OK, I may need to give out more information.

For one, the only modifications allowed to the TT40 is head shim thickness, prop size, and/or glow plug types. You can't take the baffles out of the muffler. You can change out bearings if you wish, for worn or new engines.

Fuel used is Ritch's Brew Pylon 15%, all synthetic oil.

By the way, APC 9 x 6 sport prop does not do all that great on this short of a course with a heavier, draggier airplanes of the Sky Raider or LA Racer.