Re: sliding block, SPICA et al

[bearbvd@domain.elided (Greg Hermann)]

 FI is more efficient
>than carbs.

I beg to differ with this statement.

A well designed FI system will usually breath better than carbs, but it is
a _VERY_ rare FI system which is capable of EITHER timing the flow of
mixture with high rate air flow in the intake ports (at WOT) OR of
atomizing the fuel as finely as a properly set up set of IR Webers will.

Both the timing of mixture flow AND the degree of fuel atomization have a
SIGNIFICANT effect on brake specific fuel consumption--which _IS_ the usual
measure of efficiency!

Yes--the better breathing at WOT which is available with FI often does
outweigh the positive effects of good carbs, but it is at the cost of
higher fuel consumption. Before trying to flame, realize that I am NOT
talking about the lower fuel consumption that FI gives at part load due to
more accurate metering.

The main point is--there is a lot of room to improve output and WOT
efficiency with FI both by using a far shorter (and properly timed) duty
cycle on the injectors at WOT and by obtaining far better fuel atomization
from the injectors (air atomization??).

Regards, Greg

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