Paul,

I ran across this article today. (I had to Google "Chery Automobiles" to
find out what they're talking about.)  Chery is the largest privately owned
auto maker in China.
In a few years, this could turn out to be a good source for small, cheap
800cc, 1-rotor engines.  "C-Spec" rotary engines coming soon!

http://www.chinacartimes.com/2010/10/18/chery-working-on-wankel-engines-for-
new-energy-vehicles/comment-page-1/

Mark

That looks like an AIXRO engine. Several car companies have been
experimenting along those lines.

My prediction is range extender cars will flop in the market place because
they are being pushed by ignorant wacko environmentalist and politicians
that do not understand how cars work. Try climbing a hill with dead
batteries in a 3500 pound car pushed by a Wankel engine the size of a go
kart engine. How stupid can one be? Of course one could stop at the bottom
of the hill for a couple of hours and let the Wankel charge the batteries :)

Paul Lamar

Hi Paul,

Yes, that's our Aixro karting engine. I would be curious to know where that
picture and info comes from.
It still has the karting engine mounts, so if this is as far as they have
come with their R&D, it will take a little while until they have an engine
ready. But who knows? If they can learn from others' designs when it comes
to cars, they will eventually do the same when it comes to engines (and then
figure out that our engines are not suitable for automotive applications:-)
http://en.wikipedia.org/wiki/Chery_QQ

Poul

Paul,

In range-extending cars like the Volt, the battery is never allowed to run
down all the way. This is both to preserve battery life and to provide an
energy buffer so that the motor can make full power--for a short period of
time--even when in range extending mode.

Obviously, sizing the range-extending IC engine requires some thought. You
probably want an engine that can make at least twice as much power as the
average power need during normal driving. This would allow maintaining the
buffer at a reasonable level.

Csaba


P.S. The onboard generator typically does not charge the battery beyond
maintaining the battery buffer. You can leave the Volt stationary and
running forever, and it won't charge the battery.

----------------------------------------------------------------

Suppose the battery is down to the lower limit after climbing a hill.
Won't the engine charge the battery when the car becomes stationary?
Suppose there is another hill ahead?

Do you have any statistical data on car HP usage profiles in different parts
of the country?

The way I see it, in mountainous area like the western states and areas
where driving on two lane roads is the norm, the situation is critical. If
you attempt to repeatedly pass cars requiring full power the battery could
be depleted to the lower limit. Does a red light come on telling you now
have no excess power to pass or does it allow you to be crushed to a pulp by
the on coming tractor trailer?

I assume under no circumstances can one draw current from the battery when
it is at it's lower limit.

Average required power on a flat road for a 3500 pound car at 80 MPH is
about 40 HP. By the twice the HP rule of thumb the ICE charging engine would
then be 80 HP. Assume for the moment the computer is smart enough not to
attempt to charge the  now depleted battery when the driver floors it to
pass, he now has a 3500 pound car powered by only 80 HP. I maintain no
driver in his right mind is going to put up with that situation.

I just helped drive a small block V8 GM truck/van and 4000 pound race car
and trailer from Cal to Elkhart lake over hwy 70 through Colorado and we got
down to 20 MPH at the higher altitudes. Total weight was close to 8000
pounds.

There is a reason why 300 and 400 HP light weight cars are popular. That
amount of HP is available for passing and climbing hills. These cars do not
have to carry around 500 extra pounds of batteries that subtract from the
handling. The actually weight penalty is much higher than 500 pounds, as I
am sure you already know, due to additional structure and larger brakes.

IMHO the automotive world would be much better served investing the hybrid
and range extender R&D money to recovering some of the 50% waste energy in
the ICE exhaust. AKA turbo compound. IMHO the additional cost of the hybrid
and range extender vehicle is better spent on higher strength to weight
ratio materials such as carbon fiber and aluminum.
I also might add higher power to weight ratio engines like the Wankel turbo
compound.

If one examines the Toyota Pris (:)) carefully one will find only part of
the good gas mileage comes from the hybrid feature.
The rest comes from better aerodynamics, higher cost materials and harder
tires with lower rolling resistance. Features that could and should be
applied to any car.

BTW All this stuff is based on the false premise that CO2 is bad.

As far as running out of crude oil the Water Melons are mentally unable to
grasp the concept of negative feed back. About the only mathematical
function they seem to be capable of understanding is a linear extrapolation.

We will NEVER run out of crude as long as price and demand has anything to
do with it. Of course the Water Melons assume they will control the price of
fuel so they will also be able to tell you what you can and can not buy. In
other words, hybrid Trabants or range extender Trabants... take your pick as
long as it is some puke shade of pastel green :)

Here is a picture of part of the ex Trabant factory now owned by my friend
Mario Haeberer current owner of the Wankel trade mark and assets. Notice it
is empty. Mario plans to build Wankels in it in the future.

