Twin injector system?

[Michael Kasimirsky]

I know Honda uses a twin injector set-up on their RC-45 superbikes
(750cc V-4 four stroke engines turning nearly 15,000 rpm).  One injector
is mounted downstream of the throttle plate and is used for low speed
injection.  The second injector is mounted above the velocity stack
(inside the pressurized airbox) and is used for high rpm operation.
This is done to give the fuel more time and space to atomize in since
the injector is aimed at the center of the port, instead of aimed at an
angle at the port wall.  This also allows them to use a smaller injector
for better control of the low speed mixture while still having
sufficient flow for high power, high rpm operation.

Since I'm interested in motorcycle fuel injection, this type of twin
injector set-up is exactly the type of thing I'd like to learn more
about.  This would address the biggest problem I can see for injecting a
small motor: getting sufficient "bandwidth" from the injectors.  On the
low end, the injector must be able to maintain a stable 1100 rpm idle.
On top, it has to provide sufficient fuel for a high output engine
operating at 15,000 rpm or so.  Getting that from one injector seemed to
be the biggest hurdle of the project.

Please keep this discussion on the DIY-EFI list so I can follow it.  Or,
if you take it off-line, please add me to the distribution list.  I
probably won't have much to add, but I'd sure like to learn what's going
on.  My race bike REALLY needs a fuel injection system.  :-)

Michael Kasimirsky