I should clarify that the current turbo that im running is this Kinugawa one. http://shopping.kinugawaturbo.com/kinugawaturbo99-08subaruwrxforestertd04l-13t-6210hp-1-3.aspx Its basically a TD04 turbo (front cover , compressor wheel and 6cm turbine housing, with the smaller forester TF035 Exhaust wheel. Its how they are brand new. The boost does not drop off, it holds 14 psi all the way to redline. So my thinking is that the TF exhaust wheel is flowing enough not to restrict it at high revs. Im going to try the smaller turbine housing, hopefully it still holds to redline without c