Paul Lamar



Paul,

I believe that a car like the Volt has two thresholds for battery depletion.
The first threshold is when the IC engine turns on to produce electricity to
power the car. I suspect that it is around 45 percent of the battery
capacity. There is also a second threshold below which the battery is never
allowed to drop--probably between 35 and 40 percent of capacity. The
difference between the two thresholds is the buffer used to let the electric
motor develop full power.

The Volt's drive motor develops a peak of 111 kW or 149 hp. The Generator,
powered by the IC engine can develop 54 kW [72 HP]. Now if my estimates
about the Volt's battery thresholds are correct, then there is between
0.8-1.6 kW-hr of battery buffer available (16 kW-hr. battery x 5-10
percent).

At full power, the electric motor is drawing 57 kW [76 HP] from the
battery-as-buffer (111kW - 54 kW). If we split the difference and say that
the battery buffer can deliver 1.2 kW-hr, then the Volt can run full power
for about 76 seconds (1.2 kW-hr/57 kW x 3600 seconds/hr).

That might not be enough to pull a horse trailer up through Loveland pass,
but the Volt was never intended for that activity. However, I would submit
that 76 seconds of full power is more than enough for most semi-normal use.

Also keep in mind that after you climb a hill, you often come down the other
side and the Volt's regenerative braking can help the IC engine recharge the
battery before the next upgrade arrives.

Of course, you can criticize the car for its cost and that's fair. And I
won't argue about CO2 because I'm agnostic on that issue. Besides, if you
charge the Volt form a coal-fired plant, it's not clear that it achieves any
CO2 benefit.

But for the commutes that the majority of Americans drive, the Volt can run
on mostly electric power at one third the cost per mile of gasoline. If the
cost comes down in the next few years--and gasoline gets more expensive, it
may well find a reasonable market.

Csaba


What is this slug going to weigh? How may pounds of costly and limited
resource copper? What does the battery pack weigh and how long are they
supposed to last? I hope they last longer than the batteries in my note book
computers. What does it cost to recycle all that exotic stuff?

I tested that coast-down-the-hill hypothesis and most cars will not exceed
the 75 MPH speed limit by coasting indicating there is not enough free
energy available to recharge the batteries. The grades were on the 101
between the SF valley and Ventura and the Grape Vine. I also tested this in
Beverly Glen. This is an easy thing to test.

It takes a  lot longer than 76 seconds to get up all those grades at the
speed limits. There are many grades in the west that are just as severe and
also take  a lot longer than 76 seconds to negotiate.

At the head of every moving traffic jam in LA is a Prius :)

BTW what are you up to lately? Got any gigs going?

I  was going through some old pictures for a slide show at my B party and I
found some pictures I took of one of your European trips with Don and
Ursula. You would not happen to have any pictures of that BMW 720 I wrecked
at Hockenheim would you? :) I think Ursula took some.

Paul Lamar

Paul,

I think the Volt weighs about 3700 pounds, though I haven't seen an
independent figure. In any case, it has even power to easily deal with
normal driving situations. Most grades do not require full power on the Volt
or any other car. The assumption that it won't be able to climb most hills
is highly unrealistic.

I don't know how long the batteries will last, but this is hardly an unknown
area. As I pointed out, the Volt doesn't use its full battery
capacity--primarily to extend battery life. This is quite different than you
laptop which typically depletes its battery down to the last 3-5 percent.
Hybrids have now been on the market for ten years and most of them are still
on their original batteries. The warranty for these batteries is eight years
and not many have been replaced.

Most traffic jams I encounter are caused by a pack of Harleys, which are
holding up the Priuses and the soccer moms in their minivans. In any case,
if a Prius is causing a traffic jam, it's not because the car can't go
faster--it has a top speed of 115mph--it's because the Prius driver is an
idiot.

Csaba

I don't know what grades you are testing on but there
are a lot of grades here in California that some of the
smaller cars cannot maintain the speed limit on. Particularly
with several passengers. I have to shift the Honda Odyssey
down with no rear seats (300 pounds less), one person, me,
and 250 HP to make it up the Ventura grade at the speed limit.
Same goes for the RX8. The Prius's are in the slow truck lane
by the time they get to the top.

When the Prius battery is depleted to
it's lower limit the 2010 Prius has only 98 HP to work
with from the piston engine. Earlier models have 76
HP. It is interesting that Toyota is continually increasing
the HP of the Prius's ICE model by model. Obviously even Toyoto
understands the car needs more HP from the gas engine.

The empty weight is 3042 pounds so with 3 FAA 175 pound
passengers the Prius total weight is 3567 with 98 HP.  That is 36 pounds per
HP with no help from the battery. A slug in anybodies book. My 240 HP
RX8, not known for acceleration, has twice the power to weight ratio
with the same gross weight.

I assume the Prius 115 MPH top speed is with a fully charged battery.
The question then becomes for how long?

It does have a claimed low .25 drag number but that could
be applied to any car.

It would be interesting to take out the batteries and the heavy
motor/generator, the power control unit and put in a more powerful
piston or RX8 engine removing 400 to 500 pounds from the empty weight
just to see what she will do :) The weight should be several hundred
pounds lighter than an RX8.


Paul Lamar