Jake:

About 3 years ago, at Florida Jets, Vern Montgomery was recording the installed thrust of many of the jets with his homemade scale on wheels....he may still have that data...

At the time he did my engine, Rei Gonzales' engine, and another guy with a Mercury, all externally mounted on 2 HS's and a Roo, both my P-80 and Rei's 750F were at 16.5 lbs, and the Merc was just under 16.0 lbs.
I don't remember the exact atmospherics at the time, but guessing, it probably was 85 deg with dewpoint of 65 deg, ambient pressure close to 29.92 and altitude at Flagler of about 25 ft MSL....giving a density altitude of close to 2000 ft.

As Bob noted, JetCat uses STP for it's thrust calculations. AMT NL reports their thrust at STP, and you can probably use their data for AMT USA, comparing similar engines. I know Carlos at RTI has done umpteen thrust recordings on many engine types, and also is a good source of comparative data.

My own personal experience with JetCat P-80/120, AMT USA Mercury/Pegasus, and a RAM 1000, all externally mounted, is that they all put out thrust very close to what is advertised on a standard day.



Tom