Ram Air interested parties,

 

I asked Arnie (Race 96) to gather some data over a foreign airspace (Wisconsin) to see whatever.  He flies a nicely finished 360 with a blueprinted Lycon IO 360 equipped with 10:1 pistons, the forward mounted throttle body and unfiltered ram air delivered to the induction system.  He is currently using ordinary Slick Mags. (P-Mags are under consideration).

 

Luckily, his aircraft is held rock steady with his recently installed Tru-Trak AP and he was able to record the following:

 

First run at 10000 MSL, Baro 30.07, OAT of -2C, 2500 RPM about 125* ROP

 

WOT, 184 KIAS, 214 KTAS, 21.2" MAP, 10.9 gph

 

Reducing MAP about 1",

 

170 KIAS, 196 KTAS, 20.1" MAP, 8.9 gph

 

A loss of 18 Knots (21 MPH) true airspeed.

 

Then, at 12000 MSL, Baro 30.07, +1C OAT, 2500 RPM

 

WOT, 175 KIAS, 213 KTAS, 20.1" MAP, 9.8 gph

 

Reducing MAP 1",

 

162 KIAS, 195 KTAS, 19.1" MAP, 8.2 gph

 

A loss of 18 Kts TAS.

 

In a 400 fpm descent with a tailwind, he was hitting 272 Knots ground speed - I love our lawn darts..........

 

We fly unusually low drag airplanes, (like ground-bound Corvettes) and power really counts because the drag components are not as great as those of an oil canning, rivet filled, fat winged, STC'ed aircraft.  For us, an inch of MAP is worth a great deal in speed, efficiency or both.