
Ford’s electric supercharger  - yitchelle
http://theage.drive.com.au/motor-news/fords-electric-supercharger-20120703-21esd.html
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ars
95 grams of CO2 while burning gasoline will get you .4 kWh.

If you drive 120 KM/h then you can a most generate 46.8KWh of energy during
that hour. (.4 KWh for each km.)

Divide by an hour, and that gets you 46.8KW of power. And that is assuming
perfect usage of every bit of energy in gasoline which is of course
impossible.

So how in the world do they develop "110kW while emitting just 90-95 grams of
CO2 per km". It's completely impossible to produce that much power.

You would have to drive at 282 KM/h in order to do that.

Unless I have a math error. Or whoever wrote up that story completely got
their facts wrong.

(When checking my math be careful not to mix up power and energy. And I hope I
didn't mix them :)

~~~
snippyhollow
I don't think you're pumping 46.8KW continuously when driving at 120KM/h, so
you're not getting 46.8KWh of energy... The targeted 110KW is for when you're
accelerating (a lot, or going really fast and having a lot of air resistance,
or tracting something huge). While not still exactly there (110KW / 95g
CO2/km), it seems possible, look at Citroen's engines (and CO2/km ratings)
<https://en.wikipedia.org/wiki/Citro%C3%ABn_C3#Engines_2> or the engine of the
Smart (fortwo) <http://en.wikipedia.org/wiki/Mitsubishi_3B2_engine>

~~~
ars
> I don't think you're pumping 46.8KW continuously when driving at 120KM/h

Certainly. But then you are not really developing "110kW while emitting just
90-95 grams of CO2 per km" are you?

Unless that's some sort of PR speak for an engine with a maximum power of
110kW that emits 90-95 grams of CO2 per km during a normal drive (but that's
not a function of the engine). But if so, that's a rather misleading way to
say it, since that's the car not the engine.

~~~
maxerickson
The following paragraph clarifies the CO2 emissions figures.

I think it is fair to call the text terse, but there is plenty enough context
to avoid being mislead.

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lostlogin
Gawd, you were thinking a a higher level than me. I was remembering gluing a
CPU fan to a 2 stroke scooter and being impressed how much better it made it
(it went from extremely underpowered to very underpowered). I probably ruined
the motor, but it sure was fun.

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adrianN
I've never driven a car with more than 60HP and they did everything cars are
supposed to do, including accelerating quickly enough to safely enter the
autobahn. Can someone please explain to me why people need 150HP engines
unless they're pulling a trailer?

~~~
bane
I'd love to know what the list of cars are that you've driven where 60HP was
the ceiling. About the only car on sale these days that's down in those ranges
might be a used smart -- I think even all of the new ones make at least 70hp
(52kw). Even the Ka I think bottomed out at 70hp and every time I saw one of
those on the autobahn drivers seemed to spend more time trying not to collide
with it than it did maintaining any kind of decent speed.

I can attest to having driven several cars at several HP ratings on the
autobahn and felt terrified in cars that spent 13-15 seconds getting up to
100kph let alone the kinds of speeds most of the traffic was going. It wasn't
until I picked up an Audi A3 that felt even remotely safe in day-to-day
autobahn driving. At least Germans tend to drive better than Americans on
those kinds of roads and do a good job of maintaining the appropriate lane for
traffic going their speed. But still, top end of 60HP on the _autobahn_?
_shudder_

edit: For reference, here's a 60HP Peugeot with the engine absolutely pegged
on the Autobahn doing about 160kph (about 100mph) and getting passed like it's
standing still a couple of times.

<http://www.youtube.com/watch?v=1ut11emid94>

~~~
revjx
My first car was 55HP - that was in 2004. It's not that uncommon, in the UK at
least, for smaller, older cars. Plus horses seem to escape over the years.

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ars
"grams of CO2 per km" is a very strange way to rate an engine.

It makes sense for a complete car. But just an engine by itself? Without
specifying the speed of the car, weight of the car, aerodynamic shape, type of
fuel?

~~~
lloeki
They have a model to estimate various features of the car or they take it live
from real cars, and deduce the resulting opposing force at speeds to counter-
apply on the engine when bolted on a test bench.

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Mordor
Hopefully with fewer rare earth metals too :)

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jacques_chester
The most interesting part of this is that this design decouples the
supercharger's speed from the engine's.

~~~
lloeki
Indeed, as at first I thought it was just like Honda's IMA, which removes the
starter entirely, and replaces the whole flywheel with an electric motor[0].
Here's a graph [1] showing the huge low-end torque boost of the CR-Z electric
engine. It's clear that putting a regular turbo (like Ford is doing) would
certainly help torque on higher revs.

Toyota's HSD has two motor-generators, one to boost low end torque (MG2 or
MG-T), and one higher up for speed (MG1 or MG-S). They do not operate in the
same mode at the same time, one acting as a generator for the other that acts
as a motor. As such it resembles the principle of a supercharger, in that it
takes unused energy to apply it somewhere else on the drivetrain. Both motors
do slip and they actually use that as a CSV transmission to replace the torque
converter in a auto gearbox. Contrary to Ford's solution where the electric
"supercharger" motor drives the driveline, there is no actual uninterrupted
physical connection between the engine and the wheels.

While we're doing a round up of hybrid technologies, Peugeot insisted on
creating a hybrid diesel engine and could not overcome reliability problems
when designing an engine similar to IMA, so they went back to the drawing
board and simply made the two systems independent yet synchronized: the
electric motors drive the rear wheels while the IC engine drives the front as
usual.

[0]
[http://upload.wikimedia.org/wikipedia/commons/f/f2/Honda_Ins...](http://upload.wikimedia.org/wikipedia/commons/f/f2/Honda_Insight_IMA.jpg)

[1] [http://www.automobile-sportive.com/guide/honda/crz/crz-
graph...](http://www.automobile-sportive.com/guide/honda/crz/crz-graph.jpg)
(power in orange and torque in red, bold line is with electric and thin
without)

