Heres a project I been tinkering around with.
It is originally made by a company called sound performance and is highly patent protected....

It will succesfully close one half of a twin scroll housing to divide the a/r for quicker spool. This housing will go from a 50a/r housing to a 1.00 a/r housing at full boost. The turbo I will test it on is that Borg warner turbo I got from the wreckers. After talking to Justin and a few other Turbo Gurus, weve decided that it should be at par with an HX35 7blade. or a borgwarner s256. Both turbos are choked by their bolt on housings.. but suffer from too much lag in their stock t3 housings.

At the moment Im just fabbing up a quick down pipe and setting it up on my mock engine. more pics to come.