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cposer
12-04-2020, 05:05 PM
I am still learning how my Airmaster prop works and how to manage it and the engine. But I have a few questions.
What are most getting RPM wise on take off?
Does the take off RPM change with density altitude?
What do you like to see for climb RPM, Climb manifold pressure?
What do you use for Cruise RPM, Cruise manifold pressure.

I really like the performance but still an uncertain about the quirks.

rv9ralph
12-04-2020, 08:28 PM
I am not familiar with the Airmaster, but ... More information is needed. What model Kitfox? What engine? Inflight adjustable? If so, what prop control is installed? etc.

Ralph

P Johnson
12-05-2020, 02:24 AM
I am still learning how my Airmaster prop works and how to manage it and the engine. But I have a few questions.
What are most getting RPM wise on take off?
Does the take off RPM change with density altitude?
What do you like to see for climb RPM, Climb manifold pressure?
What do you use for Cruise RPM, Cruise manifold pressure.

I really like the performance but still an uncertain about the quirks.


This link will take you to a service letter explaining Rotax manifold pressure and constant speed propellors.

https://legacy.rotaxowner.com/si_tb_info/serviceletter/sl-912-016-r1.pdf

Floog
12-05-2020, 10:37 AM
Model 7
912 ULS
Edge Performance Fuel Injection (Scott's wonderful idea!)
AirMaster w/Whirlwind blades

Takeoff: 5,800 RPM (Adjust fixed stop in the prop hub to achieve this.)
No.
Obstacle climb: 5,400 RPM, Full power if needed
Cruise climb: 5,300 RPM, 24-25", 85-90 MPH
Cruise: 5,200 RPM, 19 - 21" gives great fuel economy and speed

95% of MY flight ops is with 'reduced power' including most takeoffs

P Johnson
12-05-2020, 11:23 AM
Model 7
912 ULS
Edge Performance Fuel Injection (Scott's wonderful idea!)
AirMaster w/Whirlwind blades

Takeoff: 5,800 RPM (Adjust fixed stop in the prop hub to achieve this.)
No.
Obstacle climb: 5,400 RPM, Full power if needed
Cruise climb: 5,300 RPM, 24-25", 85-90 MPH
Cruise: 5,200 RPM, 19 - 21" gives great fuel economy and speed

95% of MY flight ops is with 'reduced power' including most takeoffs

Floog, sorry for the thread drift but are you running a 70" prop, what economy and speed do you get in cruise, as this is the set up I am looking at.

Floog
12-05-2020, 12:29 PM
70" blades. I get 3 1/2 to no more than 4 GPH overall. Less than 5,000 ft. speed 110- 115 mph. Just yesterday, I did a FULL POWER cruise at 5,400 RPM at
3,500 ft. that yielded 137 MPH TAS. My plane has Desser 850 tires (tyres?). Coming across the Cascade range last night with a 20 mph headwind, I had a higher than normal power setting. At 83% power or 22" mp at 9,500 ft, I was doing 130 mph TAS.

P Johnson
12-05-2020, 02:13 PM
70" blades. I get 3 1/2 to no more than 4 GPH overall. Less than 5,000 ft. speed 110- 115 mph. Just yesterday, I did a FULL POWER cruise at 5,400 RPM at
3,500 ft. that yielded 137 MPH TAS. My plane has Desser 850 tires (tyres?). Coming across the Cascade range last night with a 20 mph headwind, I had a higher than normal power setting. At 83% power or 22" mp at 9,500 ft, I was doing 130 mph TAS.

After an RV8 and RV4 and wanting something more fun that will do for me:):):).