EMILY COWEN wrote:
> > Fuel injection generally gives more performance because it's
> > adjustments and tunings can be done without compromise, generally
>
> Nope, it gives more performance because the internal combustion engine
> is an AIR PUMP, and f/i, being less restrictive in the intake passages,
> allows the engine to breath better.
That is exactly what I am saying. One of the "compromises" with
carbs is that you must have some sort of venturi restriction to
give a low pressure area to carburate into. This is a carb compromise,
to get a more aggressively low pressure area to suck fuel out
of the jet, you need more air flow over the top of the orifice. This
is a compromise, fuel injection doesn't not have this problem.
> For instance, one of the hot
> performance modifications to the Mustang 5 litre f/i is to replace the
> throttle body/opening (I don't know the name of it) with a larger one,
> so that it will flow more air than the stock one. You are faced with
> the same compromises with f/i design as you are with carburation.
I don't see how this relates. What this says to me is that
5 liter throttle bodies aren't as big as they could be. But
that's not surprising, exhausts aren't as big as they could
be, and air filters are more restrictive than some aftermarket
brands.
Obviously I am not saying that every fuel injected car is
the most optimized machine possible. There are still compromises
in terms of cost, emissions, and engine life.
But the basic compromises are gone. Another example, the
enrichment pump of a weber. In a carb, it can only enrich
while the throttle is moving forward. When the computer detects
wide open throttle in a fuel injected car, it can enrich
for as long as desired. Simple simple things, that would
take an entire new mechanism with more bits and tunings
to accomplish in a carb, with fuel injection, it's trivial.
--
Trevor Boicey
Ottawa, Canada
tboicey@brit.ca
http://www.brit.ca/~tboicey/
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