I'll soon be on your tail!! I won a RHB3 turbo on
ebay for 355.00 I'm going to somewhat copy you but mount it on my 150cc OMG engine I know where to get the 150cc for around 400 bucks and its oil cooled and comes with cooler carb and everything! Let me know if your interested I'll give you the contact info. If you want to make more boost close off the port in the turbo on the turbine side like a VGT turbo does. I think it should work. New Diesel motors use the VGT turbos (for smog) and will make 5 psi boost at an idle!!!! thats 600 rpms. All it does is open and closes the port size that blows on the turbine wheel with a sliding collor. Its all computer controlled because you can very easly overspeed the turbo. I was BSing with an enginear and he said when they first came up with the idea they were testing it and the turbo spooled so fast the shaft fell threw the housing and hit the floor, no man mad oil could keep up with the speed!