Min. injector off time

[Orin Eman]

> Now if that (using round numbers) injector takes 
> .002 sec to open and fire the injector is only
> open .015, and is flowing maybe not 10% less
> but alot less than it's rated amount.  As we spin 
> that eng higher, aren't we actually leaning it out
> more and more since this lag time is decaying the
> actual flow time????...

Usually, the computer takes this into account in calculating
how long the injector is open... along the lines of you
get an average of half the fully open fuel flow during the
lag time...  It will also estimate the lag time based on
battery voltage.

> consulted with RC Eng, as you approach 90
> and more duty cycle the injector Locks open,
> or Locks mid stroke, 1/2 open.

I think they would be talking about high RPMs here - duty cycle
doesn't mean much when the injector doesn't have time to
close during the 'off' time.

In fact, duty cycle isn't a good measurement... what matters is
the off time, measured in milli-seconds or so.  Depending on RPM,
an 85% duty cycle gives the injector orders of magnitude greater
time than it needs to close, cool, whatever or it could
be insufficient at (very) high RPM.

Orin.