16.3K is impressive for that 55- My Webra Speed-50 turned a stock APC 9x8 around 16.2 give or take 200, on the stock muffler. Between the extra size and that "red muffler"
I am not surprised!
Go smaller towards the pylon props. and let us know what happens- You are the first person I have EVER heard of running a 9x10 on a Viper style quickee-
