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OBIO
September 24th, 2009, 10:16
Tolling around in the AH Skyrocket, and got to thinking: What manifold pressure should I be running at? What RPM should I be running at for cruise?

Are there general guidelines for each engine (such as Wright R-1820, Pratt and Whitney R-1430, etc) or did it differ from plane to plane? Does anyone know of a site that breaks down the operation parameters for various aircraft engines?

OBIO

Cazzie
September 24th, 2009, 10:53
OBIO, I just use throttle and prop settings, I have no idea on rapid roadsters like this. On the Skyrocket, I get good cruise at 50% throttle and the prop RPM cranked down just a notch. I use rich fuel when flying below 10,000-ft and lean the mixture a bit above that as needed. Trim as needed, the sim Skyrocket trims real easy.

In real flying on an Aeronca Champ, I can cruise all day at 2,100 RPM, don't even have to trim much.

Attached is a 2-D panel view showing the setting I use for cruise.

Caz

Tom Clayton
September 24th, 2009, 11:06
I generally go by the green arc in the gauges and hope it's right. For mixture leaning, I rely on either a fuel flow or horsepower gauge. I adjust the mix until I get either gauge to peak and then I know I'm running where I need to be. After takeoff, I try to keep the manifold pressure at the top of its green arc. On blown engines it will stay there until you get a bit higher, then you have to adjust periodically during the rest of the climb along with the mix. I don't think prop pitch effect is modeled all too well in FS9, but I pull the pitch back untill the prop RPM is in the green for cruise, and then flatten out when I start my descent. I just wish that doing that would increase the drag like it would in the real world.

dogknot
September 24th, 2009, 11:16
I do pretty much the same as Tom and Cazzie if there are no OP manuals to read. Watch the gauges and go on past experience.

You can get close and still be safe in the sim. RW, besides the powerplant there is airframe, electrics, mass and balance, etc. to consider...not to mention pilot experience and his/her strengths and weaknesses.

Here are some free checklists that are very well done. They have some powerplant settings, etc. included that will get you close.

http://freechecklists.net/ (main page)
http://freechecklists.net/simchecklists.asp (straight to the available checklists)

If you're in to purchasing manuals
http://www.aircraft-manuals.com/ind.html

fliger747
September 24th, 2009, 12:23
R-1820?

Not having the references handy, I'd try maybe 45" for tko and max rpm, 34" and 2250 for climb and 27" and 2100 for a reasonable cruise. The max will all depend on if it is a two stage supercharger, which for a tactical bird, it probably would be.

Somewhere in that ballpark.

t.