parallel vs sequential turbo's

[law195]

I saw the previos post that <span style='color:red'>scootinintegra</span> made it sound obvious that sequential turbos would be better in a bi-turbo setup. Is there a parallel setup and what are the + - of both. not necesarrily going for a biturbo but it's good to know.

Single, big turbo = more power, generally faster 1/4 times

Twin, parallel, smaller turbos = quicker spool time, better daily driving power

Twin, sequential turbos = quicker spool time, but limited by complexity and ultimate size of larger turbo.

[Mante]

I figured this pic would give alittle more insight or the idea of a sequential turbo setup from a 3rd gen rx7 I believe. Expensive isnt the word it requires 4 valves to control the verious stages of the boost/powerband.

http://www.scuderiaciriani.com/rx7/turbosystem.jpg