changing smoke files

[canadiannational1996]

I tried to change the smoke of the bullied pacific with the flying scotsman smoke, i renamed all the bin files which were main smoke,secondary smoke and stationery smoke so they could be compatible on the bullied but then when i launched the game as soon as i clicked on the bullied it froze and said something bad happen.The reason why i did this was for better framerates.If anyone knows the process and could explain to me how to do it i would really appreciate it.

Thanks