Warp Stealth

whoa, that's some in depth stuff. i'll have to get back to it after tuesday sometime and really go through it.

thanks for putting all this info out there.

 

I think some who have driven bot classics and Gen2 have said that it is easier to glide in a 04+ than a classic.

 

Well written !!

Is it really 2 kW to spin the engine in warp ? I was thinking more like 0.2

 

Yes, warp stealth worked ON THE SAME CONCEPT with Gen 1s (I had two). Graham Davies discussed it. I think he's reachable by e-mail (from his website). I couldn't say that Gen 1s would mirror the graph you've done---I don't imagine so.

Two small things from a proofreader's point of view:

In the 2nd #, "delightfully" should be "delightedly". If you don't see why, PM me or ask me to explain ongroup.

The reference to "stage 4" in the third-from-last # will leave readers not familiar with all the stages nonplussed.

Basically, a good description of a little-understood Prius phenomenon. For non-techies, possibly either the very name "warp stealth" should be changed (it is, after all, inaccurate), or a brief explanation of why we call it that should serve as in introduction.

Useful!

 

Nice article!..was enjoyable to read too.

 

The site won't come up this morning. I'll check it later in the day.

Tom

 

and here i was wondering how i got two 75MPG+ bars in a row yesterday in a 55 MPH construction zone... guess i'm better off than i thought :-p

 

The article states that fuel is burned when driving in high speed in "N," yet when I do this, the indicator shows the ICE is off and nothing is being charged. It gets really quiet coasting at 80 to 85 mph down the 1/2 mile hill.

 

Before anybody crucifies me for my conjecture.. as I am speaking out of my own speculation and observation without too much knowledge of the real working parts of the prius.

Let me say, this sounds like a kick I was on here while back but finally let go because I didn't have too much foundation to explain it.
This article was a nice attempt to put in a nutshell what few seem to talk about and understand.
It gets deep into the working of the prius and its hard to defend yourself without adequate knowledge.
Most "like myself" know just enough to be dangerous and cause even more confusion as they try to explain themselves.

I thought that using the power of the ice to get up to speeds of 60 or 70, then letting go of the pedal briefly and maintaining just enough to barely maintain a deteriating speed so that in about 2 minutes you would loose about 10 - 15 mph on a flat surface... then speed up again and repeat.

This almost sounds like a modified pulse and glide technique.

I caught alot of arguement becaue many said it was foolish to use the ice to charge during the acceleration phase to then try and use that stored electrical energy to help maintain speed because electrical energy created with the ICE is never as efficient as just maintaining a constant speed?

The arguement also indicated that varying speeds was more of a waste of efficiency than maintaining a constant speed.

Its funny how we can use the arguement that anytime we use energy created from the ice, its not as efficient as simply using the ice alone and avoiding using the battery unless its from wasted kinetic energy.

I know this is going to be hard to follow as I am not explaining myself well... but suffice it to say that Toyota apparently believes using the ICE to make electric energy for later use is sometimes benificial.

Its one thing to use the ICE when the battery is "dangerosly" low, but its quite another when the ICE charges the battery when its already in an ok state.

After saying all that.... my arguement was that once the ICE is on, it likes to do some work.. might as well make electric energy while it propels the car down the road right?

Hence the benifit of the any pulse and glide technique.

I've heard Truckers talk about how thier diesels seem to run better pulling a load.
The atkinson engine seems to have some similiar properties in that it has a very high compression ratio and likes to work hard once it really gets going.

Why not make electric power when the ICE is operating at optimum efficiency so the electric can take the load when the ICE would be a waste to use like in low load situations when its not that efficient.

At any rate, the warp stealth seems to be a modified way of saying the electric helps out when the ICE is just kicking back even at high speeds with the throttle feathered, and then the ICE kicks in to regain speed while recharging the batteries.

Too bad the electric is not just a little more powerful as it seems you could maintain a speed for quite a distance even at high speeds if it were so.

