Iv been playing with a 453t with larger inj. and have been changing around diffrent housings on the to4 and have decided that it needs a larger turbo with n90 injectors, it smokes like a freight train, but pulls well. I know that the 2 cycle will not tollerate much drive pressure, so they use a large turbo that has a lot of lag, but it is the only? way to control drive pressure. there has to be a solution with todays better tech. than with the old school way. If I cant find a way to get rid of the smoke I'm limited to about factory hp levels. The 2 cycles are so touchy with back pressure , that even a muffler makes a huge diffrence on how well it runs.