Compressed Air powered, zero emission cars - for $6.5K each

"Mike Romain" > wrote in message
...
> wrote:
>>
>> Mike Romain wrote:
>> > wrote:
>> > >
>> > > Mike Romain wrote:
>> > > > >
> <snip>
>> >
>> > Just because your engine is in 'deceleration mode' with no gas pedal
>> > input doesn't mean you have to be racing the engine or engine braking.
>> > That is what the gear shift is for....
>>
>> Quite right, however in practice you do rev the engine higher than
>> idling.
>
> That 'still' comes down to the computer sending 'no' or extremely little
> gas to the engine so the revs make no matter. That is just engine
> braking.
>
> Idle uses fuel.
>
>>
>> >
>> > I can be coasting at 40 mph with my foot off the gas in deceleration
>> > mode and the engine can be turning at idle speed with little or no load
>> > on it. I actually do that all the time or 'drive with the tach' and
>> > then use the gears to slow down when I approach a light or stop sign.
>> > I
>> > don't need the brakes until the last little bit.
>>
>> If I see a red traffic light in the distance my clutch goes in and I
>> coast up to them. In this case there's probably not much in it between
>> our methods.
>
> Again, you use Idle which uses fuel, I coast in gear with no throttle
> and still need the brakes to finish stopping so I am not wasting energy,
> just saving brake wear.

A modern engine with the gas pedal off and the engine revving above a
certain rev will cut off the fuel completely, until the revs get low enough.

On Fri, "News" > wrote:

>A modern engine with the gas pedal off and the engine revving above a
>certain rev will cut off the fuel completely, until the revs get low enough.

From

http://www.techno-fandom.org/~hobbit...rpstealth.html

it sounds like driving a Prius is a fun thing to do. :-)

JoeFischer

Joe Fischer wrote:
> On Fri, "News" > wrote:
>
>
>>A modern engine with the gas pedal off and the engine revving above a
>>certain rev will cut off the fuel completely, until the revs get low enough.
>
>
> From
>
> http://www.techno-fandom.org/~hobbit...rpstealth.html
>
> it sounds like driving a Prius is a fun thing to do. :-)
>

So is a Viper. So is a '69 Charger R/T.

Joe Fischer wrote:

> On Thu, Steve > wrote:
>
>
>>Joe Fischer wrote:
>>
>>>On Thu, Steve > wrote:
>>>
>>>>And in deceleration mode, the ECM cracks open the idle speed control air
>>>>bleed so that manifold pressure rises (vacuum decreases) making the
>>>>engine very much easier to spin.
>>>
>>> Are you an auto mechanic?
>>
>>No, I'm an engineer.
>>
>>
>>> I can't imagine any
>>>idle control to pass enough air to make much difference
>>>in manifold pressure.
>>
>>It makes a difference, because its exactly the same as cracking the
>>throttle open! From what you say below:
>
>
> Do you know the diameter of the port? I would
> guess about 1/4 inch at most.
>

What type engine? What "port"? The mechanism is implemented all sorts of
different ways! Some cars have a stepper motor that actually does just
open the main throttle slightly. As a "for instance" my wife's 3.5L v6
uses an AIS motor bolted onto the back or the intake manifold. The hole
it bolts into is about 1" in diameter, the air inlet pipe to the AIS
from the filtered air plenum is 3/4" diamter, but I have no idea what
the "full open" cross-section of the pintle/seat combination is. Nor
does it matter- in all cases the AIS can run the engine up to around
2000 RPM even with the drivers foot off the pedal, which results in
substantially less manifold vacuum than with the throttle closed.

>
>>> I don't see much difference between the idle air bleed
>>>and a choke,
>>
>>I don't think you know what an idle speed control DOES (also called
>>"Automatic Idle Speed" or AIS by some manufacturers prior to
>>standardization).
>
>
> On fuel injected engines probably, and oxygen
> sensors regulate the fuel to keep the fuel-air ratio.

If that's your level of understanding of engine managment algorithms and
hardware, then how can you postulate claims about how they perform? I
realize that comes off as "rude," but I really can't whitewash it any
more, its just a fact. Sensors don't "regulate" ANYTHING!!! They provide
information to other mechanisms that DO regulate. Fuel injector pulse
widths regulate fuel flow. Throttle position and AIS opening regulate
air flow. The computer itself directly regulates ignition timing. Oxygen
sensors are completely OVERRIDDEN in some operating regimes (wide-open
throttle, idle, and cold engine, just to name the main cases).


>
>
>>Its nothing whatsoever like a choke. It is a separate
>>air feed into the intake manifold (a second throttle, if you will) that
>>is under computer control rather than linked to the driver's foot.
>
>
> It just works in reverse of the choke, all the choke does
> is reduce air flow.

