IVO IFA Adjustment

[cainbird]

Ok Guys,
I have been playing with my Ivo in flight adjustable prop and I am wondering how everyone else is using theirs. Once I reach my desired cruising altitude should I bring in some pitch and open the throttle to full open then bring the rpms back to say 5200. Is it ok to keep the power wide open and lug the engine back to 54 or 5200? Should I have a manifold pressure gauge? Ideas or input would be great of anyone has any.

Thanks~Cain B

[DBVZ]

I will also be interested in seeing what the Rotax experts have to say about this. But I don't think you could call 5200 or 5400 lugging the engine. See the attached file. Torque drops off pretty fast above about 5000 RPM while HP keeps going up with RPM. I wonder about the relative speed/fuel numbers of setting the pitch for cruise at 5000 RPM vs at 5400.

[kitfox2009]

Hello CB

Here`s how I run mine. 912UL IVO IFA Patriot (ultralight) on a Model 5 Vixen.
I did not install any "stops" on the pitch control. I put the toggle switch about 1 inch left of the throttle shaft. Push left fine pitch/right course. I operate it with my index finger and hand on the throttle shaft.
During run-up I check the prop operation, and then set it about 2 "clicks" left of fine pitch.
Full throttle on take off is 5500+ (careful not to over-rev). Might need a click to the right.
Maintain full throttle and 5500 during climb out and as I start to level off, pull the throttle back an inch or so and left click a couple of times to maintain 5000 RPM.
In level cruise I usually set the throttle out about an inch or more and adjust the prop for 5000.
Downwind I reduce pitch and throttle almost at the same time but have pitch back to "2 clicks left of fine" before turning final.
I am not sure if this is the RIGHT WAY but It seems to work well for me.
It made a huge difference in performance over the fixed pitch that now hangs on the hanger wall!! Have fun with it.
Cheers
Don

[kitfox2009]

CB
My manifold pressure ranges from 27 to 29 inches at climb and cruise configurations.


CORRECTION I push the toggle LEFT for course and RIGHT for fine. All other info is accurate,I believe.


Don

[kmach]

What is the manifold pressure telling you in relation to power, rpm ? Is there a maximum and minimum for the Rotax engines ? I would be stepping into a new realm with the inflight adj and the manifold pressure gauge. I would like to learn the ins and outs. i am seriously considering the Magnum Ivo inflight adjustable for my KF5 912ULS , but again am a little apprehensive .