Greetings,

Below is the log entry for today.  As you can see, the inlet ducting does in fact cause a significant problem.  Smoothing the airflow into the TB inlets seems to help as expected, and will be built into the next airbox. 

In retrospect, I've had to improve this intake inlet ducting every step of the way, every time more power has been possible.  I can look back and clearly see how "good enough" for one rev, just wasn't good enough for the next.  Makes the turbo guys seem pretty lazy :-)

Cheers,

Rusty (butt much cooler today)

8-24-04

Re-installed the muffler now that I have about 20 inches of tailpipe welded in place.  This seems to make a big difference in the cockpit noise level, not to mention the seat temp.  It if gets rid of the exhaust smell, it’s work will be complete. 

Did a few tests with the intake, and there’s hope.  I ran the plane full throttle to get some static rpm’s and MAP readings. 

Normal setup with all intake tubing connected-  RPM 5500, MAP 27.0

No inlet tubing connected to the TB, just the 1.75” straight flanges-  RPM 5750,  MAP 27.1

No inlet tubing, but with short air horn on TB in place of flanges- RPM 5820,  MAP 27.9

From the above tests, it’s pretty clear that there’s a lot of improvement to be made in my inlet ducting.  I have to imagine that the results could possibly be better if the prop blast wasn’t blowing perpendicular to the TB inlets.  Now I just have to come up with a better inlet scheme, and things should be much better.  Not sure what that will be yet.