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

Tracy Crook wrote:

Tom,

Was that a 23" total wing extension or 23" on each wing?  I'm planing on a
modest wing extension on my RV-8, probably in the range of 9 - 12" on each
wing.  Also, did you do any reinforcement to the spar at the critical point.
Critical point on the -8 is where the spar reinforcement ends on the C
channel web.

Tracy Crook
rws@altavista.net
www.rotaryaviation.com

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