hybrid engine startup

I've only ridden in a hybrid once, but from what I recall, the engine
starts up very quietly and smoothly. Compare this to the conventional
car startup, which is rather violent, the whole car shudders. How does
the hybrid accomplish this? And why can't they make conventional cars
startup just as smooth and quiet?

because when you start the toyota the engine is not running it is
working of the battery. a light on the dash says ready.the you put it in
gear and you are ready to go. if you step down on the gas the engine
starts automatily.

In article <1142466022.325986.254000@v46g2000cwv.googlegroups.com>
[email]uw_badgers@email.com[/email] "Bucky" writes:
[color=blue]
> I've only ridden in a hybrid once, but from what I recall, the engine
> starts up very quietly and smoothly. Compare this to the conventional
> car startup, which is rather violent, the whole car shudders. How does
> the hybrid accomplish this?[/color]

Just guessing: it'll be a mixture of causes. * Small engine with
a special shock-absorber-thingy connecting it to the rest of the
drive train. * Electric motor coupled with a good control system
to even out variations in speed and load. * And, in fact, you do
feel it starting and stopping, under some circumstances (although
it is never anywhere near obvious, or jolting).
[color=blue]
> And why can't they make conventional cars startup just as
> smooth and quiet?[/color]

Maybe they will, now they know how. But a conventional engine
rarely needs to be ultra-smooth when starting/stopping, because
it does those jobs so rarely (commonly one of each, per journey),
relative to a hybrid. Also, a decently made conventional engine
can be pretty well-mannered, as-is.
--
Andrew Stephenson

The only difference is in the lack of starter motor. In a conventional car,
the starter motor turns the engine at a speed much less than the normal
idle speed of 850rpm or higher, so there is a bit of a rumble as the
engine starts turning on its own. In a hybrid the electric motor has the
ability to turn the engine at the same speed at which it will be idling
when the system starts the engine, so the trasition is much smoother.

"Bucky" <uw_badgers@email.com> wrote in message
news:1142466022.325986.254000@v46g2000cwv.googlegroups.com...[color=blue]
> I've only ridden in a hybrid once, but from what I recall, the engine
> starts up very quietly and smoothly. Compare this to the conventional
> car startup, which is rather violent, the whole car shudders. How does
> the hybrid accomplish this? And why can't they make conventional cars
> startup just as smooth and quiet?
>[/color]

What kind of car do you usually drive? I can barely feel the startup in my
cars and the noise isn't particularly loud, either. In fact, I'm not
entirely sure I can FEEL the engine in my Sienna start at all.

Besides, you do need a little feedback in the form of noise, so you'll have
some idea of what's happening under the hood.


*** Free account sponsored by SecureIX.com ***
*** Encrypt your Internet usage with a free VPN account from [url]http://www.SecureIX.com[/url] ***

Hard to believe, but true -- "Bucky" <uw_badgers@email.com> typed:
[color=blue]
>I've only ridden in a hybrid once, but from what I recall, the engine
>starts up very quietly and smoothly. Compare this to the conventional
>car startup, which is rather violent, the whole car shudders. How does
>the hybrid accomplish this? And why can't they make conventional cars
>startup just as smooth and quiet?[/color]


COST



Actually my '05 Camry SE V6 is pretty much silent at startup; the only
way to really tell that the engine's started is watching the tach. As
contrasted with the '06 xB that shudders significantly at startup.



So I repeat:


COST


($25 grand for one and $15 grand for the other)


-Don (That Was Easy!)
--
"We have enough youth; let's start looking for the Fountain of Sense." --Anon

Dave Dave wrote:[color=blue]
> because when you start the toyota the engine is not running it is
> working of the battery[/color]

yeah I know, I was referring to when the engine actually starts.

qslim wrote:[color=blue]
> The only difference is in the lack of starter motor. In a conventional car,
> the starter motor turns the engine at a speed much less than the normal
> idle speed of 850rpm or higher, so there is a bit of a rumble as the
> engine starts turning on its own. In a hybrid the electric motor has the
> ability to turn the engine at the same speed at which it will be idling
> when the system starts the engine, so the trasition is much smoother.[/color]

I think that's it. To expand on it, I don't think it's so much the fact
that the Prius lacks a starter motor, it's the fact that the Prius in
essence has a 44 hp starter motor. With such a powerful motor, it can
powerfully start the engine quickly and smoothly. Of course, the reason
that the Prius can have such a powerful starter motor is because it
uses the same motor that drives the car.

In a conventional car, they're not going to put a 44 hp motor just for
starting the car, that would be a waste of money, space, and weight.
They're going to put as small of a motor as needed.

"Motor-generator... automatically starts the gasoline engine much more
quickly and smoothly than a conventional starter motor."
[url]http://www.toyota.com/about/environment/technology/2005/engines/Hybrid-Revolution.pdf[/url]

"the engine fires up instantly. Because it uses a much more powerful
starter motor, you don't hear it spin for a second before the engine
starts."
[url]http://www.automobilemag.com/reviews/0409_gmc_sierra_hybrid/[/url]

"Bucky" <uw_badgers@email.com> wrote in message
news:1142466022.325986.254000@v46g2000cwv.googlegroups.com...[color=blue]
> I've only ridden in a hybrid once, but from what I recall, the engine
> starts up very quietly and smoothly. Compare this to the conventional
> car startup, which is rather violent, the whole car shudders. How does
> the hybrid accomplish this? And why can't they make conventional cars
> startup just as smooth and quiet?
>[/color]
Variable valve timing. At startup there's not much compression, and very
little fuel is used. I'm assuming you are referring to the Prius.

