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[BradyEng at aol.com]

In a message dated 95-12-07 18:40:02 EST, you write:

>>         I don't understand your explaination of the fuel regulator in part
>1.
>> You state that by plumbing the regulator to the intake manifold, as
>manifold
>> pressure rises, it biases the regulator in order to keep a steady 45 PSI.
 
>> 
>> I always thought that by plumbing it to the intake manifold, you
>effectively allow manifold pressure to effect change into the regulator
pressure. So,
>in effect, as engine loading increases, and manifold pressure increases, a
>corresponding increase in fuel pressure results.  What's the deal?
>
>
As long as we are speaking for Ed, I really liked the CCI articles.  They
provided a proffesional approach to hardware & software development for a
motorcycle racer with a BSME(me), and I don't think I was the target
audience.

I was supprised at Eds choice of a speed denisty system for a motorcycle
engine.  Motorcycles almost always use independent runner intake systems (one
throttle bore and carb venturi per cylinder).  If you've ever tried to
synchronize one of these systems, it is obvious that manifold pressure varies
so much as a function of crank position that I would think that it would be
useless as an indicator of engine load or cylinder filling.  I also don't see
how the fuel pressure regulator could have the frequency response to track
these manifold pressure variations.  This is less severe at full throttle,
but still present.

It would seem to me that an N-alpha system would be more applicable.

It would be possible to provide some averaging of the manifold pressurer by
using a long tube between the sensor and the manifold or manifolding the
sensor to all the cylinders. This discussion dosn't apply if Ed used
independent injectors and a single throttle point.

The article also indicated the motor was good for 70 hp. I hope this was the
stock figure, or it was downgraded to fool the competition.  Otherwise all
that was gained with FI was ease of tuning.

Once again, I really got alot out of the articles, but I'm curious about some
of the choices that were made on the mechanical side of things.

SBrady