DIY WB update

[Bruce]

From: "Greg Hermann" <bearbvd at cmn.net>
Subject: Re: DIY WB update


> At 12:30 AM 8/14/98, Bruce wrote:
> >Speaking of lean cruise.
> >I can't find any real big gains in going real lean anyway.  Still need to
> >burn x amount of fuel to make a given amount of power to actually move
the
> >car.  Maybe, better results, in a lighter car, but then you give away all
> >the road hugging weight.  the instant you have to run more throttle
opening
> >from the leaner AFR, then your using more fuel anyway due to the greater
air
> >flow.  While you might run 10% leaner, if you have to use more throttle
> >opening you might be using a larger total amount of fuel.
> >Just completely the opposite of what pumping loses would dictate.
> >Again, theory falls short of real life....
> >Bruce

> Gearing is part and parcel of tuning. Gotta go to a taller gear along with
> the leaner af ratio--which cuts the quantity of air back down to where it
> was before the throttle got opened a bit more. The extra load on the
engine
> from the taller gear allows the wider throttle opening and consequent
> reduction in pumping losses.

Also, that assumes that the engine is still operating in an efficent rpm
range.   It's easy to lug and engine with too much gearing and then have
even worse economy.

> Part of the reason for higher power on the rich side of stoich is
selective
> burning of the hydrogen in the fuel before the carbon gets burned. The
> hydrogen fraction has a higher heat of combustion than the carbon does,
> hence more heat and power for a given amount of air with a somewhat rich
af
> ratio, but less mileage because not all of the fuel (some of the carbon
> part) is being burned.

Isn't that the reason for having to add timing, when going, leaner?.
Bruce
>
> Greg

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