Dave

Some more data on racing.

I flew model aircraft in races for a number of years. Top speed in
class was about 100 mph.

When you came up to a pylon and cut the corner tight and pulled high
G's you bled off airspeed.

We used fixed pitch props and you had two choices. With a flat pitch
prop you had lots of thrust in turn and didn't lose very much
airspeed. and would accelerate back to top speed for that prop very
fast.

If you used a high pitch prop you lost speed in the turn and slowly
accelerated to top speed on the straight away however you had a high
flat out top speed with the high pitch prop and would overtake the
flat pitch prop on the straight away. Next pylon the flat pitch prop
would turn tighter and not lose as much airspeed and take the lead
again.

Propping the engine correctly let you win races. Engine power varied
with moisture and temp so each day and sometimes each race as the day
wore on required a different pitched prop to max out the capability of
your bird.

Am sure the Reno boys have a more fancy method than we used but I
learned a lot flying in competition that could be applied directly to
GA and up aircraft.

Big John


On Wed, 07 Jan 2004 11:03:00 -0800, David Lednicer
wrote:

BllFs6 wrote:
isnt that like trying to compare a high mileage compact car to a dragster?

I don't know of any dragsters that have to pull 6gs in a corner.
Induced drag is an issue with Reno racers. When I was working with
Randy Howell, when he owned Madder Maxxx, I worked on convincing him to
fly a looser course, to lower the loading in the corners. He agreed to
go out in practice and fly three laps tight around the pylons and three
laps loose around the pylons. By his own admission, he turned much
faster laps flying loose. This was exactly what I had predicted using
my race course simulation program (which is NOT a CFD program!).