Bigger turbo
There's a few options and levels available here in the states. Feel free to reach out if I can be of any help. I spoke with this company at Sema and you should be able to do better here especially when dealing with core returns and all that. The performance numbers quoted are based on the larger GT2 units.
A regular 65mm upgrade will cost less and will get to 700whp, a bit more if you start with a gt2/7.2 core, but remember those dont have the recirculation valves on the turbos so you will have ti figure that out too ...