Doesn't have anything to do woth cost, Don. 6 cylinders are by nature much
smoother than 4 cylinders. This is why none of Toyotas V6s have balancer
shafts - you don't need them. If you have been in a new Highlander hybrid,
the engine on transition is absolutley seamless compared to the Prius,
where there is a slight shudder.

Variable valve timing isn't used at idle or at startup. It's only used at
higher engine speeds when under load.

"qslim" <Suckers@suckersdotcom> wrote in message
news:e9a83135e911780cba209c499ce230b7@localhost.talkaboutautos.com...[color=blue]
> Variable valve timing isn't used at idle or at startup. It's only used at
> higher engine speeds when under load.
>[/color]
Oh, so you are saying the engine is at full compression at startup? Bull.

"mark_digital©" <976XXX@nospam.net> wrote in message
news:KPGdnQf4T_k67YTZRVn-sw@comcast.com...[color=blue]
>
> "qslim" <Suckers@suckersdotcom> wrote in message
> news:e9a83135e911780cba209c499ce230b7@localhost.talkaboutautos.com...[color=green]
>> Variable valve timing isn't used at idle or at startup. It's only used at
>> higher engine speeds when under load.
>>[/color]
> Oh, so you are saying the engine is at full compression at startup? Bull.[/color]

A modern automotive engine does not have a mechanism to relieve compression
like you see on small pull-start engines like on a snowblower.

If you take a look at how the variable valve timing works, you could tell
that it is not designed to relieve compression at startup.
--

Ray O
(correct punctuation to reply)

"Ray O" <rokigawa@tristarassociatesDOTcomn> wrote in message
news:8fbe4$4419d2b9$44a4a10d$23720@msgid.meganewsservers.com...[color=blue]
>
> "mark_digital©" <976XXX@nospam.net> wrote in message
> news:KPGdnQf4T_k67YTZRVn-sw@comcast.com...[color=green]
>>
>> "qslim" <Suckers@suckersdotcom> wrote in message
>> news:e9a83135e911780cba209c499ce230b7@localhost.talkaboutautos.com...[color=darkred]
>>> Variable valve timing isn't used at idle or at startup. It's only used
>>> at
>>> higher engine speeds when under load.
>>>[/color]
>> Oh, so you are saying the engine is at full compression at startup? Bull.[/color]
>
> A modern automotive engine does not have a mechanism to relieve
> compression like you see on small pull-start engines like on a snowblower.
>
> If you take a look at how the variable valve timing works, you could tell
> that it is not designed to relieve compression at startup.
> --
>
> Ray O
> (correct punctuation to reply)
>[/color]
What you say is completely opposite what I was told by a certified Prius
tech. As load increases, whether it be at low or high rpm, so does the
compression. The engine is built much lighter because it doesn't have the
constant compression. In idle it sips gas and the compression is very
slight. Just enough to run and that's that.
mark_

not exactly.

the variable valve timing has nothing to do with the compression.

at low engine rpm, the engine has better torque and efficiency with a 'mild'
cam timing. (low valve overlap)
as the rpm increases the engine can tolerate more overlap ('hotter cam') and
make
more horsepower.
otherwise, the mild cam timing makes the engine run out of breath at higher
rpms.
this allows the engine the best of both worlds, good torque at low rpms and
great torque at high rpms.

the shop manual explains this.
if the solenoid is activated at idle, the engine stalls. the timing has too
much valve
overlap. this is a diagnostic procedure from the shop manual, too.

the engine in the prius is the same as the engine in the echo. i have a
couple.
it's a 1NZ-FE. the prius has a cover over the original starter hole, it
uses the
generator as the starter motor. it's silent and more responsive.
sammmm

--
[email]zammy@pghmail.com[/email]
"mark_digital©" <976XXX@nospam.net> wrote in message
news:sdqdnaOrPrUdkYfZRVn-vw@comcast.com...[color=blue]
>
> "Ray O" <rokigawa@tristarassociatesDOTcomn> wrote in message
> news:8fbe4$4419d2b9$44a4a10d$23720@msgid.meganewsservers.com...[color=green]
>>
>> "mark_digital©" <976XXX@nospam.net> wrote in message
>> news:KPGdnQf4T_k67YTZRVn-sw@comcast.com...[color=darkred]
>>>
>>> "qslim" <Suckers@suckersdotcom> wrote in message
>>> news:e9a83135e911780cba209c499ce230b7@localhost.talkaboutautos.com...
>>>> Variable valve timing isn't used at idle or at startup. It's only used
>>>> at
>>>> higher engine speeds when under load.
>>>>
>>> Oh, so you are saying the engine is at full compression at startup?
>>> Bull.[/color]
>>
>> A modern automotive engine does not have a mechanism to relieve
>> compression like you see on small pull-start engines like on a
>> snowblower.
>>
>> If you take a look at how the variable valve timing works, you could tell
>> that it is not designed to relieve compression at startup.
>> --
>>
>> Ray O
>> (correct punctuation to reply)
>>[/color]
> What you say is completely opposite what I was told by a certified Prius
> tech. As load increases, whether it be at low or high rpm, so does the
> compression. The engine is built much lighter because it doesn't have the
> constant compression. In idle it sips gas and the compression is very
> slight. Just enough to run and that's that.
> mark_[/color]