Subject: Innovate mixture monitor
From: Rotary Engine
Date: 6/6/2005, 6:09 AM
To: AA-me

    >
    > Paul,
    >
    > You wrote that the Innovate wide-band mixture monitor provided
    > misleading data during your dyno session. Do you think that you
   just got
    > a defective one or have you or Mazdatrix heard reports that their
    > product isn't generally reliable? It doesn't look like there are
   other
    > off-the-shelf low cost wide-band competitors on the market.
   Others cost
    > $1000 and up.
    >
    > Barry Gardner
    > Wheaton, IL
    >
    > Dave Lemon mentioned to me he has tried several different brands
    > and found them all unreliable. This one was about $400 as I recall.
    > That is hearsay of course but I have no direct experience. An
   interesting
    > thing about it was the built in system
    > voltage display. It was off by about a volt when compared to a VOM.
    > I suspected that the separate voltage supplied to the injectors
    > using Tracy's wiring scheme was dropping and therefore reducing
    > the speed at which the injectors opened. What caused me to suspect
    > this was the system voltage display in the Innovate.
    >
    > That is when we got the VOM and checked the system voltage. The way
    > Dave has the dyno wired is; he uses a three 12 volt battery bank
   wired
    > in parallel. The alternator on the test engine is not wired to
   this bank of
    > batteries. I therefore suspected some strange effects from
    > this unregulated source of 12 volts. When we started monitoring
    > it with the VOM it was much more stable than indicated
    > by the Innovate voltage monitor. In fact very stable indeed.
    > Why Innovate monitors and displays the voltage I know not. Unless
   of course
    > they are NOT regulating the voltage in the unit they are using
    > to evaluate the mixture!
    >
    > Well in any event we are going to hook my dual channel
   oscilloscope up to
    > the injectors today and monitor the pulse width to see what is going
    > on with the mixture suddenly going lean at high power. That and
   hooking a pulse
    > generator to the CAS input, and a hand vacuum pump (engine
   simulator)
    > will allow me to pre program Tracy's mixture settings. Pictures
    > and data at 11 :)
    >
    > Paul Lamar
    >
   Paul,
   Electronics are not my strength, but shouldn't the injectors be
   running off the alternator voltage of ~13.8 - 14.5 volts.  Doesn't
   voltage affect the time that it takes the injectors to react to the
   commands of the EC2.  It seems that the lower battery voltage would
   lean the mixture.  Please educate me a little if voltage doesn't matter.

   Ken Powell
   Bryant, Arkansas
   501-847-4721
   RV-4


Well yes. In the airplane they certainly do.
In actuality any voltage high enough to supply enough current
for the solenoids will cause the injectors to open. Perhaps
not as snappy as they should but we are seeing massive
mixture changes from the Innovate mixture monitor
that could not be explained by injector sluggishness.
It jumps from 13:1 to 20:1 with out warning sometime.

BTW that brings up the issue of alternator failure
causing the injectors to quit working perhaps before
Tracy's computer quites working. Tracy uses voltage regulators
in the computers that keep the computers working properly down
to about 6.5 volts or perhaps a bit less.

Paul Lamar


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