Electric Assist Project: E-charger (2000 Subaru Outback)

[brucey]

Henshao: I wouldn't expect such an improvement if I wasn't heavily subsidizing the gasoline with electricity.

Frank: Yup on all parts. The lack of not being able to coast in neutral is what's limiting me here. Just as others predicted. I'm just slow I guess. (:

Sid: You're welcome! I'm learning a lot myself. (:

Shadetree: It's doable. But I think I'd much rather go for a neutral coast ability. The efficiency should be much better, although it also means I'll be lacking proper gearing in all scenarios.

Everyone else: I don't even know how much electricity I've used as my Kill-a-Watt was stolen (long term borrowed) but I'm sure it's a lot, and my gas usage has barely gone down any. 33~35 mpg is about the best I can do city. So with that in mind, I'll be removing it from the car and going back to the drawing board. I really like the idea of a powered trailer since I already have a 4x8 and I'd have plenty of room for major battery power. All I'd really need is an old axle.

[henshao]

Shadetree, that's brilliant. Brucey make sure you put an air filter on your 'leak.' One thing to be wary of is leaning the car out in this manner will cause it to richen the mixture. The MAF will be fooled but not the o2's. I believe some guys interrupt the signal from the camshaft position sensor in order to accomplish fuel cutoff.

[Phantom]

I think the reason that the car has troubles with DFCO is because it is not making enough power to turn the electric motor so he has to add air. To adjust for this it would be easiest to open the throttle at close by adjusting the throttle stop screw to test a hole could be added if needed or wanted in the throttle plate.

I see it as a success if you can keep it charged looking at your fuel log you were getting 31-37 mostly Highway and were getting 24-27 city. If you are now getting 35 in city that is ~28% increase (from 25mpg to 35).

Do you have the controller set up to charge the batteries?

[henshao]

Cars these days are programmed to bump up the idle speed when the A/C compressor engages for just that reason...the difference being Brucey's motor is always engaged.

I think these tweaks will have a profound effect.

[gor]

Bruce, great thanks for your research and build
to make experiment not on test mule, in lab. environment, but on the field, with your own car without resources - with all you've got - man, you are true hero

Bruce, after week of testing (before you took it off) - what are your thoughts and suggestions on DIY BAS systems or similar?

remember, on the beginning of the thread (p.3):

DCB:
I offer my gph readings from my 1.9 liter saturn warmed up in neutral if you would like to try to make sense out of them:
RPM GPH
1000 0.35
2000 0.65
3000 0.80
4000 1.02
__________

[gor]

below is power/torque curves for 2.5L engine (pt cruiser and dodge neon - not outback, but close : ) combined with your ac-12 ( sorry for being power freak : ))))




you can see after spike at 2000 rpm torque goes down (chart in right corner)

if you gear it up (1:2.5) - you'll have constant torque increase up to 5000+ rpm (and more power near readline)

[unheardofinstruments]

I think you guys need to see the electric hubcap project, suits any car and seems just as simple and axial flux motors are much more efficient and light due to the reduced back emf. I am doing an all electric so I can use the inside of the CV's instead but if you are thinking hybrid from stock ICE car it seems the go.
//members.shaw.ca/Craig-C//hybridize/hybridize.html

[bwilson4web]

Hi,

Originally Posted by brucey

. . . my gas usage has barely gone down any. 33~35 mpg is about the best I can do city. So with that in mind, I'll be removing it from the car and going back to the drawing board.

What control do you have over the motor power?

The video suggests ON/OFF versus the ability to add fractional power. ON/OFF suggests it is an acceleration aid versus something that could help in a steady state. Was this just a manually controlled motor versus one integrated into the car?

A suggestion, you might keep the configuration, perhaps remove the heavy batteries if the car has normal commuting duties, and look at instrumentation and data recording. With quantitative numbers, you may be able to excel model the energy flow.

It may be that the unit can offset the inertial loss from acceleration. Too bad it has no regenerative capability to try and recover some of the kinetic energy when stopping.

What you've built looks like a home-made, belt assisted hybrid similar to the GM 'micro hybrids.' My studies of such cars from Fuel Economy as well as lay reports suggests their actual mileage has always been modest.

Originally Posted by brucey

. . . I really like the idea of a powered trailer since I already have a 4x8 and I'd have plenty of room for major battery power. All I'd really need is an old axle.

The assumption is this architecture scales better than the previous GM micro-hybrids and BAS systems. I would be interested in seeing a model that shows this to be the case before beginning a big build.

Another approach is to build an electric car with a range extender motor-generator. Even lead-acid battery, electric cars have about a 20-30 mile range. So adding the range extender, especially a diesel driven generator, might be more successful.

Regardless, I admire your effort and energy. It is too easy to pontificate without 'turning a wrench' or doing the experiment.

GOOD LUCK!
Bob Wilson

[brucey]

Phantom: The motor is capable of regen, but it's usually not right now (At higher rpm, I can see it feeding 10 amps or so) The batteries are charged by the grid charger.

Gor: What I can with what I got! I haven't disassembled it yet, just disconnected it. My thoughts are it's possible to get a system like this to be efficient, maybe even have regen capabilities with proper batteries.
But I'm thinking it will be easier, and a lot more efficient to simply have a neutral coast ability. It doesn't help that my car is an automatic so I'm fighting the transmission as well as the engine for delivering power to the wheels.
That said, with a lot more tinkering I could see this being very helpful if I were to get a smaller engine in the car. Thanks for the graph overlay as well. Check out my 2.5 SOHC torque curve a few pages back. A lot flatter than the PT cruisers.

Bwilson4: I can independently control the system. The hand throttle allows me to give it as little or as much power as I want. A completely EV vehicle is also an option, but honestly parking is getting limited at my place and my town has some steep (14% grade) hills. I'd be worried about it not being capable of simple city trips.

[Phantom]

Have you considered adding an injector kill switch? If you did that you could warm the engine then cut the injectors at a stop or roll as you do this open the throttle 100% and use the electric motor to turn the engine and trans for city driving. That would reduce pumping loss and should keep the electronics on in the car, the one thing you will need to remember is to let off the throttle and shift into neutral when you are ready to restart the engine.