Well Th Flames Is corsed By Fual being pushed into and engine on Down Revs and thereby dosn't get unuf air in with it so the remaining fual Goes into the hot exeast pipe and explodes there And becuase of the short ness u can see the flames being burnt becuase of the extreme shotness of the pipe. This won't hapen on the GTR cars in LFS becuase the exuast pipe goes all the way to the back of the car. Also with things like that Car can be tuned out in the ECU but won't afect performence but will grab the eye wich is wat advertisers like so they leave it in. The turbo bak fire is a mod mainly used by Rally cars were the engine keeps runing but dosn't ingnight all the cylinders and lets it explode into the exuast systems so it spools the turbo reducing turbo lag enormisly.