[Diy_efi] sequential injection timing

[Eric Fahlgren]

>         but there is a gentlemen who not only did a injection setup like this
> he went even further,he used the valve seat as the place of entry for the
> fuel and realized the heat int eh seat for fuel vapor. his acheivement in
> combustion efficency is remarkable. he recorded using .035 lbs of fuel per
> hp. thats a 30% improvement over convetional injection and considering he was

I believe Honda has built production engines in this range,  the CRX HF of
the early '90s had claimed BSCF in this range.  Not that hard for the
"gentleman," as he didn't have to compromise on anything else (like
performance or emissions), but plenty hard for Honda what with EPA and
customers to satisfy.

Vaporization may enhance BSFC to a point but it is to the detriment of power,
as the vaporized fuel consumes valuable space that otherwise would be taken up
by oxygen.  The beauty of the Weber is that it _atomizes_ fuel properly, with
lots of fuel particles 8 microns or smaller, thus allowing for high fuel density
and low BSFC simultaneously, maximizing both efficiency and power.

I wonder if the Audi guys with their direct injection are bypassing atomization,
and just vaporizing fuel in the chamber (shoot it on something hot)?  This would
result in the good burn/high HP numbers and lowered BSFC, and could be accomplished
if they time injection after the intake valve is closed.  At the very least, they
get good shear at the huge pressures they run (something like 23kpsi at the rail).

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