No, No NO!!!! The throttle reduces airflow. The choke INCREASES fuel
flow RELATIVE to the airflow by artificially increasing the "vacuum
signal" at the metering jets in a carburetor, thus enriching the
mixture. AIS is in NO WAY "like a choke." The function of the "choke"
is replaced in electronic engine management systems by increasing the
duty cycle of the fuel injectors beyond what is normal for a given air
mass flow through the engine, thus enriching the mixture. It is quite
undetectable by the driver, unless he's driving with an oscilloscope in
his lap.

>
>
>>It regulates the engine idle speed, and when coasting can be used to reduce
>>intake manifold vacuum to make the engine easier to spin (gasoline
>>engines only, obviously.)
>
>
> If the diameter is small, it can't change manifold pressure
> much,

If that were true, then it couldn't increase the idle speed of the
engine, nor could it maintain the same idle speed with the AC off in
neutral as it does with the AC on in gear. Understand this: ANYTHING
that throttles the engine DIRECTLY affects manifold pressure.


>and I can't imagine why there would be a desire to make
> the engine easier to spin,

Ummm.... maybe to reduce the drag on the driveline while coasting, so
that fuel can be shut off to increase the efficiency of the vehicle to a
greater degree than could be accomplished by shifting to neutral and
allowing the engine to burn fuel while idling against a high manifold
vacuum? Maybe? Perchance? DO YOU THINK!!?!?!?

> sorry we are from different planets. :-)

On that, I can only agree.

>
>
>>> The torque converter clutch does not decouple anything,
>>
>>So what does it do when its released? Keep the input and output coupled?
>>I don't THINK so, Tim. It releases, and therefore DE-couples the input
>>and output shaft, which it had formerly COUPLED.
>
>
> Not hardly, it simply locks the converter blades
> to the housing, for no slippage.

IOW, it COUPLES the engine solidly to the transmission input shaft.


> If I apply much power at any speed, I can tell
> it unlocks,

IOW, it DE-COUPLES the engine from the transmission input shaft, leaving
only the fluid coupling of the torque convertor.

How much more directly can I state this???

>
>
>>>it just prevents any slippage, and would slip and burn out if
>>>it were engaged under heavy load or deceleration.
>>
>>It depends entirely on the design. Some TCC clutches can handle full
>>engine torque and are just as rugged as the other clutches inside the
>>transmission. Some are much more limited in ultimate torque capacity,
>>but in ALL cases they are released during high-gear deceleration solely
>>to reduce drag and save fuel.
>
>
> If the computer shuts off fuel, how would it save fuel?

Uhhh..... by NOT burning fuel that would otherwise be wasted.


> and it has only been after reading the comments here that
> I wonder if a front wheel drive car has any steering problem
> when coasting downhill in gear.
>
> I would think rear wheel drive would provide better
> control, either with the engine, or rear wheel only brakes.


FWD and RWD cars respond differently in countless ways. Coasting versus
not coasting is about 5000th on the list in importance- its just not
even relevant.


>
> This thread is way too long, but it has pointed
> out that most cars keep the motor connected to the
> drive shaft when coasting, some fuel injected cars
> may shut off fuel when coasting but do waste some
> momentum that could allow coasting farther without
> using gas.

I give up. Some people are just GOING to believe that there's a net fuel
savings from coasting in neutral, despite having absolutely ZERO
evidence in favor and the fact that carmakers have documented evidence
to the contrary, at least when combined with deceleration fuel
shut-down. I might as well try to talk Tom Cruise out of believing that
alien souls live in volcanoes.

>
> Turning the key off with a stick shift in gear
> and turning it back on is a good way to blow out a
> muffler (sorry, catalytic converter first).

Which is why ECMs turn the damn FUEL off, not the ignition! Turning the
ignition off merely dumps raw air/fuel mix into the exhaust pipe (and
the air we breathe), while shutting off the fuel just pumps air through
the engine.


> And engineers apparently feel that the brakes
> are not dependable for stopping the car (this is
> definitely true for big trucks, but it isn't that the
> brakes are no as capable as the engine, if the truck
> attempts to go down a steep hill with a high speed,
> neither the engine or the brakes can be depended on).

?!?! "Neither can be depended on?" So just how DO the thousands of
trucks on the highways come to reliable stops millions of times per
year, anyway??? I mean, sure, things can break and sometimes do, but...
Arrrgh. So much doesn't make sense about that paragraph that I can't
even comment.

