Alternator Delete Mod ::: MPGs

ckruzer

Infidel
Joined
Jul 2, 2015
Location
asheville nc
Been reading up on this. Seems like a really doable theory with some more practical solutions other than a deep cycle being charged by rooftop solar panels or charging the battery every night.

As with generators, the more draw the harder it is to spin. Robbing engine energy. People are deleting their Alts and using deep cycle batteries to do small trips (typical home->work, work->home) and recharging at night. While some hippies get a vw van with solar panels on the roof.

All impractical for an A-typical lifestyle. However...

Cons: battery discharge is damaging

Ive been thinking. If one could electronically cycle their alternator on and off by designing an inline module that goes off battery voltage... Its a thought.

Curious if anyone else has done anything along the same lines. Im still the biggest supporter though that the biggest damage to MPG is caused by friction, and the only true route to increasing MPGs is by decreasing friction. Still - its a quite interesting theory.
 

CasterTroy

Motarded
Joined
Mar 21, 2005
Location
Wallburg
This is so confusing to me. If fuel were $38 a gallon.....maybe


1_Wez.jpg
 

VortecJeep

Powered by Uranium-235
Joined
Aug 24, 2005
Location
Concord, NC
I’ve seen websites on this too. I can’t remember what they are called, people wanting to get ultra-mpgs, or something. They’ll remove the passenger side mirror, passenger side windshield wiper, back seats, spare tire, anything they don’t absolutely have to have to shed weight to gain mpgs.
 

CasterTroy

Motarded
Joined
Mar 21, 2005
Location
Wallburg
They’ll remove the passenger side mirror, passenger side windshield wiper, back seats, spare tire, anything they don’t absolutely have to have to shed weight to gain mpgs.

Sheesh, just buy a cummings! Those things MAKE fuel on the downhill sections
 

jeepinmatt

At least half the people are dumber than the rest
Joined
Mar 24, 2005
Location
Stanley, NC
I’ve seen websites on this too. I can’t remember what they are called, people wanting to get ultra-mpgs, or something. They’ll remove the passenger side mirror, passenger side windshield wiper, back seats, spare tire, anything they don’t absolutely have to have to shed weight to gain mpgs.
Hypermiling most likely
 

jeepinmatt

At least half the people are dumber than the rest
Joined
Mar 24, 2005
Location
Stanley, NC
Disabling the alternator is a fine idea for certain applications, which are all non-OBDII.
 
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ckruzer

Infidel
Joined
Jul 2, 2015
Location
asheville nc
I mean, as long as you realize that's how an alternator already works though, right?

not to my knowledge. its a constant charging system designed to keep the battery charge after using cranking amps and to provide the power needed to run the vehicle. what i am referring to is a solenoid activated clutch system on the alternator allowing it to free spin except when battery reaches Xx% or during braking or idle.
 

Loganwayne

#BTL
Joined
Feb 15, 2013
Location
Clyde, North Carolina
Every time I think I’ve heard some dump shit. Something like this pops up. Really how much fuel mileage are you gaining .1 mpg? .2 mpg? I can get that by the way I drive. What would a system like you saying cost a couple hundred bucks? Time to recover your cost 10-12 years if it is only .1 of a mpg? Your better off spending the money on highway tires and rolling on.


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Chuckman

Well-Known Member
Joined
Oct 9, 2005
Location
Huntersville
it just free spins until its 'charged' anyway right?
 

catfishblues

Well-Known Member
Joined
Jul 26, 2005
Location
Pfafftown, NC
What @Chuckman said. The only parasitic loss is the rotational drag of the alternator when it isn't needed. The load is going to be proportional to the depletion of the battery when it comes online, which I think would blow your theory. That energy has to come from somewhere, and it's going to be your gas tank unless you have an alternate means of charging. I could be wrong, but this reminds me of the underhood hydrogen generators that people were playing with years ago. The law of conservation of energy put those in the dumpster, didn't it?
 

Scooter402

Pissed off Veteran
Joined
Feb 4, 2009
Location
Up yonner in Pennsyltucky
You could probably create one yourself with a handful of Radio Shack parts... simple voltage divider and a logic gate circuit to the clutch. Figure out how to mount an AC clutch to the shaft and you're home free.
 

