So far I'm not finding the 20G to be laggy at all. I think Jared is of the same conclusion. His spool up is insane. 355whp is within the range of a 20G. The thing I like about the 20G over stock is the top end you get with it over the stock turbo. granted it's nothing like the top end you see with a dominator 3.0 or a 35R but it is a great upgrade to the stock turbo for moderate to low extreme power goals and it doesn't need a whole lot of expensive supporting mods but as Fuji said you can pull the real potential of the turbo with some well though out mods. Done write it would be the only turbo upgrade you would need for a while. It seems you have most of it already. If you don't have it already you should replace your fuel pump. And for 355whp your intake is going to be to small. You will likely hit the top of your MAF. A 72mm or larger will be a better match. An TGV deletes are a must.
And a good tune!!!!!!!!!!!!!
You are wise to stay with the top mount for the 20G, This will help with the spool. Spearco and Process West are good from what I here but you really need to go to their websites and look at the specification. Flow, Pressure drop and Delta.
I use a cheap ebay special and I have no complaints. (let the flaming begin) :lol:
Check out
my journal and
Jared's also