Glide, yes. Pulse? What's that?

[harper42]

I thought I understood the pulse and glide technique, getting the screen to the No Arrows state. But I was reading about the Japanese gal who gets 115 mpg, and it says she Pulses up to 60 something, then glides down to 30 something. My question: How do you PULSE up to a certain speed????

[M. Oiseau]

Pulse refers to accelerating with the ICE (internal combustion engine) at a throttle setting yielding no arrows to or from the electrical system.

[eagle33199]

Pulsing can actually be more challenging than gliding (if you're trying to do it right). Basically, the idea is to get the ICE operating at higher revolutions, because it's more effecient there. So you quickly accelerate (don't floor it, thats too high) up to a certain speed, then glide back down... the sweet spot of pulsing is when you have arrows only from the ice to the wheels and the ice to the motor to the wheels, and nothing going to or coming from the battery.

[efusco]

Remember, too, her "60" is in KMH, not MPH, likewise the 30.

[TonyPSchaefer]

My personal awakening was I think Evan's document which showed a picture of a pulse achieving something like 16MPG. Up to that point, I tried really really hard to keep the real-time MPG up as high as possible. As you can imagine, I was often frustrated. Now I just try to make sure the ICE is propelling the wheels and topping off the battery at the same time.

[harper42]

<div class='quotetop'>QUOTE(TonyPSchaefer @ Aug 18 2006, 02:07 PM) [snapback]305551[/snapback]</div>

My personal awakening was I think Evan's document which showed a picture of a pulse achieving something like 16MPG. Up to that point, I tried really really hard to keep the real-time MPG up as high as possible. As you can imagine, I was often frustrated. Now I just try to make sure the ICE is propelling the wheels and topping off the battery at the same time.
[/b]

NOw I"m confused. One post says arrows from IEC to wheels and back, none to or from battery. Another post says to have IEC power wheels and battery. I just drove into town and it's really difficult to reach that point with no arrows to or from battery. Any tips on how to do that?

[hobbit]

It doesn't really matter. Again, the whole "deadband" myth is just
that -- whether the battery charges or not during a pulse is ENTIRELY
dependent upon its current state of charge, always seeking 60%, and
where you happen to have it at any given time is not something you
have a lot of control over. The torque and power curves of this
engine are very forgiving, so exactly how hard you pulse, as long
as you're running under load but not reaming it hard, just doesn't
matter a whole lot. Your best bet is to install a tachometer, and
then you can pulse somewhere in the neighborhood of 1800 RPM [for
the lower speed ranges] which will put you right in the sweet spot.
If you can hear your engine and judge that RPM by earball, go for it.
Otherwise there isn't a whole lot on the MFD that's useful, except
perhaps the instantaneous but what's "optimal" there slides all
over the place depending on wheel speeds.
.
Suggest you get over to http://www.cleanmpg.com/ and read Wayne
Gerdes' excellent "pulse and glide" article, with pictures and all.
.
_H*

[theorist]

<div class='quotetop'>QUOTE(hobbit @ Aug 18 2006, 08:11 PM) [snapback]305634[/snapback]</div>

Your best bet is to install a tachometer, and then you can pulse somewhere in the neighborhood of 1800 RPM [for the lower speed ranges] which will put you right in the sweet spot.
[/b]

The engine map for our engine that I just saw in a presentation linked by ken1784 indicates that the engine is most efficient around 2300 RPM. Is 1800 RPM more efficient due to the PSD at low speeds? Is it to extend the pulse cycles a bit due to losses with engine start-up and shut-down? I haven't verified the accuracy of the engine map.

[TonyPSchaefer]

Tomorrow I'm driving up and back from the Milwaukee Hybrid Group meeting with the injured but ever-teaching Wayne Gerdes as my passenger. I'm sure that by this time tomorrow I'll be a professional. So perhaps I should hold off on this, but I've already started so I'll finish.

I've always been working under the assumption that "Pulsing" was when the ICE is powering the wheels and charging the battery whereas "Gliding" is when nothing is powering anything.

The one on the left is Glide, in the middle is Pulse, and on the right is Oolong, a rabbit with a pancake on his head.

[Bill Merchant]

<div class='quotetop'>QUOTE(TonyPSchaefer @ Aug 18 2006, 09:42 PM) [snapback]305756[/snapback]</div>

The one on the left is Glide, in the middle is Pulse, and on the right is Oolong, a rabbit with a pancake on his head.[/b]

And Oolong's ears are flattened, clearly a Pancake Spatial Deformer (PSD).