It's not massively clear from the picture as to what colour the smoke is(or at least not to me) On saying that I think I'd lean more towards the blue than white, blue been oil getting burnt. Now if the turbo was the last thing to be played with I'd start there, there is a chance the seals have gone in the turbo, checking the turbo outlets on both hot and cold side should give you an idea. Failing that oil *could* be getting into the combustion chamber a number of ways, valve stem oil seals, piston rings, scored bore or could even be a incorrectly rebuilt breather system. (White smoke is coolant been burnt. There are less ways this can happen but could be more expensive, head gasket been one of them, but I don't think it's white personally) Ultimately, I'd take the car back to they guy that has done it and argue the toss, he sold you a turbo that's possibly duff Loud pipes save lives