Originally Posted by Nixlimited

Again, for the sake of everyone else reading this thread, let's be clear. What most people who have had turbo cars are referring to when they say "spool faster" is reducing the point in the rev band where the turbos hit some boost level. For example, if I say that my new exhaust made my turbo spool faster, typically I mean that whereas I used to hit X psi at 4000 RPMs, now I hit X psi at 3800 RPMs. Thus, the turbo spools faster with reference to the RPM band.

What you are saying is different and misleading. Certainly if you can accelerate through the RPM band (under load) faster, you will be able to spool your turbos faster as measured from some point in time because the car is more powerful and able to get to that RPM point faster. However, you will not be able to spool the turbos any faster with reference to your RPMs because the pulleys do not affect exhaust flow in any way at all. Using our example above, you would still hit X psi at 4000 RPMs with or without the pulleys, however, it may take you 1/2 second less to hit 4000 RPMs because of the increase in power. Turbos run off of exhaust flow, plain and simple, and anyone who thinks a pulley is going to make their turbo spool faster is kidding themselves.