[kjewer1]

THe difference between those turbos is the compresor wheel. They all use the same TDO5H turbine wheel, and the housings are interchangeable but slightly different (6cm on the 14b and 7cm on the 16/18g). You can get the comp wheel swapped to a bigger one, but then you have to have the whole thing basically rebuilt while you are in there (300) plus have the compressor housing recut to fit the new wheel (150?), all on top of the cost of the wheel itself. Not very economical when you look at the price of the 16gs. Even the EVO3 is cheap now. I will second the suggestion to skip the 18g, it's not going to do any better than an EVO 16g, and it's hardly anybetter than a regular 16g. The next size up is 20g or 50 trim.