I'm pretty sure two members pushed the E3 16G to 400 whp! Obviously not on 550cc injectors and most likely not on pump gas but they should be able to offer some tuning advice on how they did it.
I'm not sure where the reliability threshold lies with that turbo though. I'm pretty sure 400 hp is going to take it's toll on the turbo sooner rather than later but G's figures above are pretty impressive if he has been running the car for that long. I'd really like to see the Dyno plot for that car. I don't know much about tuning but I understand basic concepts. High boost pressures create power but they are also necessary a lot of the time to overcome inefficiencies, bottle necks, resistance to flow etc. The more efficient you make everything the less boost you should need to make the same numbers. Assuming G's numbers are accurate, you can see a few details in his mods that allude to how he made the whole package more efficient. For the OPs goals and everyone looking to stay with a 16g on a street car, I'd say there is more to be gained by trying to take advantage of the 42-44 lb flow and increasing efficiency at lower boost pressures than trying to max out boost and head further north. Especially if you are looking for any sort of longevity.
@G ... Do you have any ceramic coating on that exhaust manifold and turbo etc?
