Originally Posted by Ivas
Yeah, I understand why an under drive pulley would be counterproductive on a blown engine. But what's the point in an over drive pulley. Why not adjust boost with the blower pulley, and let well enough alone? Is there some benefit to pulling the belt itself faster?
Because going to a bigger lower pulley gives more surface area increasing belt traction. When you go down on the Blower pulley you take away surface area and decrease belt traction.
That's the short of it