Elmo P. Shagnasty <elmop@nastydesigns.com> wrote:
> In article <dgkjd5$96d$2@blue.rahul.net>, dold@XReXXAllXn.usenet.us.com
> wrote:

>> I was interested in the 06 Civic Hybrid. Someone said that it can now
>> operate in electric-only mode at low speeds, which would require some
>> redesign, maybe moving the IMA to the other side of the CVT, and making it
>> direct drive.

> Not at all. They merely beefed up the battery and the motor. It's the
> same old IMA, just stronger. Then they rewrote the controller software
> to accommodate that.

> It already stops the engine at traffic lights; now, it can keep the
> engine turned off for brief spurts up to 30mph.

The IMA is mated to the crankshaft. The engine has to turn if the IMA is
turning. It wouldn't seem to be very efficient to turn a dead engine. The
VTEC can shut the valves off, so there is less pumping energy needed, but
there's still a lot of mass and friction.

If the IMA were moved to the other side of the transmission, it would be
more efficient, but that would be a substantial redesign. That would also
limit the top speed to some moderate speed.

The articles that I've read don't comment much about the "idle stop" except
to say that it is used more often in the new model. One review does say
that the VTEC shuts down all of the valves during low speed steady state
operations for IMA-only drive. Another review notes that they could never
get the IMA to drive the car with the engine off. Maybe the tach still
indicates the motor speed, and they couldn't tell, maybe it is really hard
to maintain the low load.

Ah, here's a good one:
http://www.treehugger.com/files/2005...mation_abo.php
with a link to http://world.honda.com/news/2005/4050705_b.html

The VTEC is now more of the traditional VTEC. My 2003 only has "normal"
and "cylinder shutdown" modes. The 2006 has idle, low, and high speed
cams.

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Clarence A Dold - Hidden Valley (Lake County) CA USA 38.8,-122.5