Scooter402

Pissed off Veteran
Joined
Feb 4, 2009
Location
Up yonner in Pennsyltucky
What @Chuckman said. The only parasitic loss is the rotational drag of the alternator when it isn't needed. The load is going to be proportional to the depletion of the battery when it comes online, which I think would blow your theory. That energy has to come from somewhere, and it's going to be your gas tank unless you have an alternate means of charging. I could be wrong, but this reminds me of the underhood hydrogen generators that people were playing with years ago. The law of conservation of energy put those in the dumpster, didn't it?
Perpetual motion machines... can't happen! It's the law! (Physics, that is... not from the man)
 

Fabrik8

Overcomplicator
Joined
May 27, 2015
Location
Huntersville
not to my knowledge. its a constant charging system designed to keep the battery charge after using cranking amps and to provide the power needed to run the vehicle. what i am referring to is a solenoid activated clutch system on the alternator allowing it to free spin except when battery reaches Xx% or during braking or idle.

Engine load from the alternator is directly proportional to charging/load current from the alternator. If there's no electrical load, there's almost no engine load from the alternator.

If you really want engine load reduction, you can disconnect the alternator output from the electrical system, which is far simpler than using a mechanical disconnect on the alternator drive.

Also, use an electric water pump so you can reduce pumping losses by going to a demand-flow system instead of using a mechanical pump that is based in flow versus engine RPM. If you're not doing stuff like that looong before worrying about disconnecting the alternator, you're just fooling yourself about parasitic losses..
 

Scooter402

Pissed off Veteran
Joined
Feb 4, 2009
Location
Up yonner in Pennsyltucky
I was about to mention electric water pump. Or a water pump drive motor. Those are the poor-man's electric water pump. But, it adds another 12v accessory to account for.
 

Chris_Keziah

Joe Dirt @ Rev Limit Fab
Joined
Dec 1, 2010
Location
Winston-Salem
Why not just put a clutch on the alt. and engage or disengage it based off of system load? Would still need a very good battery to do this and a good controller, not sure you'd gain much at all.
 

Chuckman

Well-Known Member
Joined
Oct 9, 2005
Location
Huntersville
or just drive a smaller car?
 

LBarr2002

Well-Known Member
Joined
Nov 16, 2009
Location
SC
I'm pretty sure GM (probably others as well) have been doing this. The alternators don't charge at all when not needed. The computer doesn't energize the excite circuit until needed.
I've noticed this in my '15. After startup the gauge runs about 15v. After a while if you're just cruising without a lot of draw, it drops to battery voltage, ~12v.
 

braxton357

Robot
Joined
Apr 6, 2005
Location
Morganton
This has been the case for 50 years. What do you think the voltage regulator/ exciter/field wire is doing? Telling the alternator when the battery needs help and to produce voltage/current. If it were always producing 120 amps you would see your battery boiling over in short time. Ever run a generator with no load then turn a saw on? Same concept. I'm sure Ron can explain a lot better than I can.
 

Tim88XJ

Well-Known Member
Joined
Mar 20, 2005
Location
Raleigh NC
GM has been using "variable charging alternators" for awhile now- I think they started around 2007 or 2009 is when they started using them the 5.3 The PCM will dial back the alternator when full amp production is not needed and shut it off to save fuel such as a deceleration event or when not many accessories are on. I discovered this when a friend was considering taking his 2010 Suburban into the dealer because he regularly saw his volt gauge hitting 12v while driving down the highway. I believe we found a TSB on it.
 

moldman05

Well-Known Member
Joined
Jan 27, 2006
Location
Rocky Mount NC
So we want to disconnect the alternator till when? The battery goes dead or when we get home and plug in a charger? Might need a deep cycle battery or 2 to go very far. Why not shut off lights, wipers, a/c fan and clutch, and radiator fan and then the alternator will not have much to do. Then we could go back to it takes less hp to take mechanical energy and make electrical energy to make mechanical energy than just using a belt to drive a fan or water pump.
 

Tim C

Wizard
Joined
Jan 22, 2007
Location
Fayetteville
I'm pretty sure GM (probably others as well) have been doing this. The alternators don't charge at all when not needed. The computer doesn't energize the excite circuit until needed.
Most newer vehicles (last 5 to 10 years) do this. Voltage regulator is pulse width modulated by the engine computer. The ecm looks at ambient temp, engine temp, fan/ac/rear defrost useage, interior temp, idle time, and more and devises a charge strategy. Like stated above youll see 14.5 to 15 volts on startup and itll drop back to 12.5 to 12.7 for a while then cycle. Anything to save. 01mpg to meet federal CAFE standards.

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