Repitching Sensenich 72x85 prop on RV-7A

[jayres]

I am only getting about 201 mph full throttle @ 6500' msl. Other relevant data: RV7A, O360-180hp, static rpm: ~21-2200, climb: ~14-1500fpm, full throttle rpm: ~ 2750rpm, cruise speed @ 2400 rpm: ~175mph.

I am considering repitching my prop to around 88. Does anyone have any experience with doing this and what did repitching do to/for your performance? Thanks, Jimmy Ayres, RV7A-O360-180

[gasman]

You have the correct prop. The one that Van wants you to have. Trust him. You need to know your manifold pressure so you can understand what the motor is doing.

DON"T REPITCH!!!!!!!!!!

[Hawkeye7A]

I'd leave it alone. First time you get into a high altitude airport, you'll be glad you have 85" instead of 88". My Ed Sterba wood prop may be a bit underpitched at 82" but my home base is 4780 msl. By the time I get to pattern altitude I'm mountain flying and like most RVs I'm at pattern altitude by the time I cross the departure numbers. "I can make it better is the mortal enemy of perfect enough."

[hecilopter]

altitude and drag on the airframe that is not that far out of line. I have the blended airfoil prop and I only see about 206-208 MPH true airspeed full throttle and 2700 RPM at 8000 DA. If I go down low to 500 DA in smooth air at full throttle and 2700 RPM I will see about 212-214 MPH true airspeed. With a fixed pitch prop you probably can't run full throttle down low due to overspeed, so you can't get a top speed because you aren't producing full HP from the engine.