Can't remember where I read it, but superchargers are supposed to benefit greatly from increased diameter exhaust pipe and high flow catalytics and mufflers. I know there were some headers made that went on the vehicross back in the day, but I heard they didn't do much horsepower wise and developed cracks rather soon. I would PM or email Tone since he probably has more experience in the area than most. I would also try to search some of the older posts containing dyno information after the supercharger install. Just remember that usually higher flow exhaust usually gives out horsepower at the cost of low end torque, so unless you've done gears on it, it might be a little slow on the uptake.