Installed the Z1 Post MAF's and HKS drop in filters today. Then I took it for a test spin. My but dyno and VDC ingagement ratio dyno both tell me that it did provide some extra power. It increased the intake noise more than I thought too at high RPM. I figured since the stock box is retained that it would have no noise changes but the high flow filter along with the elimination of the flex pipes does provide a good volume increase. Great simple and inexpensive mod.
