Well I saw T-34(Joe) yesterday and I made a boo-boo
. I miss quoted him. His OS 55 was turning a 10x8 @ 15k not 16k. Sorry y-all.
I did manage to put the Ultrathrust on my 55 and got a nice surprise. On my Goldberg tiger II (40 size) I run a 10x7, 3 blade Master Airscrew for clearance, climb rate and braking. The 55 with stock muffler and baffle was 11,700 and with the Ultrathrust it jumped to 14,000 backed off 300 rpm rich. This is about 2 Hp at only 14k.
I would not hesitate to recommend this combo for performance sport. Low noise, hover with fast climb out, cool running, fuel efficient and great speed. Now let’s see how the engine holds up. Last week Joe was lapping me, now I'm got him by 3-5 mph.