sorry for the dumb question, but I was wondering if a quick spool valve will have any benefit on a single scroll turbo?

thanks

 

No. As soon as the exhaust passed the qsv flapper, the air would rush to the blocked of the turbine housing. Then, it air would enter the turbine just like if the qsv wasn't there.

Basically you would be making a restriction in the turbine housing without making the air flow through the housing at a faster velocity. It would probably hurt spool and definitely hurt power.

A qsv on a twinscroll turbine (single scroll manifold) makes all of the exhaust flow through one of the scrolls. The increased velocity and manifold pressure is what makes the turbo spool faster.