Too bad we don't have the battery the Camry has in it?
I think the next generation prius with a bigger battery and higher rpm mg1 could be exciting.

 

I would like to see the real data how the modified pulse and glide technique is better than CC method.
http://priuschat.com/index.php?showtopic=19638&st=8

Ken@Japan

 

Well I do recognize that both of you guys know far more than I do about the system and I'm just throwing in conjecture on the sidelines.
The part about the glide technique I see as benificial is that if you can achieve that state, its the most friction free state the prius can achieve and then when you fire up the ICE, you put it in the most effecient state it can acheive as you go ahead an regain the speed lost from gliding..... and the battery gets charged again to help the glide again.

True glide without ICE or battery is the most desirable, but good luck on holding that for any length of time.. so in the real world, its about the battery slightly assistiing the glide... but something has to charge the battery back up right?.. its not the glide doing it... or else your gliding wrong as friction kills your kinetic benifit.
Its never good to kill needed kinetic speed to charge batteries?... charging batteries is best done with "wasted" kinetic energy or with the ICE under a "like you said" greater than 15kw load.

So we are slicing and dicing the two most efficient states of the prius in this process.

Some choose to go to neutral to glide, but that seems aweful busy to me.. I would rather learn to feather the throttle. I can see how going to neutral would be far easier, but not near as relaxing and enjoyable a trip.
I don't want to have to work to save gas... I want the car to do the work so I can enjoy my trip.

 

I can certainly attest to the existence of this 'warp stealth' regime. I've noticed this as I've been playing the Prius game when possible/practical, and have noticed the immediate switch from 'battery current only' to the ICE kicking in. The mileage figures I've been getting support this, as I'm ready to post into the 'I beat the EPA' stickie. I've been consistently above 55mpg highway, with my figures at ~58-59 mpg.
My driving is mostly (about 90%) highway (as opposed to expressway) driving. I consider myself very lucky when seeing the other posters showing pics of their MFD with 60+ mpg, but also showing a 15 mile trip in an hour! You can have the stop&go, and great that the Prius works as it does in that congested rural setting. That is really helping the cause. No, my normal commute is 12 miles, no stoplights, all highway, no traffic, can drive whatever speed I want. I turn onto the highway from my driveway, and turn off into my parking lot at work. OK, there is a 45mph zone, then 35mph zone as I get into town to my workplace, but that only helps!
Anyway, when driving in the 50-60 mph region I've been able to use this technique, as I've been trying to attain the classic pulse & glide at those speeds. Depending on SOC, I've been able to get there at 50+ mph speeds, but for short periods of time.
It's a game, for sure, but can be fun & rewarding to get that fuel economy.
Thanks for this post and the good information.

 

<div class='quotetop'>QUOTE(judibob @ Jun 1 2006, 09:45 PM) [snapback]263968[/snapback]</div>

Would you please try to measure mileage using the CC method below?
http://priuschat.com/index.php?showtopic=19638&st=8

Thank you,
Ken@Japan

 

There is no one more annoying when driving someplace like the NJ turnpike who does not keep a constant speed with cruise. I think at 65+ the cruise cotrol does a pretty good job. Otherwise in more trafficy situations try the pulse- it does seem to work better.
Lucky those of you who can play with the road to yourself!!!!! :lol:

 

I checked the link you included in your comment. I thought this driving style was more or less common sense.
In any case, this is usually the way I drive. I drive this way in non-hybrids as well, especially those with automatic transmissions. As you'll notice, many times an AT-equipped car will downshift & actually accelerate when faced with a stiff uphill while in CC. So, over the years, I've gotten into the habit of going off CC in this condition. Now, in the Prius, I also go out of CC going downhill to take advantage of getting the powertrain to do what I prefer.

<div class='quotetop'>QUOTE(ken1784 @ Jun 1 2006, 09:34 PM) [snapback]264391[/snapback]</div>