tommayer wrote:

Paul,

   My error.  I confused Anders with Sailor.  Still, Paser was pushing 240
mph with an 0-320 and a fixed pitch wood prop and big wing root fillets in
his Mustang 15 years ago.  He also had it stalling in the mid or low 50s for
the CAFE races.  I have not seen TBO figures from Paser, but my
understanding is he was figuring on getting to factory TBO.  He said he was
turning the engine 2850 rpm max.  Certainly he was not blowing jugs and
doing majors at 400 to 500 hours.
   For high altitude performance you might want to think seriously about
increasing wing area and aspect ratio.  I put 23 inch tip extensions on the
Mustang.  Stopped the washout, continued the taper, simple squared off tip
shape like an old Mooney.  Results: roll rate degraded slightly but
perceptibly.  IAS about 2 mph slower at cruise hp with exptensions on at 7K
DA.  IAS a dead heat for a given cruise horsepower at 10K DA.  IAS with
extensions on plus 5 to 7 for a given hp at FL 210.  Stall speed with
extensions on lowered about 5 mph.  Best rate of climb speed lowered by
almost 10 mph IAS with extensions on, but best rate of climb at 150 HP
improved by 200 to 250 fpm at 10K and higher.  Take off run decreased by at
least 5%.  These observations verified via GPS and experience of more than
600 hours now.  Higher aspect ratio and more wing area provide more bang for
the hour of sanding than wing root fairings by far, assuming you want to fly
high, fly fast, fly cheap, take off quick, land slow,  and are not obsessed
with Reno.
    An observation on Tracy's observation about observing the racers.  I
took about an hour of video of Nemesis in 1999.  The engine air inlets are
rectangles, which are not supposed to be as efficient as circles.
Everything on the airframe is reflexed, wings, fuselage, rudder, ailerons,
elevators, wheelpants. (I adapted a pair of Van's fat,  reflexed wheelpants
to the Mustang, and got 2 to 3 mph ias improvement over long narrow
wheelpants.) I wish I could tell the formula from the videos, though how to
apply the reflex to an existing metal airframe is beyond me. The only other
unusual thing about Nemesis that you can see are the Lanceair style upcurved
wingtips.  Again, I wish I could deduce the formula from video.  tommayer

 
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