new alternator will it help

[silverado13]

just a follow up, 200 amp alternator worked like a dream, im going to be doing the big 3 upgrade soon anyways

 

[Yeti_Owner]

I've got ask this...

When you need a 200Amp alternator, what kind of drag does it produce, versus just running the clutched belt-driven fan?

 

[great white]

Field doesn't load up until you call for the amperage and even then its only proportional to the amount of load...

 

[Jesse82nc]

I've got ask this...

When you need a 200Amp alternator, what kind of drag does it produce, versus just running the clutched belt-driven fan?

IMO from my engineering degree, I wouldn't think a 100, 200, or 300 amp alternator should not produce any different amount of drag. The way it produces more power is with more wire wound around it. The magnets don't actually touch anything when they spin so drag is not relevant. I could be way off here. Plus the alternator only actually outputs as much power as you are using. The rating is just what the maximum output is.

Via tapatalk on my Galaxy Tab 2

 

[Yeti_Owner]

IMO from my engineering degree, I wouldn't think a 100, 200, or 300 amp alternator should not produce any different amount of drag. The way it produces more power is with more wire wound around it. The magnets don't actually touch anything when they spin so drag is not relevant. I could be way off here. Plus the alternator only actually outputs as much power as you are using. The rating is just what the maximum output is.

Via tapatalk on my Galaxy Tab 2

Hmm. I would of thought the increased amperage production (when it's needed) would have caused a stronger field=more drag. In fact, I'm almost certain it does, or you wouldn't have 110 generators with different size engines, nor would they "lug" when you increase the load on them. Are you sure? What kind of engineering degree do you have? 0_o

 

[Yeti_Owner]

Found the formula. A 200Amp alternator pulling full load (I doubt it would ever do that, unless it was feeding an electrical fire) works out like this:
200Ax14.9V=2980W
745.7W=1HP
2980/745.7=3.99+15%(efficiency loss/heat)=4.59HP max load.

Now if you know how many amps your truck pulls at idle and on the highway, we can calculate what the real world numbers are.

 

[Jesse82nc]

Hmm. I would of thought the increased amperage production (when it's needed) would have caused a stronger field=more drag. In fact, I'm almost certain it does, or you wouldn't have 110 generators with different size engines, nor would they "lug" when you increase the load on them. Are you sure? What kind of engineering degree do you have? 0_o

It's a network engineering degree with a focus on electrical engineering. The magnetic field shouldn't change as alternators use permanent magnets not electromagnets. Although one could say an alternator is just a reverse electromagnet. It's hard to say without doing a test, I can't say when I was in school 10 years ago that we ever talked about drag from magnets in a generator much. But I do know you can easily run a 300 amp alternator on a small civic without issue. So I don't think it takes more power to run a larger alternator. Someone needs to do a test on a dyno maybe.

Via tapatalk on my Galaxy Tab 2

 

[Yeti_Owner]

It's a network engineering degree with a focus on electrical engineering. The magnetic field shouldn't change as alternators use permanent magnets not electromagnets. Although one could say an alternator is just a reverse electromagnet. It's hard to say without doing a test, I can't say when I was in school 10 years ago that we ever talked about drag from magnets in a generator much. But I do know you can easily run a 300 amp alternator on a small civic without issue. So I don't think it takes more power to run a larger alternator. Someone needs to do a test on a dyno maybe.

Via tapatalk on my Galaxy Tab 2

Ya, the electromagnet is the winding on the armature, the hysterisis on it "self-energizes" on generators, on alternators, I believe it "primes" from the battery. Maybe I've got that backwards. It's been a while.

 

[Jesse82nc]

Found the formula. A 200Amp alternator pulling full load (I doubt it would ever do that, unless it was feeding an electrical fire) works out like this:
200Ax14.9V=2980W
745.7W=1HP
2980/745.7=3.99+15%(efficiency loss/heat)=4.59HP max load.

Now if you know how many amps your truck pulls at idle and on the highway, we can calculate what the real world numbers are.

Either way, going back to the original question, the 30 amp for the e-fans would equate to the alternator using an extra 1/2 hp. I would think it takes a lot more than that to run the mechanical fan.

Via tapatalk on my Galaxy Tab 2

 

[Yeti_Owner]

Either way, going back to the original question, the 30 amp for the e-fans would equate to the alternator using an extra 1/2 hp. I would think it takes a lot more than that to run the mechanical fan.

Via tapatalk on my Galaxy Tab 2

Maybe..

When it's got a good clutch, it pretty much free wheels at higher rpm, unless the temp is high enough to warrant the viscous coupling spinning it harder. Idle is a different matter, but people don't normally care about that lol.