Alan Tolle wrote:

John Lynch has recently reported some data from the Kilo trials conducted at
the Porterville airport.  I seriously doubt that this data can be used as a
basis for the comparison of the speeds of the RV-4 versus the RV-6.

The glass guys invented the Kilo trials, and I have talked at length with
some of them, as well as with Kieth Livingston, who is the organizer at
Porterville.

I think the only thing the Kilo trials can show is that one airplane is
faster than another airplane.  We already agree that the -4 is faster than
the -6.  The absolute airspeeds reported are quite suspect.   There are
three reasons why this is true.

First, the course is very short with the timing being done over only about a
15 second interval.  Second, it is my understanding that the timing is done
manually by eye and hand, not electronically.   Third, the contestants can
(and they themselves tell me they do) dive just a little bit to the start
line.  All of this gets the participants some very racy airspeed numbers,
which the participants like, but  which don't mean much in the real world.
Except to say that today my airplane is faster than your airplane.

Finally, we are really not talking an apples to apples comparison in the
Kilo trials.  By the very nature of the competition, the contestants are
those who have the need for speed and have manipulated their airframes and
engines accordingly.  They vie here for bragging rights, not a valid RV-4
versus -6 performance comparison.   Van and I have done the latter.

I am not so sure Allan. My personal jury is still out on that:-)
I wonder about the same prop for the Rv4 and Rv6 that you and
Van used. According to Don Bates the prop should be optimised
for the airplane. Were you both showing the same manifold 
pressure and RPM? 

According to Tracy Saylor he thinks the increased drag of the RV4 
is due to the bubble canopy on the 4 as compared to the fast 
back on the 6. This, he thinks, is why Dave Anders is so much 
faster than he is. I don't necessarily agree. 

I just feel the increased wetted area of the RV6 has to cause 
more drag unless there is some subtle thing drastically wrong
with the Rv4.

I am still gathering  data and running drag programs.

Paul Lamar
 
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