Unbelting The Alternator

[green swift]

Some guys on this site have unbelted the alternator like Darin MPG to gain that extra 10% . I have seen belt issues from this idea...Its a great idea but the overall belt issue stops me from doing the mod. So am throwing this out to the forum, How about using a second alternator in its place. Just plug all wiring into the second alternator and leave the oem in its place... No belt issue???? My other issue is heat in the other alternator??? Anyone have any ideas????

[DracoFelis]

Either you are confused or I am. You say there are "belting issues" with disconnecting the alternator, than you talk about using a 2nd alternator to get the benefit. Just what are you asking/suggesting?

When you mentioned "belting issues" with disconnecting an alternator, I at first thought you were talking about issues with disconnecting a multi-use "serpentine belt" from the alternator drive (as some cars do use "serpentine belts" for this purpose, whereas others give the alternator its own belt). However, if "serpentine belts" were the primary issue, then the solution is to either leave the belt on the alternator but disconnect the electrical wires (thereby lowering the load to just the static losses to freely spin the alternator), or replace your "serpentine belt" with a shorter one that doesn't go via the alternator drive shaft.

But that can't be what you are talking about, as you then go on to suggest that you hook up a 2nd alternator, and wire the car to it. However, I can't tell what you expect to accomplish with a 2nd alternator, that you can't accomplish at least as well with the car's stock alternator! Because either way, if you are generating electricity with an alternator, it is going to put drag on the engine, and therefore lower your FE.

The thing is, the FE gains you get from disconnecting your alternator (via the belt, or even just via the attached electrical wires) comes at a "price". And that price is, you have to supply the car's electricity needs by some other means (for example, larger batteries you plug in and recharge at home). Which FWIW is the primary reason I haven't done this (more "extreme") mod to my car yet.

Simply put, disconnecting an alternator is just the most complete/extreme example of lowering the electricity generating drag on the engine (in this case lowering it to 0, by disconnecting that source of the drag). But to do that, you have to supply 100% of the electrical needs of the car by some means that doesn't put drag on the engine (i.e. another alternator is out, as it would just move the drag from one device to another, not eliminate the drag on the engine). And if you can't do this 100% of electricity by another means, you (IMHO) shouldn't be doing an alternator disconnect.

OTOH keep in mind that even without an alternator disconnect, you can get part of the FE benefits (that a full alternator disconnect would give) simply by using less electricity in your car (as less electrical generation, even with a stock alternator, lowers the alternator drag on the engine). And saving electricity (in the car) is something I have done a lot (with good results for FE). For example, I have converted a lot of my car lights to energy effect LED lighting (saves a LOT of power when the lights are on), I only use my lights when I really think they are needed (avoids wasted energy during the day), I frequently only run my fans when I need them (blower fans are heavy users of electricity), and I even have a variable temp radiator fan control (so I can set my radiator fans to come on at a hotter temp then stock). And all these power savings add up.

But even I haven't yet taken the next step of fully disconnecting the alternator, to save even more alternator drag on the engine. I know some GS members have, and I commend them for it, but (at least so far) I find the effort to "safely" disconnect my alternator (given my long commutes, and therefore my higher than average need to store/supply electricity during those commutes) to be more trouble than it's worth. So, instead I just go with the lessor (but still significant) gains that can be had simply by conserving electricity, but leaving the alternator hooked up. In that way, I get some improvements in FE, but I still always have the alternator as a "backup" to supply my car's electrical needs (yes, at some fuel costs, but still the alternator is there when needed).

[green swift]

Originally Posted by DracoFelis

Either you are confused or I am. You say there are "belting issues" with disconnecting the alternator, than you talk about using a 2nd alternator to get the benefit. Just what are you asking/suggesting?

When you mentioned "belting issues" with disconnecting an alternator, I at first thought you were talking about issues with disconnecting a multi-use "serpentine belt" from the alternator drive (as some cars do use "serpentine belts" for this purpose, whereas others give the alternator its own belt). However, if "serpentine belts" were the primary issue, then the solution is to either leave the belt on the alternator but disconnect the electrical wires (thereby lowering the load to just the static losses to freely spin the alternator), or replace your "serpentine belt" with a shorter one that doesn't go via the alternator drive shaft.

But that can't be what you are talking about, as you then go on to suggest that you hook up a 2nd alternator, and wire the car to it. However, I can't tell what you expect to accomplish with a 2nd alternator, that you can't accomplish at least as well with the car's stock alternator! Because either way, if you are generating electricity with an alternator, it is going to put drag on the engine, and therefore lower your FE.

The thing is, the FE gains you get from disconnecting your alternator (via the belt, or even just via the attached electrical wires) comes at a "price". And that price is, you have to supply the car's electricity needs by some other means (for example, larger batteries you plug in and recharge at home). Which FWIW is the primary reason I haven't done this (more "extreme") mod to my car yet.

Simply put, disconnecting an alternator is just the most complete/extreme example of lowering the electricity generating drag on the engine (in this case lowering it to 0, by disconnecting that source of the drag). But to do that, you have to supply 100% of the electrical needs of the car by some means that doesn't put drag on the engine (i.e. another alternator is out, as it would just move the drag from one device to another, not eliminate the drag on the engine). And if you can't do this 100% of electricity by another means, you (IMHO) shouldn't be doing an alternator disconnect.

