M998 Generator Q: Can a 450 amp be used in a M998 or is 200 amp the only upgrade available?

[FlameRed]

Another newbie question. I tried searching but I am not finding the answer.

I am eventually looking to upgrade the stock M998 generator because I am installing an electric winch.

Seems like the price of the NOS 450 amp generators are much less than beatup "used" 200 amp generators that are untested. Can a 450 amp be installed in a M998?

I see kits are needed to mount the 200 amp in the M998. I but would these upgrade kits work for a 450 amp? Or is there a different kit for the 450 amp?

Thanks in advance!

 

[TOBASH]

From my conversations with Steve, Retired War Horses doesn't like the 400 amp units. Overly large and such.

 

[NDT]

Agree the 400s are HUUUGE and heavy and rub against things.

 

[Coug]

How big of a winch are you planning to install?

Most winches rely on battery capacity, not the alternator/generator.

And for comparison, a 12V 12k winch can draw around 350-400 amps.
The same winch as a 24V unit will draw half of that, or 170-200 amps.

There is no reason why you would need a larger generator in order to run a winch. You can't run an electric winch constantly anyway, so there isn't any real reason to need anything larger.

An early truck with the 60 amp generator will still handle a winch just fine. As long as you are running a good set of batteries, and aren't in such a hurry that you end up burning up the winch, then you should be just fine.

My recommendation if you truly plan to use the winch a lot is spend the extra money to buy the 6TAGM batteries and a good battery equalizer to maintain them, rather than spending a whole lot more money than that on the 200 amp system.

Another option is a civilian type alternator with a battery balancer. Delco has multiple 24V alternators. For $3-400 you can buy a 110amp alternator and almost double the current output, or for around a thousand you can get one at 160 amps. There are other options out there as well, but Delco makes good stuff and is repairable. It takes a little modification of brackets, and probably finding the right pulley to match to your system, but others have done it (usually the 70 amp version)

 

[TNDRIVER]

Another newbie question. I tried searching but I am not finding the answer.

I am eventually looking to upgrade the stock M998 generator because I am installing an electric winch.

Seems like the price of the NOS 450 amp generators are much less than beatup "used" 200 amp generators that are untested. Can a 450 amp be installed in a M998?

I see kits are needed to mount the 200 amp in the M998. I but would these upgrade kits work for a 450 amp? Or is there a different kit for the 450 amp?

Thanks in advance!

If you plan on putting a top quality electric winch $$$$$ in your truck IMHO the mile marker winches are the way to go. Don"t let the hydraulic thing scare you. Even a cheap winch that requires a generator and battery swap deserves to be priced out, you might be surprised. My two cents. A J

 

[juanprado]

400 amp uses their own set of brackets different than the 200. As stated very heavy (like you are not going to install it by your self with out an overhead winch) and makes the engine compartment very tight. Epay sometimes has the 400 amp brackets.

Make sure you are looking at the correct niehoff unit as 450 could be an mrap unit or a non hmmwv application. A few different very high amp niehoff units out there.

 

[TOBASH]

If I were you I would strongly consider avoiding the 400 amp alternator.

Not only will you need to replace the alternator, you will need to replace the brackets and an important portion of the wiring harness. If you do not replace that portion of the wiring harness you will burn out your protective control box/EESS.

The 400 amp alternators are cumbersome because they are tremendously oversized. This causes vibration problems and overheating problems and other significant issues under the hood according to Retired War Horses.

I ran a winch with a 60 amp alternator without issues. You need good batteries and not a powerful alternator.

 

[MarkM]

These are rough numbers but good for this discussion.

A 12V 100A alternator uses about 4HP so from that.

100A Alt @24v=2400W

200A Alt@24v=5800W

400A Alt@24v=9600W

A 24v Alt requires 8hp for every 100A.

That big 400A Alt will suck up 36HP to run under full load.

A 400A Alt will put a hell of a lot of drag on our old anemic Detroits.

If I remember correctly our clutch fan uses about 23HP and we all know what that feels like.

Mark

 

[Coug]

These are rough numbers but good for this discussion.

A 12V 100A alternator uses about 4HP so from that.

100A Alt @24v=2400W

200A Alt@24v=5800W

400A Alt@24v=9600W

A 24v Alt requires 8hp for every 100A.

That big 400A Alt will suck up 36HP to run under full load.

A 400A Alt will put a hell of a lot of drag on our old anemic Detroits.

If I remember correctly our clutch fan uses about 23HP and we all know what that feels like.

Mark

I thought the fan was around 10hp, but that's still quite a bit when you're starting out at 150/160/190hp.

Typically in the real world I've found for gasoline powered generators, it's 1kw per 2 hp. With diesels it's a little less, but I would expect the 400 amp to use around 20hp under full load. You're almost never going to be under that much load though, unless you have an inverter hooked up or some 24V load like an air compressor or something like that. Ad far as I know the 400 amp units were only in special applications like the contact maintenance truck (5kw inverter and air compressor built in) or maybe some of the radio type trucks.

There is still a heavy spinning mass inside the generator, even if you aren't using much draw. That means every time you accelerate the motor, it's spinning up that mass. I'd assume the 400 amp units have the clutched pulley and can spin faster than the belt freely, otherwise you're talking a lot of belt stress with every change of speed. I know my 200 amp likes to chirp the serpentine belt whenever I let off the throttle too fast.
Either way, it's a big loss of power during acceleration for very little gain. Unless you're running multiple electric winches all at the same time it's massive overkill.

 

[Crapgame]

My 1986 M1026 I was signed for on active duty had the Warn electric winch and 60amp alternator, never had any problems.

 

[frauhansen]

Another newbie question. I tried searching but I am not finding the answer.

I am eventually looking to upgrade the stock M998 generator because I am installing an electric winch.

I suspect an misconception.
You feed your winch out of the batterys, not out of the generator. Your battery can not be charged faster with a bigger generator.

A 24v Alt requires 8hp for every 100A.

That big 400A Alt will suck up 36HP to run under full load.

Not right in every case... but wrong in 99.21% of all cases. What you describe is the maximum energy that the alternator need at full electrical load.
You can turn every car-alternator with your little finger.... until you partially short circuit it... with a consumer.

 

[Retiredwarhorses]

The short answer is yes, you can install a 400amp into an M998 with a 6.2, had one here at the shop…would I? No…it’s darn near the size of the engine, but folks do what folks do.