Hybrid Car – More Fun with Less Gas

Jungle Motors Prius Plug In Kit - Page 5

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Posted by Was Istoben on January 30, 2009, 6:54 pm
 


That isn't the way I read David.  I understand the ICE is running at that
time simply to bring your catalytic converter up to temperature.  Under this
condition the computer is telling the ICE to run even if shaft power isn't
needed.  Same goes for the climate control system demanding heat.


Posted by Ike on January 30, 2009, 8:02 pm
 
It's interesting that after owning my '04 for more than five years (yes,
I was an early adopter!), and observing countless discussions among
people with significant tech skills, I've found no consensus regarding
the fundamental operation of the system!

Early on, I installed a ScanGauge and also a multiled indicator that
shows regen braking, friction braking, and ICE fuel pump power. The
ScanGauge permits selection of engine load, rpm, water temp, and many
other parameters - and displays any set of four. Lots of data.

Observing that information, it's still not easy to understand what's
really happening in this car. Driving 60mph, for example, when I take my
foot off the gas the engine "quits" (fuel pump stops delivering) and rpm
falls but not to zero. The only things of which I'm certain is that the
car will run perfectly and economically.

But like my wonderful wife of nearly four decades, "understanding" is
not a prerequisite to "satisfaction". I like this car a lot!

Ike

Posted by Ike on January 30, 2009, 8:03 pm
 It's interesting that after owning my '04 for more than five years (yes,
I was an early adopter!), and observing countless discussions among
people with significant tech skills, I've found no consensus regarding
the fundamental operation of the system!

Early on, I installed a ScanGauge and also a multiled indicator that
shows regen braking, friction braking, and ICE fuel pump power. The
ScanGauge permits selection of engine load, rpm, water temp, and many
other parameters - and displays any set of four. Lots of data.

Observing that information, it's still not easy to understand what's
really happening in this car. Driving 60mph, for example, when I take my
foot off the gas the engine "quits" (fuel pump stops delivering) and rpm
falls but not to zero. The only things of which I'm certain is that the
car will run perfectly and economically.

But like my wonderful wife of nearly four decades, "understanding" is
not a prerequisite to "satisfaction". I like this car a lot!

Ike

Posted by David T. Johnson on January 30, 2009, 9:11 pm
 Chas Gill wrote:

There's no transmission or clutch on the Prius so it is impossible for
the ICE to move the car in the reverse direction since the ICE
crankshaft will only rotate in the direction that moves the car forward.
  The ICE can (and does) start when the car is moving in reverse but,
since it is rotating in the 'wrong' direction it rotates against the MG2
rotor and runs only MG1.  If you play with the flash simulation you'll
see that if it runs too fast the generator will overspeed so the
computer optimization is to keep the ICE off in reverse unless it's
needed to charge the battery.  I haven't tested this on my '06 Prius but
from just the simulation, it looks like the MG1 will overspeed if the
vehicle goes faster than 20 mph in reverse with the ICE on so I would
presume that the computer will shut the ICE down if the vehicle speed is
more than 20 mph in reverse (which wouldn't be a typical way to drive
anyway).  On my Prius, normally what happens when you shift into reverse
is the ICE shuts down and reverse is electric-only with the MG2 powering
the wheels.

--
Posted with OS/2 Warp 4.52
and Sea Monkey 1.5a

Posted by Elmo P. Shagnasty on January 31, 2009, 3:58 pm
 



Only if the ICE isn't needed for other things--such as warming up the
catalytic converter or providing cabin heat, or providing charge to a
fully (relatively speaking) discharged traction battery.

For those of us who get in in the morning and back out of our garages,
typically the ICE will run as soon as the coolant is pumped back out of
the vacuum bottle and the system knows the temperature state of the
engine/coolant.  The engine runs even though we're backing out.

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