OTOH keep in mind that even without an alternator disconnect, you can get part of the FE benefits (that a full alternator disconnect would give) simply by using less electricity in your car (as less electrical generation, even with a stock alternator, lowers the alternator drag on the engine). And saving electricity (in the car) is something I have done a lot (with good results for FE). For example, I have converted a lot of my car lights to energy effect LED lighting (saves a LOT of power when the lights are on), I only use my lights when I really think they are needed (avoids wasted energy during the day), I frequently only run my fans when I need them (blower fans are heavy users of electricity), and I even have a variable temp radiator fan control (so I can set my radiator fans to come on at a hotter temp then stock). And all these power savings add up.

But even I haven't yet taken the next step of fully disconnecting the alternator, to save even more alternator drag on the engine. I know some GS members have, and I commend them for it, but (at least so far) I find the effort to "safely" disconnect my alternator (given my long commutes, and therefore my higher than average need to store/supply electricity during those commutes) to be more trouble than it's worth. So, instead I just go with the lessor (but still significant) gains that can be had simply by conserving electricity, but leaving the alternator hooked up. In that way, I get some improvements in FE, but I still always have the alternator as a "backup" to supply my car's electrical needs (yes, at some fuel costs, but still the alternator is there when needed).

What I meant is that my drive belt is driven off the crank right that interns drives my water pump and alternator all in one go. I have check into a shorter belt there is nothing that short that works for my 1.3L swift. I also meant using the second alternator as a electrical connection only no drive belt...
No belt no engine load... You cannot just disconnect the alternator wires or the car dies... Also, I was just seeing if anybody has thought off this idea to see the all around problems with it.

[GasSavers_JoeBob]

Seems to me that one could fabricate an idler pulley to replace the alternator. Then just remove the alternator and isolate the connections so the alternator can be re-installed when you get tired of charging your battery every day and depending on the kindness of strangers to jump-start you when the battery gets too low.

A piece of heavy sheet metal or metal plate which could be bolted in place of the alternator, a bearing to which could be attached to the bracket and to a pulley off a junk alternator (if the Swift uses the same 3-rib pulley that the Metro uses) is what comes to mind if I were to be of a mind to try such a thing as going w/o my alternator.

This would allow you to use the same belt, and keep your water pump working the way it should.

[lowbridescape]

If I may offer a thought.

I think the issue is what powers the second alternator.

If you use parasitic power supply like a RAT (Ram Air Turbine) as are used in some aircraft applications, a) they only work while you're moving (and it would take a BIG turbine to produce much power at 40-60 mph) and, b) they create drag, which the engine must overcome by producing more power. The direct drive belt drive would almost certainly be more efficient.

If the second alternator is a gasoline/propane/diesel/alcohol/(whatever) powered alternator, then you should rightfully have to account for the fuel consumption of that alternator along with what goes through the motive engine. And you'll probably find that the those little portable generators are not very efficient. But on second thought, the poor efficiency of the little engine may be offset by the ability to cycle it. It would run at full power, charge the battery and shut down. It may be tough on batteries, though.

Uh-oh...now ya got me going. And I'm going off on a tangent.

Battery. Have a second battery for car loads besides starting. Lead acid battery starts engine, gets recharged, then disconnected from the charging system. Second battery is a 12-13.5V battery pack built up of Li-ion D cell batteries. (I seem to recall the original Escape Hybrid used 250 D cell batteries to produce a 330V battery pack). It provides more stable power between charges.

Put the alternator on an air conditioning compressor clutch (because I don't think they make alternator clutches). Advantages: 1) don't even have to carry the load of the freewheeling alternator if it's not charging. 2) larger pulley turns alternator more slowly. This may eliminate charging at idle speeds, but reduces energy spent turning alternator way faster than is needed most of the time.

Then as others have discussed in related threads, tie clutch to brake peddle. Charging when the engine is braking provides regenerative braking. Free power. Otherwise, it engages based on battery pack voltage.

[suspendedhatch]

Disconnecting the alternator is now the newest worst idea I have ever heard.

You'll have weaker spark and you'll also force the ECU to run rich because injectors do not fire as well with low voltage.

Cycling the battery like that wears it out and any small increase in FE will be offset by the cost of replacing the battery.

Not to mention that on a modern car the alternator provides power on demand. In other words, it only produces as much drag on your engine as is necessary to provide power for the accessories you're running, run the engine, and keep the battery charged. Turn off all your accessories and it barely produces any drag.

When I say "modern car" I can only speak confidently about any fuel injected Honda/Acura. I have been surprised time and again at how far behind domestic vehicles are in technology.

[GasSavers_RoadWarrior]

Chryslers have had it since mid-late 80s, Fords have had it with EEC-III and up I think. GM might have lagged a bit, since I hear of homebrew power ppl wanting GM alternators, because there's no separate field hookup or something, I figure they got there by OBD-II time though.