It's official. Manual transmissions are making a comeback.

By that way of looking at it, SHS has two transmissions, like pretty much
all cars. The planetary "power split device" is a skewed differential and
could have been made like a typical differential if ruggedness weren't
important. No gears ever shift, there are no clutches or belts or hydraulics
or solenoids or forks. It is all fixed gearing, which makes it different
from automatic transmissions. The device should be bulletproof as long as
the lubricant is kept up, without the weaknesses of manual trannies (no
synchros, no clutch, no gear crunches possible).

The way I describe the system is to visualize an engine connected straight
through to a differential. Instead of wheels, there is a motor/generator on
each side of that differential. Connect another conventional differential
and wheel setup to one side, and there you have it.

Mike

 

Yes, I wonder how they (NHTSA) are defining "manual". Some of the
ones you listed are typical torque converter ("slushboxes") where
they just add a manual shifting mode. Others have actual manual
trannies, just with an electronic clutch, ex: BMW's SMG. I
believe your "Easytronic" is the latter?
[/QUOTE]

My mind drifts back to earlier days....

Around 1970 Renault offered an unusual (okay, *everything* about Renault was
unusual, at least in those days) automatic transmission for the R16. It was
a solenoid shifted manual transmission with a powdered iron clutch. The
clutch was an electromagnet with steel clutch plates inside and the space
inbetween was packed with iron filings. When the magnet was energized the
clutch engaged. (I don't know what did the shifting.) I hear their unique
creation had reliability problems - I wonder why ;-)

The 70s sure were not the good old days of automotive technology!

Mike

 

Yes, I wonder how they (NHTSA) are defining "manual". Some of the
ones you listed are typical torque converter ("slushboxes") where
they just add a manual shifting mode. Others have actual manual
trannies, just with an electronic clutch, ex: BMW's SMG. I
believe your "Easytronic" is the latter?
[/QUOTE]

My mind drifts back to earlier days....

Around 1970 Renault offered an unusual (okay, *everything* about Renault was
unusual, at least in those days) automatic transmission for the R16. It was
a solenoid shifted manual transmission with a powdered iron clutch. The
clutch was an electromagnet with steel clutch plates inside and the space
inbetween was packed with iron filings. When the magnet was energized the
clutch engaged. (I don't know what did the shifting.) I hear their unique
creation had reliability problems - I wonder why ;-)

The 70s sure were not the good old days of automotive technology!

Mike

 

Honda tends to refer to IMA that way, as "electric supercharging" or
something like that. Honda's approach is fundamentally different from
Toyota's - Honda is more focused on the aspect of hybridization as a way of
making acceleration performance independent of engine size. The engine is
sized for hill-climbing capability, and electric is added to give it more
snap. In theory, Honda's IMA can be used to make cars with better
power/weight ratios for acceleration than is possible with an engine alone.
Honda's DualNote concept car
(http://www.supercars.net/cars/2001@$Honda@$Dualnote%20Conceptx.html) was
introduced in 2001, and Honda engineers reported the electric assist gave it
off-the-line acceleration equivalent to a 600 hp engine. When we realize the
technology is in its infancy, the future is amazing indeed.

Mike

 

Honda tends to refer to IMA that way, as "electric supercharging" or
something like that. Honda's approach is fundamentally different from
Toyota's - Honda is more focused on the aspect of hybridization as a way of
making acceleration performance independent of engine size. The engine is
sized for hill-climbing capability, and electric is added to give it more
snap. In theory, Honda's IMA can be used to make cars with better
power/weight ratios for acceleration than is possible with an engine alone.
Honda's DualNote concept car
(http://www.supercars.net/cars/2001@$Honda@$Dualnote%20Conceptx.html) was
introduced in 2001, and Honda engineers reported the electric assist gave it
off-the-line acceleration equivalent to a 600 hp engine. When we realize the
technology is in its infancy, the future is amazing indeed.

Mike

 

Yep. That's how you can have a 50 kW motor, but only a 25 (30?)
kW battery driving it. Sometimes, actually quite often, at least
part of the electric power to drive the second motor comes from
the ICE driving the first motor as a generator. Basically, an
electric transmission. Generally I would not expect that
to be as efficient as a mechanical clutch.

