Test: Alternator vs. no alternator = 10% MPG gain @ 70 km/h

[oil pan 4]

Alternators need to spun to at least 800 RPMs to get any amps out of them.
Only reason I know this is I had a car that wouldn't charge at idle once. The alt wasnt under driven at all and was a beefy AC/delco 95amp unit. The problem is the car was idling at about 200-250RPM.
I conneced an amp meter in serries with the alt and was getting nothing, then conneced a tachometer to a spark plug wire and it would barely read.

Normally alts run at 3x crank speed, most of the time when you underdrive them you turn them at 2x crank speed and then there is "race underdrive" which turns the alt closer to 1 to 1 or 1.5x crank speed.

Most of the A/C clutches I have seen would put an alt close to a "race underdrive" state of operation.

[mans]

Originally Posted by MetroMPG

• Green Car Congress: TIGERS: Exhaust Gas to Electricity for Reductions in Fuel Consumption
• http://ecomodder.com/forum/showthrea...ner-13023.html
• http://ecomodder.com/forum/showthrea...tor-15679.html
• http://ecomodder.com/forum/showthrea...ator-9447.html
• http://ecomodder.com/forum/showthrea...tive-8796.html

Metro mpg, thanks for these links.

a homemade version of this would push us very far, with the deep cycle battery of course.

if engine will no longer be driving the alternator, you can delete the water pump too in place of an electric one without worrying as much about the ewp power consumption.

its nice to delete the alt AND the water pump leaving a de-loaded engine and still have electric power to power the accessories.

for now we'll just disable the power steering and leave the a/c off.

the question is whats the best way to do this...
I'd think to take the stock pully from the alternator and put it on the turbo(we'll figure out how) then we put a larger diameter pully (like a crankshaft pully size) onto the alternator , and now run a belt between the two. there are many types of belts available, that you can custom cut as necessary- like the leather commercial sewing machine belts that u cut to size and they go together with a metal hook (and they last for years on a commercial sewing machine, perhaps 3months on a turbo but thats enough to start us off (-and i'll bet these are avail in rubber too for longer life)

now with some aeromods and we will be bragging cuz the p&g will be waaay better cuz theres no power being sucked off the pulses by the alternator AND water pump. etc. etc.

sounds awesome, but if it is indeed so, then
how come noone has done this?

ok, where's the part that i'm missing.... if anyone can shed light I'd be appreciative.

[oil pan 4]

Using the engine to drive something is going to result in lower MPG.
An exhaust driven alt falls into that catorgory.

Your only options are to carry more power with you, add a solar panel that doesn't mess up your aerodynamics or put something that uses free and clear waste heat to do work.

[Tesla]

Originally Posted by oil pan 4

Using the engine to drive something is going to result in lower MPG.
An exhaust driven alt falls into that catorgory.

Your only options are to carry more power with you, add a solar panel that doesn't mess up your aerodynamics or put something that uses free and clear waste heat to do work.

x2
posted a similar answer on Turbo alternator thread.

[Frank Lee]

Well... other options include improving system efficiency. I'm not willing to give up the ability to drive 8 hours overnight (lights on) without the battery going dead, and I'm not going to lug around any extra batteries and/or a charger to do it. If I'm far away from home, that car had better be able to start by itself out in the middle of nowhere in the middle of the night. To that end, I will not be doing an alt delete either.

Doesn't mean the situation is hopeless.

I can reduce electrical loads. I already have basically done that simply through device management- run heater/defrost fan on low, radio off, lights off until needed. The a/c clutch is disabled.

So now I have this big 95 amp alternator spinning at 2 or 3x crank speed (haven't measured it all yet) plus, as far as the accessory drive system, I have plenty of things I don't want or need. I think all I want is a flat vee belt from the crank to the water pump to an alternator. I've bypassed the power steering pump and ishtcanned the a/c compressor and by doing so can also throw out two idler pulleys.

Car Craft or some such says it's usually safe to under drive water pumps 25%- I'll buy that. They also say to not under drive an alternator by more than 10%... well, that sounds good for the general public, but I think I can go further because I'm trying to economize my car's electrical production/consumption BUT MOSTLY because my car is NOT IDLED, so if the alternator can do it's job at cruise rpms I should be fine. Alternators are designed to take care of everything at idle; as a result they go way faster than necessary at cruise speed. A 25% undersized crank pulley would take care of it all. I was considering installing a far smaller alternator too, but heck, they're expensive and the stock one is all set up for the wiring.

I won't get the "10%" reduction of an alt delete, of which supposedly 5% comes from belt delete to it and 5% from the alt itself? I think I can expect an fe increase of up to 10%, though, because of my accessory drive simplification program.

[IsaacMTSU]

Originally Posted by Ladogaboy

There has already been talk about converting standard internal combustion cars into hybrids by installing an electrical start/stop motor. Installed properly, couldn't that motor also serve as an alternator during deceleration, braking, etc.? It would probably be very difficult to pull off, but it seems feasible to me.

Sorry, I didn't read the last two pages, maybe someone said it already, but that's what Honda's Hybrid IMA system is. Works awesome on our CR-Z

[California98Civic]

Originally Posted by Frank Lee

Well... other options include improving system efficiency. I'm not willing to give up the ability to drive 8 hours overnight (lights on) without the battery going dead, and I'm not going to lug around any extra batteries and/or a charger to do it. If I'm far away from home, that car had better be able to start by itself out in the middle of nowhere in the middle of the night. To that end, I will not be doing an alt delete either.

My alt is on a switch. I plug the car in at night at the bumper (into a 6amp maintainer in the car, connected to the battery). Normally, my alt does no work at all day-to-day. Whenever I need more range, I flip the switch and I am back to stock alt function.

[Frank Lee]

That's good for daily commutes but I do mine on bicycle. Still, I'm considering the field switch as well.

F.Y.I. I've seen a credible analysis that says vehicle-generated electricity costs 4x what household electricity does... I saw the figures he used to do that calc; my electricity is much cheaper so the electricity I use in my car probably costs 5x what it does at the outlets in my house!

[Ladogaboy]

Originally Posted by IsaacMTSU

Sorry, I didn't read the last two pages, maybe someone said it already, but that's what Honda's Hybrid IMA system is. Works awesome on our CR-Z

I'd have to go back and check, but I believe I was referring to a different, contemporaneous thread. The IMA system is fine, but it is integrated between the engine and the transmission. While the functionality is the same, I'm referring to removing both the starter and the alternator from a conventional ICE setup.

The work necessary to create the functionality to replace both the alternator and starter and integrate that with the rest of the car's systems is daunting to say the least. The Insight and the CRZ have the benefit of a cadre of engineers backing them.

[IsaacMTSU]

Oh yeah, It would be hard to make something like that yourself that works the same way (starting and charging).