Thanks for the explanation of the prop and drive ratio. That clears up a
bunch. How does Tracy get past the brick wall thing with his drive

ratio? Can

he maintain 200mph? Can't imagine a rotary going that fast! I like that!

Skip

He may have a bit more power than most. He runs 6300 RPM max
as I recall. Perhaps his prop is a bit less pitch or diameter.
I also think he would agree his prop pitch is less than optimum.
His engine has the 1993 turbo big port end and center housings with the
earlier high compression rotors as I recall. Bruce Turrentine built it.
Perhaps it has a mild street port. Tracy is also using a tuned
intake manifold on the dynamic chamber principle.

If Tracy changed to a 2.85 to one PSRU ratio IMHO he probably would be

seeing

around 210 MPH and 8,000 RPM.

Paul Lamar

But I can go faster than 210 mph NOW! (at a lot less than 8100 rpm)   In the
first annual rotary air race (10-27-01) I averaged 202 mph including a start
at around 130 mph, a 180 deg pylon turn, very turbulent air and less than
WOT.  On a standard day, my top speed was around 215 mph.  I recently lost
2 - 3 mph with the installation of a new muffler (custom Spintech,  see
http://www.spintechmufflers.com ).  Speed loss was due to dirty aerodynamics of
exposed muffler, not HP loss.  I actually gained HP with the spintech (and
lost some noise).   Engine rpm at 215 mph is 6450 rpm.

Tracy Crook
tcrook@rotaryaviation.com
http://www.rotaryaviation.com

Well then 230 MPH!!!!! You better by God enter the Sun 100 this year
at Sun & Fun. I am counting on you, or Greg Richter to win the $500 prize. There is
still a lot of money in the Everett Hatch Memorial Prize fund.
I would love to see both of you enter. There is prize money for first and 
second in the rotary engine category. If you do I think we can come up with 
some prize money for the EAA NC to OSH race as well.

Paul Lamar
 
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