So the Prius system acts as both a mechanical and electrical
transmission.

 

Yep. That's how you can have a 50 kW motor, but only a 25 (30?)
kW battery driving it. Sometimes, actually quite often, at least
part of the electric power to drive the second motor comes from
the ICE driving the first motor as a generator. Basically, an
electric transmission. Generally I would not expect that
to be as efficient as a mechanical clutch.

So the Prius system acts as both a mechanical and electrical
transmission.

 

Honda did report on this. I forget the exact numbers, but it is
something like 1/3 due to the hybrid itself (regen, more efficient
power management), 1/3 engine downsizing and advanced technology,
and 1/3 lightweighting of the vehicle. Something like that.

Same as Prius. See other posts.

Definitely doable. But it all depends what you want out of a
vehicle, and what you are willing to pay. Extended operation off
the battery requires a bigger, higher energy capacity battery.
The cost of the battery (and mass and volume) are pretty much
directly proportional to that energy capacity.

And if you want sustained performance, ex: climbing Baker Grade in
california towing a trailer, you still need a lot of continuous
capability.

 

Honda did report on this. I forget the exact numbers, but it is
something like 1/3 due to the hybrid itself (regen, more efficient
power management), 1/3 engine downsizing and advanced technology,
and 1/3 lightweighting of the vehicle. Something like that.

Same as Prius. See other posts.

Definitely doable. But it all depends what you want out of a
vehicle, and what you are willing to pay. Extended operation off
the battery requires a bigger, higher energy capacity battery.
The cost of the battery (and mass and volume) are pretty much
directly proportional to that energy capacity.

And if you want sustained performance, ex: climbing Baker Grade in
california towing a trailer, you still need a lot of continuous
capability.

 

The efficiency is supposed to be about 90%, considerably less than a manual
gearbox. OTOH, it allows the engine to operate in more efficient ranges more
of the time, so it's an overall gain in city driving. On the freeway it
would be hard to beat a manual tranny for efficiency. (I understand ATs with
lockup come close.)

There is a narrow speed/power mode where MG1 is stationary and the
transmission is strictly mechanical. I think that speed is different in the
first generation Prius (before 2004 MY) than with the second generation,
because the MG maximum speeds are different now.

Mike

 

The efficiency is supposed to be about 90%, considerably less than a manual
gearbox. OTOH, it allows the engine to operate in more efficient ranges more
of the time, so it's an overall gain in city driving. On the freeway it
would be hard to beat a manual tranny for efficiency. (I understand ATs with
lockup come close.)

There is a narrow speed/power mode where MG1 is stationary and the
transmission is strictly mechanical. I think that speed is different in the
first generation Prius (before 2004 MY) than with the second generation,
because the MG maximum speeds are different now.

Mike

 

Definitely. This will probably be an area where hybridization appears last -
towing packages and trucks of all sorts. The IMA approach is still
attractive (in a technical sense) in that it can improve passing ability and
the ability to gain speed after a stop, but I think it will be a long time
before the economics of that make sense. Turbocharging is better for towing
and trucks, and even that still isn't universal yet.

And as to the topic, I've driven manual and AT rental trucks up grades and I
despise autos for that sort of thing. They also bite the big one off road,
especially on slippery snow/mud roads. Throttle/slippage is much easier to
control with a manual.

Mike

 

Definitely. This will probably be an area where hybridization appears last -
towing packages and trucks of all sorts. The IMA approach is still
attractive (in a technical sense) in that it can improve passing ability and
the ability to gain speed after a stop, but I think it will be a long time
before the economics of that make sense. Turbocharging is better for towing
and trucks, and even that still isn't universal yet.

And as to the topic, I've driven manual and AT rental trucks up grades and I
despise autos for that sort of thing. They also bite the big one off road,
especially on slippery snow/mud roads. Throttle/slippage is much easier to
control with a manual.

Mike

 

That has a drawing of a "conventional" (Honda-like) CVT that made me think
the article was all wrong. It's a paragraph or two later that it explains
the Toyota PSD, but even then the picture is wrong. It looks like the MG1
and CE are slaved on a single shaft.

