The Zing! (Custom-built prototype hybrid tadpole trike)

[Frank Lee]

Originally Posted by cfg83

Frank -
Is there a lesson-learned here from Aptera, aka DO THE ICE first?!?! That way they'd have something on the road ASAP and would be able to test the rest of the components under real-world conditions.

CarloSW2

Or EV first? I don't know if that matters as much as not putting a bunch of money-grubbing fast talkers in charge. That doesn't seem to be the case with Zing.

[NeilBlanchard]

Frank,

I understand the issues of a series hybrid, but they have advantages that outweigh the problems I think. A mechanical drivetrain means that the RPM of the engine must be varied, and it must idle. The engine in a series hybrid runs at a single RPM into a fixed load, so it only needs to meet the *average* load; not the peak. So, the engine itself can be much smaller to begin with, and this then saves weight and size on the related systems.

Ken Fry talks about only having to run the engine half of the time while driving; even when starting with say only 30% charge at the beginning of the drive. Running the engine for *half* the drive at it's peak efficiency the whole time sounds like it is going to be a lot more efficient to me.

[user removed]

Grandfather on my mothers side grew up in a dirt poor family with practically no education. He would pull the engine out of the car on Monday and put it in his dead rise, work the water all week and put it back in the car Friday night. He could only afford one engine. After a couple of years he saved enough to get a Chrysler engine for the boat.

Make it so you can run either or power units together or independently. Plug and play separately or together.

regards
Mech

[Rokeby]

Old Mech,
Great story/memory. Thanks.

Darn few of the folks out there have any idea what a (beloved) deadrise is.

I hope you don't mind If I hep them to a little understanding.



The Chesapeake Bay deadrise is a type of traditional fishing boat
used in the Chesapeake Bay. Watermen use these boats year round
for everything from crabbing and oystering to catching fish or eels.
Traditionally wooden hulled, the deadrise is characterised by a sharp
bow that quickly becomes a flat V shape as you move aft along the
bottom of the hull. There is a small cabin structure forward and a
large open cockpit and work area aft.

The deadrise design was developed around the 1880s for sailing
vessels such as the skipjacks of the Chesapeake Bay. "Deadrise"
refers to the line rising upward horizontally from the keel rabbet
(the point where the top of the keel connects to the hull) to the chine
(or sideboards). It rises on each side of the keel in a straight line, or
"dead rise," creating the flat V shape of the bottom of the hull.
A V-bottom is easier to build than a round bottom. It also has a
shallow draft of two to three feet, making it ideal for the shallows
of the Bay as well as being very forgiving when the Bay turns rough...
Chesapeake Bay deadrise - Wikipedia, the free encyclopedia

[Ken Fry]

Originally Posted by kach22i

Cool looking, but I would want something taller to be seen in daily traffic, and a back seat would be nice too.

Thanks, Kach22

The production version will be the about the same length and height as a Corvette, and will seat two in tandem.

[Ken Fry]

Originally Posted by Old Mechanic

Make it so you can run either or power units together or independently. Plug and play separately or together.

regards
Mech

Wonderful story!

The electric and gas operation are independent... kinda. You can run it on electricity alone all the time, if you have a consistent routine, and drive less than 15,000 miles per year. You can also start out with nearly dead batteries and drive it on gasoline alone, with the genset set charging the batteries and supplying the steady-state motive power needs. (In this mode, in suburban/urban traffic, it gains about 1% charge per mile driven.)

This is where the "kinda" comes in. For good performance, the batteries have to supply more power (briefly and occasionally) than the very small engine can deliver. The batteries also absorb energy from regenerative braking. So, while I can make the Zing! go with the batteries entirely disconnected, it really needs the batteries for good performance.

Thanks again for the inspiring story.

[Ken Fry]

Originally Posted by Frank Lee

Or EV first?

It really doesn't matter too much. The important thing is to decide to do something... and then do it.

Regards, Ken

[Ken Fry]

Originally Posted by cfg83

Frank -

Is there a lesson-learned here from Aptera, aka DO THE ICE first?!?! That way they'd have something on the road ASAP and would be able to test the rest of the components under real-world conditions.

CarloSW2

The Zing! was first powered by an ICE for the reason you mentioned. There is an axiom in building experimental aircraft: An experimental engine in a proven airframe is OK; an experimental airframe with a proven engine is OK; an experimental engine in an experimental airframe is asking for trouble.

The 4 wheel Aptera is probably the best indicator of the overriding problem at Aptera -- they were unable to commit to a project and see it through. Even before having a production three wheeler, they were working on giving up on three wheels for four, and planning to compete with Detroit and Japan.

It's as if they came into it with the software attitude: we'll build something cool, get some buzz, and figure out how to monetize it later.

[Ken Fry]

Originally Posted by Frank Lee

The engine might be 32% but it's putting the power to the ground via generator then battery then electric motor then transmission(?) then wheel vs engine/trans/wheel.

For that putting the ICE power to the wheels seems like a no-brainer.

Hi Frank,

The Zing production version has 40 electric HP. But it doesn't need anywhere near that to cruise along at 60 mph (where it uses about 8HP). It uses 40 hp to accelerate really hard and to and go up steep hills. Most of the time, the motor puts out very little HP, which it can do efficiently -- that's the key advantage of an electric motor.

An engine, however, does not operate at light load efficiently. This is why a Lamborghini, a very small car, gets rotten mileage: in ordinary driving, where it is using 2-4% of maximum power, the efficiency is awful: 6%, 7%, 8%, etc. Thus the 12 mpg rating in the city. A Prius of the same weight gets 50 mpg, due mainly to hybridizing.

The hybridizing idea is to make a very small engine run at or near full load, where it is most efficient. In the Zing! the engine runs at full efficiency or not at all. If I had a 40 HP gasoline engine (like a detuned Geo Metro or Daihatsu) I'd spend a lot of my time operating at less than 20% power, where efficiency is poor (around 12%).

You are right that there are losses in the generator, motor, and controller. (The batteries are mainly out of the picture at a 60 mph cruise). With the Zing!, I get efficiencies of 32%(eng) x 90%(gen) x 98%(cont) x 90%(mot) = 25.4%. So I'd expect that the Zing! would get 50 mpg with a 40 hp gas engine, and about double that as a hybrid, using an engine that operates at 8HP continuous.

Obviously 8 HP is not enough for good performance... thus the batteries, which permit 40 hp outputs for hill climbing and acceleration.

Where does all this fall flat? Suppose I want to drive across the country at 85 miles per hour, the Zing!'s top speed. The engine is not large enough to support that for hours at a time. Your average cruise speed needs to be more like 65. Plan in advance for really big mountains -- this is why the Volt has a mountain mode to accumulate charge before you get there.

[Frank Lee]

Thanks for the data. I know people have their reasons for employing/liking gensets, but as I've stated, I have my reasons for not warming up to the concept. I am fresh off a 350 mile drive and so had time to think about it.