ORIGINAL: MTK
I had a small scrape on my prop tips recently so I wound up sanding a set of matching tips on the 17x12, which now is 16.4x12
I thought the engine ran fine with the stock 17x12 but now it runs even better it seems. As Bob has found out running his 15.5x12 wide blades, the engine loves to spool up. With this apparently small mod to the prop (accidents sometimes help), I picked up a couple hundred rpm. Flying didn't change at all.
The only downside I see is that now the tank gets used up faster.
Matt,
This matches what I've seen - excellent performance with the APC 16x12 pattern prop. I still think the 15.5x12W is a skosh better.
I have a clutch of test props - some of them run less than 5 minutes - that I will sell as a lot pretty soon. Just about everything in the 18x10 to 17x13 range.