I was using the application 'SpeedBox' on my iPhone. It sounded too high to me as well, but that what it read, multiple times. We were out on the SF Bay, it was calm, but we may have had a tail wind.
Any suggestions for a more reliable speed indicator?
But, bottom line is, we don't care about top speed. We're looking for as the previous poster suggests, the right prop overall. And so long as our tach is accurate, we have found it in the Spitfire, topping out at 5800 RPM at WOT.
Sound right?
