I don't know much about turbos but regarding CA smog, I have to believe you CAN make them legal in regard to emissions testing. How many cars are sold with factory turbos? Enough to make me believe it can be done.
Found this at
Racing Beat:
"What does it mean when an aftermarket product is advertised as "CARB Exempt" or "50 State Legal"?
Although a part may be advertised as "50 State Legal", this may be more of a marketing statement than reality. Unless an emissions sensitive part has been issued an Executive Order number by CARB, or an EPA exemption, the part is NOT legal for street use. Parts that are typically appointed CARB exemptions include: headers, air filter/intakes, turbo kits, and supercharger kits. Parts that are typically not eligible for a CARB exemption include, but are not limited to: OBD II replacement catalytic converters (as of early 2005, only a few 1997 and later OBD II catalytic converters have been granted an exemption), downpipes or headers that remove or relocate a catalytic converter, and performance carburetor kits. Contact the manufacturer of a product that you are considering purchasing for details regarding that specific component.
An exhaust system that is installed AFTER the catalytic converter is considered a "cat-back" system and is considered emissions legal. (Sound level restrictions may be an issue in your state, check with the exhaust manufacturer or you local authorities for more information.)"
You're right about one thing, though. If you go in there with the dump pipe on it, it will not pass the visual inspection.
--Wag--