RE: Viper 500 - Best Configurations?
Claudio;
We have a class here in Nashville TN (USA) that we call Q-400. We use a 424 airframe and the TT GP 42 engine with a mandated 9-6 APC prop. This engine pulls this plane along very well. This engine tachs on the ground about 16,000 rpm and unload in the air very well. It is not quite as fast as with the TT Pro 40, but the plane is fun to fly with this engine and not at all under-powered. It too think the 9-9 prop would be way too much pitch to allow the engine to unload in the air, though I haven't tried that particular prop. I've tried 9-7 and 9-8 props but didn't see any speed increase; I did find that the needle was touchier to set though.
Doug Bebensee