Stratified Charge DI with EGR (was: AFM measurement/backpressure)

[mike mager]

Bernd Felsche said, in part:  (complete quotation below)

>Throttle-by-wire. The driver sets the amount of torque required by
>the position of the pedal. The ECU adjusts throttle, EGR (up to
>70%), injection and ignition accordingly.
>
>The complication has its rewards; 15% less fuel consumption, partly
>due to increased "volumetric efficiency" because the throttle is
>often wide open... better find an updated abbreviation to replace
>WOT!
>
>The engine uses quantity-regulation at low load; the torque
>developed depends on the amount of fuel injected. The amount of air
>sucked in and ignition timing have little effect on torque.


Hey!  Where's the air-fuel ratio - way lean?

Thanks,
Mike  (I see it in Diesels, but it's new to me in SI engines)


>From: Bernd Felsche <bernie at perth.dialix.com.au>
>Reply-To: diy_efi at diy-efi.org
>To: diy_efi at diy-efi.org
>Subject: Stratified Charge DI with EGR (was: AFM measurement/backpressure)
>Date: Sat, 11 Mar 100 19:32:00 +0800 (WST)
>
>Ade + Lamb Chop writes:
>
> >At 09:34 11/03/00 +0800, Bernd Felsche wrote:
> >>>>None that I can recall.  Lucas/Bosch systems use them, and
> >>>>patent leasees of them.
> >>>>Numerically probably MAP is most common, then hot wire, and then
> >>>>combos of MAP/hot wire.
>
> >>>So what is the best way?? The rover system uses MAP and inlet air
> >>>temperature...
>
> >>Even hot-wire is passé. :-)
>
> >How does hot wire work?? Is is a little heater that uses X power then you
> >measure the temperature... more airflow the more heat is taken from the
> >heater?? Surely you would also need air temperature, or am I completly 
>off...
>
>Done with either a reference wire or by a separate temp sensor.
>
> >>The latest Bosch MED Motronic (for direct-injection (DI),
> >>stratified-charge gasoline engines) uses a version of hot-film
> >>(HFM5) that's sensitive to the flow direction. That's necessary with
> >>the DI system because they run it with WOT at low loads, using
> >>controlled, external EGR to reduce the engine's output - by varying
> >>its displacement if you like.
>
> >That sounds incredible complecated... So presumuable there is no direct
> >throttle cable... just a fly by wire pedal and ecu does the rest???
>
>Throttle-by-wire. The driver sets the amount of torque required by
>the position of the pedal. The ECU adjusts throttle, EGR (up to
>70%), injection and ignition accordingly.
>
>The complication has its rewards; 15% less fuel consumption, partly
>due to increased "volumetric efficiency" because the throttle is
>often wide open... better find an updated abbreviation to replace
>WOT!
>
>The engine uses quantity-regulation at low load; the torque
>developed depends on the amount of fuel injected. The amount of air
>sucked in and ignition timing have little effect on torque.
>
>--
>Real Name: Bernd Felsche
>     Email: nospam.bernie at perth.DIALix.com.au
>      http://www.perth.dialix.com.au/~bernie - Private HP

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