I'm just going to go shoot myself. This thread is a PERFECT example of
why fuel-saving progress has been so painfully slow. There are thousands
of well-meaning people out there who are willing to throw money at
PATENTLY STUPID ideas (like compressed air as a power source for cars)
rather than vigorously persue technologies that, while they may have
great engineering challenges, are not guaranteed to be net losers by
basic physics. Better engine management of simple gasoline and diesel
cars, better hybrids, better batteries, flywheel energy storage, etc.
are all VASTLY more promising than an idea that cannot help but discard
40+% of the energy you put into it at the front end, and then another
40+% when you try to take it out as compressed gas energy storage does.
Maybe I'm just becoming an old fart, but don't they teach "PV=nRT" in
high school anymore?!?!?

Or maybe this is just what happens when threads from "alt." newsgroups
leak into "sci." and ".tech" newsgroups. I'm going to hope and pray
that is the case, and therefore there is still hope for society as a
whole :-p

Steve wrote:
> Mike Romain wrote:
>
> > wrote:
> >
> >>Mike Romain wrote:
> >>
> >>>>Glad to be rid of your "input". There goes another one that thinks
> >>>>spinning an engine fast uses less energy than spinning it slow.
> >>>>
> >>>
> >>>What part of 'the fuel is shut off' in deceleration mode don't you get?
> >>
> >>What people don't seem to grasp is that instead of fuel, coasting
> >>momentum is now being wasted on turning the engine. It means that you
> >>coast nowhere near as far, fast or long, which in turn means you have
> >>to use fuel much sooner. Additionally, the speed the engine is turned
> >>at by the incline is much higher than idling speed, which means more
> >>energy is needed than idling would.
>
> >
> >
> > Just because your engine is in 'deceleration mode' with no gas pedal
> > input doesn't mean you have to be racing the engine or engine braking.
> > That is what the gear shift is for....
>
> And in deceleration mode, the ECM cracks open the idle speed control air
> bleed so that manifold pressure rises (vacuum decreases) making the
> engine very much easier to spin. Zoomie just doesn't have two brain
> cells to rub together, apparently.

And Stevie remains too dense to realise that energy to spin an engine
and gearbox (even fed wit air) has to come from somewhere else when
it's not supplied by fuel. Spinning the engine and gearbox wastes
momentum from the incline.

> Everyone else

wastes fuel.

> (including the
> automakers who have to eke out every bit of mileage they can so that
> they can meet CAFE requirements) seems to understand this.

They have to apply their design to comply with dumbassed laws/myths
that claim you are "out of control" without the engine engaged. Never
cycle downhill folks, you'd be "out of control" of your bicycle. Be
real careful when you change gears driving, folks, you're "out of
control" for the duration of that hazardous operation. What a pile of
horse****. The fastest way to carry out an emergency stop is from
coasting.

> From a pure
> *DRIVER* perspective, all this annoys me in new cars. They don't have
> nearly enough natural engine braking for my preferences, especially with
> automatics that additionally decouple the locking torque convertor on
> deceleration. Taking your foot off the gas already feels exactly like
> coasting (because it virtually IS).

But it isn't quite!

> But they do get amazing gas mileage
> even in very large vehicles compared to past years.

By american standards maybe.

News wrote:
> "Mike Romain" > wrote in message
> ...
> > wrote:
> >>
> >> Mike Romain wrote:
> >> > wrote:
> >> > >
> >> > > Mike Romain wrote:
> >> > > > >
> > <snip>
> >> >
> >> > Just because your engine is in 'deceleration mode' with no gas pedal
> >> > input doesn't mean you have to be racing the engine or engine braking.
> >> > That is what the gear shift is for....
> >>
> >> Quite right, however in practice you do rev the engine higher than
> >> idling.
> >
> > That 'still' comes down to the computer sending 'no' or extremely little
> > gas to the engine so the revs make no matter. That is just engine
> > braking.
> >
> > Idle uses fuel.
> >
> >>
> >> >
> >> > I can be coasting at 40 mph with my foot off the gas in deceleration
> >> > mode and the engine can be turning at idle speed with little or no load
> >> > on it. I actually do that all the time or 'drive with the tach' and
> >> > then use the gears to slow down when I approach a light or stop sign.
> >> > I
> >> > don't need the brakes until the last little bit.
> >>
> >> If I see a red traffic light in the distance my clutch goes in and I
> >> coast up to them. In this case there's probably not much in it between
> >> our methods.
> >
> > Again, you use Idle which uses fuel, I coast in gear with no throttle
> > and still need the brakes to finish stopping so I am not wasting energy,
> > just saving brake wear.
>
> A modern engine with the gas pedal off and the engine revving above a
> certain rev will cut off the fuel completely, until the revs get low enough.

...and will be wasting momentum from coasting to turn the engine instead.