In before the debate
There's a big thread on -7's vs -9's vs -5's.
Basically summed up like this.
-7's 300kw turbos Great response
-9's 350kw turbos close to -7 response
-5's 400kw turbos laggy on normal capacity. Why have big turbo's running at medium efficiency? Why not get 7s 9s and when/if you build the engine get some 5s?
The question is are you using it for street, track?
You can get the -9's for the same price as the 7s and 5s. You just have to haggle.