Switchblade Turbo (check this out!)
 

Check this out found it earlier, and watch the video at the bottom of the page.

Switchblade Turbocharger --- Blaylock Turbochargers

Pretty innovative idea, single turbo and spools quick with drive pressures lower than boost!

I think Jkidd is or was working on something similar to this... I wanted more info about it but i cant get in contact with him now:argh:

Google Aurora Multi-stage Turbo. Pretty much the same idea.

great idea! Whats the cost?

I believe I saw someone say about $3500. So its as expensive as twins, but when you can run 50lbs of boost with about at 1:1 boost/drive pressure ratio, its as good as a small set of twins, and takes up less space.

Interesting concept, almost like vgt. Twins will always the the advantage of more flow and keeping both turbos in their most efficient part of the flow map. at 50PSI the 63mm is about 68% efficient.