Alternator Delete

[Duffman]

This is getting out there guys, either take the alternator off the car a rig a battery charger up to the car so you can charge everytime you stop or put a relay in between the alternator charge terminal and bat + terminal that closes when you are off the gas or on the brake.

[JohnnyGrey]

Not worth it at all. Remember that your transmission taxes the power that goes through it. You're better off getting it right off the crank than losing 20% it through the trans.

Instead look into an underdrive pulley for your engine, or have one custom made. Slowing your accessory chain by 50% would surely help fuel economy while keeping your vehicle practical. Also look into reducing your electrical load (LED tail/signal lights, HID headlights, etc).

[diesel_john]

Originally Posted by Frank Lee

I've got a spare. So I'm sposta hook what to the where?

If you pipe your exhaust into the SC compressor, will the shaft turn an alternator direct coupled to it.

The idea is to extract a bit of energy from the exhaust gas converting it to electricity that can be used for driving accessories.

Thermodynamically, it would look like a pressure drop across the compressor would lower the final exhaust temperature.

the question being would it recover more energy than the added load and friction placed on the engine?

don't know maybe it would be better to stroke the engine and sleave the bores to get more expansion the first time around in the engine.

[Duffman]

I'm pretty sure Frank was kidding.

[JoeBob]

I'm puzzled...how would driving the alternator off the drive shaft (front axle, etc) cut energy usage? It would still have to turn to put power back into the battery. And it is still going to require as much energy to turn whether the energy is coming from the crank shaft pulley or whether it is coming from a pulley grafted onto an axle shaft.

As for cutting off the alternator output, how much gain can be derived thereby? I have driven cars with defunct alternators/generators a number of times, and while I've never quantified the gas mileage, I never noticed any significant power difference. I did, however, notice a significant dimming of the headlights...this was driving from about the midpoint between Baker and Barstow, CA, to Barstow. Had to get the battery recharged and then was able to drive home to Glendale the next day. Of course it was a very quiet trip...I was afraid to even turn on the radio...it was an old Rambler with a tube radio.

I wonder also about battery life...if the alternator is disconnected you are pulling the battery down a lot more than it normally would be...car batteries are designed to give a lot of power for starting, but not designed for continuous loads. Are you saving a tenth of a mpg or two and trading for shortened battery life?

[LostCause]

The most logical thing would be to lose the alternator and charge a deep cycle or alternative (NiMH, Li-ion, etc.) battery at home. Use the waste heat of the exhaust to improve engine efficiency, not drive an unnecessary accessory.

- LostCause

[MetroMPG]

Originally Posted by JoeBob

As for cutting off the alternator output, how much gain can be derived thereby?

A lot: Plug-in Blackfly: going alternator optional nets +10% mpg

AndrewJ just did that to his Civic, and noted an even larger mpg boost.

I wonder also about battery life...

You wonder correctly. This will destroy a conventional starting battery pretty quickly, as you mentioned. So unless you have a supply of free or cheap batteries (with enough capacity), this mod makes no sense from a financial standpoint.

[JoJotheTireMan]

Just a quick thought on this concept, what if you used a deep cycle battery and somehow combined an alternator with an ac compressor clutch, you could then keep your alternator in the car and simply use a toggle switch to engage/disengage the alternator drive.
Add some solar panels to the system to help with charging.
Maybe even automate the switch on/off depending on the voltage at the battery.
Just some thoughts, take them as you will. JoJotheTireMan

[JohnnyGrey]

On a car, solar panels aren't worth their weight. The only reason I have one on our other car is because my sister goes weeks without driving it. It prevents the battery from going flat.

[diesel_john]

Originally Posted by Frank Lee

A: I wasn't kidding about having a spare Super Coupe supercharger sitting around- not only a barn full, but a house full as well!

B: Sure wouldn't want to pipe exhaust through it tho'! (didja mean Turbo Coupe?)

True the test could consume the SC turned gaseous powered motor. If however diesel's are dirty as everyone says they are then after the test it should have a very fine coat of nice lubricating lampblack sealing all the little nooks and crannies. Exhaust temperatures for the rabbit are only 300 or 400F.

Besides it would be still good to look at and sit in the living room.
A slight devaluation for the advance of science.

I'll Try it first with an old smog pump or two and see if it melts anything.