What is the biggest prop you ever ran on your engines?
For a year ago there was some complaining about some of my engines being loud [] so I started with large props to keep the noise down and discovered the huge static thrust as a bonus[sm=thumbs_up.gif]

I was amazed today how well my 13 years old Super tiger S90K turned the APC 17x8@7800rpm with a quiet pipe and perry VP-30.
Irvine 72 on the same setup is turning a APC 16x6@8600rpm, on a shorter pipe lenght it did 9100rpm but was more difficult to setup.
All the figures are on 10% nitro and at sea level.