Twin injector system?

[Bruce Plecan]

-----Original Message-----
From: Michael Kasimirsky <mtk at tmc.astm.cmri.cmu.edu>
Subject: RE: Twin injector system?

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.
  How about two ecms.  Run the first one closed loop,  like for
an emission cycle,  but at about 70% stop increasing the inj pulse
and phase on a second ecm.  By phase I mean start the injectors
off at 30%VE.  Keep this second ecm alive all the time, ie rpm
tps, and all inputs but have the fuel VE tables all zeros to like
60K/Pa.  Then by starting them low any air is purged, and bingo.
All the fuel you want,  for the real high stuff would be P+H's.
Then say if you wanted to run injectors 2x as large at high rpm,
again run the lower ones to 70%, but bring the next stage on at
15%..
    Would have to tell the ecm some big time lies, like it's a v-8.
Course the only practical way to even start something like this
is to bench model it.  hehe.



>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.
>
>Michael Kasimirsky
>