I am 3 years into a 4 passenger amphibious airplane. Around 300 hp from a 13b turbo running around 6000 rpm's with a constant speed propeller speed around 2500 with my 2:40 prsu unit. I have the motor completed and dynoed, Haven't permanently constructed intake and exhaust as need in place to properly accomplish this task. I have been working with a design engineer and are almost to concept. Then comes structural design and actual wind tunel results. Excited to get started on actual construction.