Hi Paul-

 I took some time to massage the data from the final run.  I added a column
 averaging the two rotor pressures, I added a column which identifies the
 time of the most recent CAS pulse, and I computed last known RPM.

 Mark

 Mark sent the whole 9.2 megabyte spread sheet so I cut just the relevant
 stuff and plotted it. 9.2 megs is too big to publish.

 The difference in the amplitude of the front and rear rotor waves is
 somewhat of
 a mystery at the moment. It could be the way the pressure tap hole was
 machined
 in the runner tube. They were hand drilled. If it is not perpendicular you
 could get some strange effects.

 This RPM is roughly where the tubes were tuned for so you can see the
 pressure
 waves peaks happen around bottom dead center and front (car blue) and rear
 (red)
 rotors are roughly in phase and they add. Mark averaged them (yellow
 line).
 The green line is the CAS signal.

 Mark, please redo do it and just add the rotor pressures  together.
 That will give us a better idea of how much total air the engine is
 getting.
 Do not divide by two.

 The result should be well over 1.5 volts and well over atmospheric
 pressure.
 Atmospheric pressure is 1.8 volts at sea level and Mark's air port is
 6800 feet. At 6600 RPM the prop tips were near supersonic so that
 was the max static RPM of this engine at what ever power it could
 make at 6600 RPM and 6800 feet. Once the airplane picks up speed the
 engine RPM will increase and so too will the engine HP.

 BTW we are at the response limit of the pressure sensors. These are the
 same
 type Tracy is using. The data acq could sample data tens times as fast
 but for the fact the pressure sensors are not up to it.

 Right now the engine is under propped. Mark will rerun some of the data
 when he gets the right prop on there. Never the less we had to
 weigh the tail down with a steel beam to keep the airplane from
 nosing over.

 Paul Lamar

Mark-I apologize for this question, but could not remember the configuration
of your engine...is it a peripheral port exhaust or RX-8?  Is it the only
slide throttle engine now running?

Paul--do we yet good comparative fuel burn/hp data, both dyno and flight
test comparing the peripheral exhaust port/peripheral intake port engines?
You have probably addressed this many times before and if so, I apologize.
Am very interested to see how these real world comparisons work out between
the two with apples-to-apples comparisons.  We may have to prep components
to run the same engine on dyno first with peripheral exhaust port
configuration, then disassemble and reassemble with RX-8 side housings?

This is great news about operation of Mark's slide throttle.  In this
regard, does it take fairly quick throttle changes responsively?  Is this
slide throttle the teflon version you showed earlier?  What is Mark using
for air filter (have always assumed that contaminants introduced in slide
contact surfaces would be the devil's curse).

Steve Beckham


Paul Lamar

We don't really have any good dyno data but there was a Power Sport powered Velocity
In the 500 miles Dayton to OSH race and he made it on stock tanks so it could
not be too bad. He averaged 214 MPH. Here is some other Power Sport stuff
you may not have seen.

Mark's Teflon slide throttle is Rev 10 without the built in throttle
cable anchor built by Tom Weber as I recall. Mark added the anchor.

Paul Lamar