5th gear problems

[mazdafreak1211]

pushing on the gas peddle full throttle then shifting is fine in all gears in my msp ,but once I get in 5th gear and push on the gas full throttle,it seems like the turbo begins to turn off by sort of sputtering,does anyone know what the problem is

 

[Speed3.5]

well when clutch goes bad , the last gear goes first and so on .
other wize if you don't get boost than you could have a leak , i did have a loose of boost like it starts than disapears for no reason even when i flored it in 4th gear.
check for those two as thats my experience tells me .