That made interesting reading. Doesn't cover all of the operation, but I
can fill in the rest... MG1 must be the "starter motor". MG2 supplies
regen braking. But I think I understand it now... The oddities are
compromises. It all makes sense.


The Honda Charge/Assist displays what I expect it to display. When I floor
the gas pedal, the assist goes full, and stays there. Because the IMA has
a power peak at 4000 RPM, I would really expect the bar graph to drop off
some above 4000 engine RPM, but maybe that's literary license for the
masses, who wouldn't want the graph to reduce while demand is full.


In the Escape, flooring it gives near full assist for a little bit, then
swings to charge. That confused me, but it is clearer now. That only
happens at higher speeds. (I actually went out and drove the Escape to
test my new thoughts.) It is because MG2 is tied to the wheels, and has a
peak power at some road speed. I might guess that it's 47mph, where the
EPA highway test runs ;-) It is above thirty, and less than sixty. At
about 10mph, going up a steep hill, flooring it leaves it at full assist,
like I would expect, for the duration of my little test run.

The Escape ICE seems to go to about 4,000 RPM under almost any enthusiastic
"gas pedal" position. The MG2 speed would change exactly as the road speed
changed, with good power up to a road speed that I could calculate if I
went back to Graham's page. The MG1 RPM would change inversely as the road
speed increased if the engine stayed at 4,000 RPM.

I don't see how it relates to the "combined HP" being less than additive
between the MG2 and the ICE. The MG2 maximum would be related to road
speed. The ICE could be held at its maximum HP, and the RPM of that has
little to do with the RPM of MG2. The MG1 output would be lower as ICE
went higher, so there would eventually be some electrical starvation as the
batteries depleted, but it seems that you should be able to see maximum MG2
horsepower added to the maximum ICE horsepower, at least for a few seconds,
and maybe only at one particular road speed.

 

That has a drawing of a "conventional" (Honda-like) CVT that made me think
the article was all wrong. It's a paragraph or two later that it explains
the Toyota PSD, but even then the picture is wrong. It looks like the MG1
and CE are slaved on a single shaft.

That made interesting reading. Doesn't cover all of the operation, but I
can fill in the rest... MG1 must be the "starter motor". MG2 supplies
regen braking. But I think I understand it now... The oddities are
compromises. It all makes sense.


The Honda Charge/Assist displays what I expect it to display. When I floor
the gas pedal, the assist goes full, and stays there. Because the IMA has
a power peak at 4000 RPM, I would really expect the bar graph to drop off
some above 4000 engine RPM, but maybe that's literary license for the
masses, who wouldn't want the graph to reduce while demand is full.


In the Escape, flooring it gives near full assist for a little bit, then
swings to charge. That confused me, but it is clearer now. That only
happens at higher speeds. (I actually went out and drove the Escape to
test my new thoughts.) It is because MG2 is tied to the wheels, and has a
peak power at some road speed. I might guess that it's 47mph, where the
EPA highway test runs ;-) It is above thirty, and less than sixty. At
about 10mph, going up a steep hill, flooring it leaves it at full assist,
like I would expect, for the duration of my little test run.

The Escape ICE seems to go to about 4,000 RPM under almost any enthusiastic
"gas pedal" position. The MG2 speed would change exactly as the road speed
changed, with good power up to a road speed that I could calculate if I
went back to Graham's page. The MG1 RPM would change inversely as the road
speed increased if the engine stayed at 4,000 RPM.

I don't see how it relates to the "combined HP" being less than additive
between the MG2 and the ICE. The MG2 maximum would be related to road
speed. The ICE could be held at its maximum HP, and the RPM of that has
little to do with the RPM of MG2. The MG1 output would be lower as ICE
went higher, so there would eventually be some electrical starvation as the
batteries depleted, but it seems that you should be able to see maximum MG2
horsepower added to the maximum ICE horsepower, at least for a few seconds,
and maybe only at one particular road speed.

 

Say again? A quick look at the Yahoo Autos tells me that the 2005
Civic Hydrid is available with a 5-speed manual transmission. The
same goes for the Insight.