Posted for Rick Schrameck <rickschrameck@lvcm.com>:

I did not do the test so Dave would be the one to answer everything but here
is what I know:

Dave owns a Legacy

The engine is a IO-550N

The prop as I mentioned in the original message is a Three blade MT

Prototype exhaust  ( really ugly)  Not anything like the stock exhaust

Do not know about altitude info

The airspeeds were TAS with 4 way flights using gps

Another note:  Anyone who knows Dave's 22,000 hours of being a test pilot
knows his data is correct.

Rick