Twin injector system?

[Michael Kasimirsky]

> This ain't at all my idea, but here goes.  So ya want to go from idle
> to 15,000 rpm, hmm.  At 15G, the inertia of the timing injector ain't
> even
> gonna be in sync with nothing, so that would be the true
> reason for them mounting the injector so far upstream, the other
> sounds like a press release.
> 
I believe the idea of mounting the injector above the velocity stack
came from Formula 1.  As far as I know, this is the typical installation
in an F1 engine.  I'd thought it was for a performance enhancement due
to the sky high revs that F1 engines turn, but finding good technical
info on F1 engines isn't exactly easy.  Also, F1 cars use injectors
different than your run of the mill Buick, as you would expect.

Ducati uses twin injectors on it's superbikes (996cc V-twins), but they
are mounted in a more conventional location.  Only Honda uses the second
injector mounted upstream of the throttle plate.

For my application, I'm only interested in maximum power and
driveability.  I could care less about emissions, especially since I run
115 octane leaded racing gasoline.  :-)

One major point to consider in mounting a second injector above the
velocity stack, and throttle plate, is throttle position.  I don't think
you'd want to start flowing fuel from this injector until the throttle
is at least 3/4 open, if not wide open.  Otherwise, I could envision
many potential bad things from dumping fuel into the airbox with no
place to go.

My thoughts on system design would be to control the injectors
separately.  Size the downstream injector to get you to wide open and
maybe 1/2 of redline.  This would keep that injector small and allow
better fuel metering at idle speed.  Beyond that, I'd have the second,
high flow injector begin to kick in and supply the engine to redline.  

That said, I'm an ME, not an EE, so I've got plenty of ideas on what to
do and very little knowledge in exactly how to make this thing happen.
I'm hoping to take a course or two on microcontrollers to get my feet
wet in the near future.  Along those lines, if anyone can recommend a
good book or tutorial on microcontrollers I'd be most appreciative.
I've looked a bit at the Motorola documents and that kind of thing, but
I need to walk before I can run.

Michael Kasimirsky