silly queston has anyone checked that the timing isnt out? if the fuel aint buring properly it certainly dont spin the turbo up properly.

also is your cam timming correct? cvh will run a tooth out either way and all it does is limit the engine performance witch leads to low boost.... again a partial burn only exhausts half of the pressure to the turbo housing.....therfore not spinning the turbo properly

have a look ....nowt to loose..L