and long wait times for replacements. not a big deal when your corvette sits in the garage most of the time and they do look nice all billet and powered coated. not great when you're away from home. I do road trips so have stayed with a oem and lessened the load with by changing to pwm brushless fan and things like that.


as said above, definitely make sure your alt wire can handle the extra current. my old 96 I put the larger case diesel alt on it after going electric fans. charged great but the alt wire was warm to the touch. had to step up wiring gauge.


ict makes a very nice atl spacer if you ever need to run a larger case alt in the stock bracket. all things being equal, larger case the larger the rotor and stuff, more efficient and cool better than getting the same power out of a smaller package.

just info I've found looking around at alternators.

I did a similar setup for overlanding and went with the higher output OE fit from carquest. There was 145 and 160 Amp option. I put in the 160 with a second battery in parallel and haven't had one issue. 2008 yukon denali.

I would assume that you are going with LED lights, maybe a 12v fridge, etc. In my opinion it's not necessary to have 320 amps available - unless you plan on incandescent bulbs, continued winch use, etc. Basically if you have reserve battery capacity you can conquer a lot of tasks. Throw in a solar panel for stationary use and you should be fine. There's only so much you can fit in a tahoe......they fill up quickly when packing for overlanding.