Stratified Charge DI with EGR (was: AFM

[Mike (Perth, Western Australia)]

At 07:32 PM 11/3/2000 +0800, Bernd Felsche <bernie at perth.dialix.com.au> wrote:

>>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!

Aye - I'm a bit perplexed here, are we talking diesel if not but, talking
petrol then I would have expected wide open throttle to consume more
petrol due to maintaining  AFR ?

On the occasions I have wide open throttle on my vehicle I'll either
chew up huge amounts of fuel and/or leave rubber, but then my EGR is
minimal...

In the event the engine is undersized/powered in comparison with an AFM
or MAP only setup then I suppose there is value - but are you saying with
this fly by wire that gradual pedal pressing under load by human can result
in wide open throttle plate by fly-by-wire.

70% EGR does sound awfully high though, any observations that this is
used on turbo engines. And on the n/a ones is there much attention to
EGR cooling ?

By the way whats does conventional "WOT" stand for ?

The stability and PID equations must be interesting ;-)

>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.

This sounds bizarre, especially as I would have expected AFR to be kept
as close to stoich (or slightly) lean unless its a diesel...

Can you please clarify particularly this last paragraph of yours ?



Rgds


Mike Massen

Ancient Sufi saying:
        "Should your God save you from adversity, choose another God"

Pictures of site installation at Mendulong near Sipitang, Sabah (Malaysia) for
container based RAPS...   http://www.wantree.com.au/~erazmus

Vehicle modifications on GMH Turbo, twin tyres, possible 175Kw at wheels
Preliminary pictures at http://www.wantree.com.au/~erazmus/Twin_tyre_vehicle/

My editorial on twin-tyre opinion and good reference about tyres:-
http://www.geocities.com/MotorCity/2195/ttyreopinion.html

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