The turbos are move than proven to offer more power when everything is right. Changing only the turbo will not fix what is really causing your car to underperform. What I am saying is that changing the turbo will only cause you more frustration because it is not the root of the problem. Any turbo will under perform in your car because it does have a gremlin somewhere. The largest difference in power between different cars set up the same way (Taking the auto trans out of the picture) is Cam timing. When surfacing heads and blocks, the cam timing changes and the more things are surfaced the farther off the cams can be. This is just one of many things I have seen that can add to the mix of gremlins. Even if 50 shops throw up their arms, IMO something is not right. Best of Luck!
