Understood. Before to buy the conversion kit because i don t have the knowledge or how to made an exhaust pipe i searched on the net what solution have chosen others. My friend with the same plane told me to buy this kit because it is well calculated. Probably he omitted to tell me that i will lose some power and also a bigger consumption of fuel. But at the end it is the first jet, after a while when i will manage the plane better will pass to the next level, F22 composite with two X45. There is a producer Christen diffusion that make a plane with the good dimensions for this. 2 m length, around 8-9 kg in function of the plane setup.