Electron wrote:

> At 11.42 2011.11.25, you wrote:
> >
> >>  The trick, I imagine, would be building a
> >> carburetor for a more efficient engine.
> >>
> >
> >The current engine controllers have efficient carburation. They use
> >fuel injection with a model of the relationship between time of the
> >incoming air and its location during detonation.
>
> What does have detonation to do with normal combustion? When detonation
> occurs, the ignition time is retarded and/or the A/F ratio is made less
> lean. When detonation is not detected, it doesn't enter into the equation
> of the injection (or of the ignition) at all.

When detonation is detected the mixture for the next few cycles at that
point is leaned to oxidize the carbon particle the usual cause of detonatio=
n.

> >The fuel metering is adjusted every 2-4 microseconds to get uniform mixi=
ng.
>
> What? 2-4 microseconds means 30000000-15000000 RPM, while the A/F ratio
> is adjusted at best every revolution of the engine (2 on 4 strokes).

The fuel flow rate is being adjusted every 2-4 microseconds on some cars
actually many cars. The days of simple one shot injectors has essentially g=
one.

> It doesn't make sense neither that the ECU recalculates anything every 2-=
4uS,
> as it would be pointless anyway. Or you mean a time resolution of 2-4uS? =
Well,
> that is pretty normal, they are microcontrollers with multi MHz range clo=
cks.
>
> >There is a reason my SUV gets better gas mileage than my motorcycle.

Walter Banks
Byte Craft Limited
www.bytecraft.com

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