Bill,
As far as I know, Tracy's controllers don't encorporate a timing change based on an accessable table. Since this is what you are using, it seems unlikely that a programmed timing change would be happening. There have been instances of problems
of this sort associated with CAS signals due to CAS mounting or signal amplitude issues.
Since the MAP fluctuation is at WOT, it seems unlikely that a leak would be the the source since the effect of a leak would decrease as the MAP approaches ambient. Possibly, there may be some pressure recovery or ram effect in your intake
system and the MAP variation might be due to airspeed variations in a less than perfectly stable atmosphere.
It is possible that at WOT the controller is intermittently usinging a high MAP table location just above what is normally attained when programming the correction table. Unless the MAP is artificially increased into this range, programming
those table locations cannot be accomplished by the normal methods. This wouldn't be a problem if the corrected high MAP region of the table is similar to the default values.
Steve Boese
RV6A, 1986 13B NA, RD1A, EC2
From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Bill Bradburry [bbradburry@bellsouth.net]
Sent: Thursday, September 06, 2012 9:26 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Intermittent hiccup
Thanks, Steve,
Tracy would have
to enlighten me about a timing change. I haven’t touched the timing from the factory settings. I will take a look at the MAP though. What do you think could be causing the fluctuations? A leak? This is at WOT. I only close the throttle if I am in the
pattern to land. I control the engine speed with the MT electric prop otherwise.
Bill B