mkiv supra max rwkw on original turbo?

[coolio_sag]

Hi to all, I'm new on this site and was wondering how much rwkw could i push out of my 96 original sequential turbo with modifying the internals/wheel etc. I own the jap spec model which has the 440cc injectors and the ceramic turbos. I wanted to achieve 350rwkw is this possible? I find it hard to believe but Ive heard that people are getting the original turbos to have up to 450rwks with high flowing them and replacing the wheels with larger titanium ones. I want the car to look and be as original as possible even if it means less power. Thanks